An information center within the network for AGRECOL sustainable agriculture in third world countries

NATURAL CROP PROTECTION

based on Local Farm Resources in the Tropics and Subtropics

ILEIA P.O. Box 64 r.ahv <%tnll 3830AB LEUSDEN VJttUy kJlUII The Netherlands Tel. 033 - 494 30 86 Title page:

Leaf and fruits of a Neem tree Drawing by Wolfgang Lang

Last page:

Twig of a Neem tree Photo by Gustav Espig

Preparation of herbal insecticides Photo by HEKS, Zürich

Idea and text:

Gaby Stoll

Illustrations and layout:

Katrin Geigenmüller

Translation:

John Coates

Printing and binding:

F. & T. Müllerbader Filderstadt, Germany

© Margraf Verlag, 1986, 1987, 1988, 1992, 1995, 1996

P.O. Box 105 97985 Weikersheim Germany

The book is also available in French, German, Spanish and Thai.

ISBN 3-8236-1113-5 C O N T E N T

Foreword 5

Introduction 7

How to use this book 10

Principles of preventive crop protection 14

Pests in field and store 23 Rice 25 Maize 34 Legumes 44 Vegetables 50 Fruits 64 Storage 69

Methods of crop and storage protection 80

FIELD CULTIVATIONS Insecticidal plants 81 Mixtures 122 Animal substances 124 Ashes 127 Baits and traps 129 Other methods 138

STORAGE PROTECTION Principles of preventive storage protection 141 Insecticidal plants 146 Vegetable oils 163 Mineral substances and ashes 165 Other methods 167

References 168

Index 179

Current activities 185

Request for information 188 ACKNOWLEDGEMENT

I should like to express my grateful thanks to all those persons who made it possible to present this practical guide in its present form.

Above all these are my colleagues Almut Hahn and Mathias Zimmermann, who were always ready to listen and talk things over, and who arranged the financial framework. Berchtold von Steiger and Helmut Hess made important criticisms and further in­ spired me. Thanks I also owe to the team of the Project-Consult, namely Marie-Luise Gebauer, for the exchange of reflections and information. Josef Margraf also deserves my thanks, not only for undertaking to publish this book, but also for the bottles of red wine we shared while discussing it. Katrin Geigenmüller has won­ derfully enlivened my rather dry text with her beautiful illustra­ tions. Dr. K. Carl of the Commonwealth Institute of Biological Control and Dipl.-Biol. C. Hellpapp, a member of the Organisation for the Promotion of Agriculture and Environmental Protection in the Third World, critically reviewed the manuscript and John Coates took considerable trouble with the English translation. Finally I am grateful to all those people who contributed funds or helped to raise funds as mentioned on page 5 and 6.

Further I should like to express my deepest thanks to all those persons who have contributed important material. Some have gone to great trouble to describe local plant protection practices on paper or to compile their information, namely Blauw W., Burgess M., ILEIA, Peries L., Rankin J., and many others. This book has gained greatly in quality due to their help and co-operation.

Last, but not least, I want to heartily thank Jürgen Trautner who did a huge job on the key words and Katrin Geigenmüller who completed the make up of this book with untiring energy. Many thanks also to my colleagues at the Centre for Appropriate Technology who were so considerate and helpful during the final steps of the manuscript. Thanks for the fantastic teamwork!

Langenbruck, January 1987 Gaby Stoll

4 FOREWORD

Three years experience at AGRECOL (1983-86) have shown that fre­ quently at the crucial moment the practitioner has no access to the most recent results of agrarian research or the treasures of Univer­ sity libraries. On the other hand, the most valuable experiences of farmers based on decades of observation are seldom written down.

This book attempts at least partially, to overcome these obstacles to information flow, and to present a specific subject of our scope in a simple and understandable, although by no means complete, way. The intention is to make existing knowledge more easily accessible and to present it in a form which encourages farmers to make their own trials and to experiment further so as to widen our knowledge. This is a typical exercise in transmission for an information and contact centre like AGRECOL.

We express our hopes that this book - end of 1988 edited in French, Spanish, German, Thai, and English (3rd edition) - may fulfil its task as a useful guide for the practitioner and send it on its way with every good wish - a way that calls for a permanent improve­ ment, deepening and fulfilment.

We extend great thanks to Gaby Stoll who, after working at AGR­ ECOL, studied this subject deeply and with great engagement. From many and widely scattered sources she collected the material and ultimately presented them in this book.

The finances were contributed by individuals and institutions with whom we maintain friendly co-operation. Without their open ears our endeavour could not have been carried out:

Mr. Gunnar Videgard, Grasse, France

AGKED: Association of the Churches Development Services, FR Ger­ many

5 AGRICO: Producer-Consumer Cooperative for Biological Horticulture, Basel, Switzerland

CTA, Technical Centre for Agricultural and Rural Co-operation, Ede-Wageningen, Netherlands, supported the French trans­ lation.

IFOAM: International Federation of Organic Agriculture Movements

MISEREOR: Catholic Church Aid, FR Germany

PROJECT-CONSULT: Frankfurt, FR Germany (due to an information exchange)

Protestant Church Congregation, Schwanden GL, Switzerland

John Coates, a friend of the Centre for Appropriate Technology in Langenbruck, who often worked with us - either with shovel or typewriter - has dedicated himself with great personal engagement to the translation of the German manuscript into English.

Georges Bray did the same for the French translation and Mrs. Irene Steiner and Mrs. Milda Jelenis of F.U.N.A.M., Argentina, for the Spanish translation. The author Gaby Stoll, actually working in Thailand, just recently sent us the first copy of the book in Thai language.

Thanks to all of them!

Langenbruck, December 1988

Matthias Zimmermann Director AGRECOL

6 I. INTRODUCTION

7 This book wishes to offer a contribution to the reflections about crop protection and the agri-"culture" connected with it. Sugges­ tions for appropriate solutions to pest management problems are pointed out. Having in mind the political and economic background of the crop protection problem one can notice that there is a need to look for long lasting and reliant solutions for the agricultural practice, solutions that respect the requirements of man and envi­ ronment.

Natural methods of plant protection have assumed a new impor­ tance in an age when a host of commercial products is available which seems to offer an easy answer to the problems of fighting pests and diseases. However, these have neither solved the purely agricultural problems of the small farmer, nor have they improved his financial situation. On the contrary, they have resulted in a series of consequences which politically, economically, ecologically and socially are self-defeating.

The aid programmes of the international development organisa­ tions are often based on western technology. The instruments of this "high-input-agriculture" such as extension services, credits to small farmers for seeds, fertilizers, pesticides etc. tend to ignore and erode inherited experience and traditional systems. The fast and radical destruction of "traditionally-developed-agriculture" has considerably worsened the economic and social security of small farmers. The problem of crop protection is aggravated by the policy of companies who profit from the fact that their products cannot solve the actual problems of the small farmers.

Nature herself has offered us a profusion of plants for use in crop protection; a potential which deserves our interest. In natu­ ral crop protection we are applying nature's own instruments. Even though they seem to belong to another age, they can still to­ day contribute to an appropriate pest management the more as they are minimizing the risks for farmer, consumer and the environ­ ment. Furthermore, scientific investigation can do much to improve their applicability and effectiveness, thus modernizing their use.

8 It is hoped this book will make a contribution to this aim and motivate people to work for the rediscovery and further develop­ ment of a natural and more independant crop protection and to strengthen the belief in our powers of observation and judgement. It is we who decide how we exploit and treasure the vast variety of resources which are locally availabe at all places.

Langenbruck and Hohberg January 1987

Gaby Stoll Dipl.-Agrobiologist

9 II. HOW TO USE THIS BOOK This is a practical guide to inform farmers, advisers, experts of development agencies and scientists about the protection of crops in field and store with natural resources. It is based on simple technology which can be practised by the farmer himself. It deals mainly with the steps to be taken after an infestation has occurred. Preventive measures are considered as at least equally important. But in this book they are touched on only briefly.

STRUCTURE

The structure of this book derives from the situation that a farmer encounters an infestation in a specific crop in his field.

In chapter IV some important pests are presented. The choice for the pests described depended on the availability of natural control measures and was restricted to food plants. For these pests the life-cycles and habits are detailed in order to allow control measures to be understood more comprehensive. The control measures recommended for each pest fall into two categories:

* Preventive measures These are dealt with in chapter III and are especially described with reference to specific pests.

* Curative measures These are described in chapter V and practical details given.

All methods of control which are described in chapter V receive a reference to the respective page.

SOURCES OF INFORMATION

Four principle sources of information have been used:

* Information gathered by an inquiry among contacts of the AGRE- COL INFORMATION CENTRE dealing with natural crop protection.

11 * Answers to several 'Call for Information' published in newslet­ ters and international magazins concerned with organic farming, ecology, networking etc.

* These two categories contain much information drawn from prac­ tice. Much of this kind of knowledge lies in the hands and heads of farmers and has never been written down.

* Research from the period between the two world wars. During this time alternatives to the crop protection of the "arsenic age" were sought. White colonial farmers learnt from native popula­ tions that there were certain plants which possessed protective or repellent properties against pests. They planned to grow and process plants with such properties so that they could be sold as insecticides. From this period stems the most important research into insecticidal plants. In the post Second World War period this was quickly superseded by the rapid development of the convincingly effective synthetic pesticides.

* Research after about 1980 which was again concerned with insecticidal plants. After it became obvious that the use of synthetic pesticides carries grave problems, a renaissance of insecticidal plants began.

PRACTICE - RESEARCH

Scientific research into insecticidal plants has produced import­ ant information about their properties and potential effectiveness. But often these information are not very suitable for the farmer's purpose. They are rather focused on producing preparations on a commercial scale.

Scientific results which contribute directly to the practical work of a farmer have been integrated deliberately into this manual. They might give useful suggestions for experimentation in the field.

12 INCOMPLETENESS

This book makes no claim to be complete. It sets out to stimulate an interest in and to revive knowledge based on "people's science" as well as to make the results of research available to farmers.

The informations for the actual measures are to be considered as a basic information. In the respective situation factors such as climate, elevation and season can all influence the results and variations should be tried to suit local conditions. This is particularly so in the case of insecticidal plants because the concentration of the active substances can vary greatly. This is also true for the transference of scientific results to farm conditions.

CALL FOR COLLABORATION

In the interest of an exchange of practically-oriented information and of a mutual learning, the writer would be most grateful for any additional informations on the use of Natural Crop Protection Measures.

Thus, the process of cooperation could be enhanced and the pre­ sent level of information be realized and extended in a further issue.

Please write to the following address:

Gaby Stoll Bühlengasse 2 D-7609 HOHBERG 1 FR Germany

13 III. PRINCIPLES OF PREVENTIVE CROP PROTECTION

14 In agricultural systems where synthetic products are not used for crop protection, farmers use a series of direct and indirect measures to safeguard their crops from the ravages of enemies. In this sense "Integrated Pest Management" has long been an integral component of good farming practice. The most important factors in these traditional methods of crop protection are the utilisation of a pest's biological characteristics in such a way that they combat its development, and reducing the possibility of pests using cultivated crops as a means of sustenance. Further protection can be given by encouraging the development of natural enemies.

Crop protection is a complex process which requires an under­ standing of the interactions between the environment, methods of farming and the predominant system of cultivation. Hence, crop protection cannot consist in only one specific measure, but re­ quires a suitable combination of methods depending on crop, cli­ mate and region. A knowledge of these factors must play an impor­ tant role in the way a farmer decides to protect his crops.

It is not the function of plant protection to ensure maximum pro­ duction. This is an aim imposed by man. It is better to strive for an optimum ecological and economical relationship which leave other life forms space and resources. But when pests threaten the safeguard of food and human existence, it is not easy to not re­ gard them as enemies.

It is important to recognize that a natural crop protection mea­ sure as described in the book is to be understood as one measure amongst many. It does not pretend to replace preventive cultural measures, but to supplement them. Generally, the short term effec­ tiveness of natural measures is not as great as that of synthetic pesticides. But in the long run it is obvious that they have the following advantages: They

* diminish the risk of pests building up a resistance to treatment.

* have a less destructive effect on the natural enemies of pests.

* diminish the risk of secondary outbreaks.

* are less harmful to the health of either humans or farm animals

* cause no damage to the environment or to water supplies.

15 * mean no dependancy on a constant supply of agricultural chemi­ cal to the farmer.

* can cost much less.

Subsequently, the essential principles of preventive crop protec­ tion measures through cultural practices are described. Practical examples shall visualize them.

1. Knowledge of Agricultural Ecosystems

A knowledge of the way in which cultivated fields and the sur­ rounding countryside are ecologically associated is helpful to a farmer when he is deciding which preventive measures are best suited to his requirements. Farmers, and even more importantly, advisers, should consider the following:

* Species of pests and beneficial insects on the cultivated land and in the neighbouring countryside.

* Biology of pests and beneficial insects (morphology, life-cycle, breeding behaviour, feeding habits etc.)

* The rhythmic patterns of insects at different seasons and their dependence on environmental factors.

* Vulnerable states during the life-cycles of an insect which offer a suitable means of controlling it.

* The season or stage of development of a cultivated plant when it is most vulnerable to attack.

* Alternative host plants (either cultivated or wild) which might attract a particular pest.

* Predators and parasites which might be encouraged.

Constant observation is highly important to gain a vital knowledge about these interactions. This is a valuable instrument for the proper decisions and measures most suited to local conditions.

16 2. Mixed Farming and Diversification

Traditional agricultural systems present a landscape of great variety. In the fields many different crops grow simultaneously side by side, and wild flowers and plants add to the diversity. This multiformity itself already offers a considerable degree of preventive protection which follows naturally from mixed farming for the following reasons:

* There is a greater availability of small habitats and a multi­ plicity of food sources, e.g. nectar and pollen, on which natu­ ral enemies are able to draw. Thus a higher permanent popula­ tion of the predators and parasites of pests is maintained.

* Visual and aromatic attraction by host and non-host plants as well as the micro-climate influence the movements and migration behaviour of pests in particular localities. Mixed farming offers many forms of attraction. Pests can become confused or disorien­ tated and thus are unable to detect or discover their food plant. Repellent effects also reduce the spread of pests.

Some examples from practical experience:

* When maize and peanuts are planted together, infestation by the maize stalk borer (Busseola fusca) is reduced. Predatory spiders (Lycosa spp.) control the maize stalk borer much more effectively than when maize alone is grown (89)

* Maize and cowpeas planted together are subject to significantly less damage from the stalk borers Busseola fusca and Sesamia calamistis (148).

* A mixture of maize and beans reduces infestation by the fall army worm (Spodoptera frugiperda) (155).

* Tomatoes planted in rows between cabbages, reduces damage by the diamondback moth (Plutella xylostella), but do not prevent it entirely (89).

* Potatoes planted in conjunction with onions, beans, soya beans tomatoes and maize were significantly less affected by the pota- toe tuber moth (Phthorimaea operculella) (32).

* Potato-wheat and potato-maize combinations offer some protection against the potato flea beetle (Epitrix spp.) (32).

17 The opposite effect can also take place. In some cased mixed cultivation increases infestation.

3. Land Formation

Non-cultivated sites like steep slopes or inaccessible places, the vicinity of hedges, or marshy areas where perennial plants grow, offer numerous habitats for birds, reptiles and insects which prey on pests. From these highly varied locations complex plant colo­ nies can develop which offer living space to predators. Pests which infest cultivated crops are liable to reduction when many such natural habitats abound because they form a natural link in the food chain. Furthermore it is evident that an abundance of perennial growths such as bushes and trees encourage the develop­ ment of a stable population of predators which annuals do not. Areas with permanent varieties suffer less disturbance from outside and local fauna can breed undisturbed.

4. Crop Rotation

The basic principle of crop rotation lies in separating a parti­ cular pest in space and time from its host plant. The interruption of the life-cycle by introducing a non-host reduces the spread of pests in subsequent cultivations. It is therefore best to choose crops for successional plantings which have few common enemies. The best effects result from the successional planting of crops which belong to different families (89). Crop rotation is highly effective for controlling pests which originate in the soil like nematodes, wireworms and cutworms.

An example of a crop rotation pattern which is successful in Nicaragua (121):

* ROOT OR TUBER CROPS LEAF OR FRUIT CROPS GRAIN CROPS

Potato, sweet potato, Cabbage, salat, pepper, Maize, beans,

carrots, cassava. chilly, tomatoes.

18 * Potatoes - Beans - Maize (32).

5. Natural Rhythms and Optimum Planting Season

Choosing the right time for planting also keeps infestation low. An outbreak of pests or disease is usually associated with a par­ ticular stage of development of the host plant. The coincidence of an increase of pest population with a crop's most vulnerable period should therefore be avoided. A knowledge of the life-cycle of an insect and the corresponding effect on the host plant is ne­ cessary to enable a farmer to reach the right decision. No definite rules can be laid down regarding these fluctuations; they are al­ ways to be observed locally.

* Rice farmers in Southeast Asia who adhere to traditional methods cultivate only one crop of rice during the rainy season in order to interrupt the life-cycle of the rice stem borer (95).

* In Ghana the farmers only plant maize in the main rainy sea­ son. In the lesser rainy season maize suffers a higher infesta­ tion of stem borers (HESS, pers.comm.)

* Simultaneous planting over a large area means that the period of time when all plants are at a vulnerable stage of develop­ ment and attractive to pests is restricted. Successional plantings prolong the risk of infection.

* In Colombia the incidence of jassids in beans is reduced when the beans are sown 20-30 days after the maize. This can pro­ bably be attributed to the fact that the maize shelters the jas­ sids' food plant and makes it more difficult for them to detect. Damage to the beans is reduced by 66 % compared to monocul­ ture (103).

6. Manuring and Plant Health

The health of a plant and therefore its value as a food are di­ rectly connected with disease and pest infestation. A plant which is undernourished is in a state of imbalance and is more easily prone to the pressure of pests or diseases. Treatment with too much fertilizer can have the same results.

19 The introduction of modern inputs like artificial fertilizers and irrigation often encourages pests. Highly fertilized crops attract insects more strongly and can build up and support large popula­ tions. An increased incidence of aphids is a typical example of how large applications of artificial nitrogen encourages pests. On plants which receive high doses of nitrogen, mites were observed to lay ten eggs per day, while on those with lower doses they lay on average only 5.4 per day (161).

In Nicaragua VAN HUIS observed that invasions by the fall army worm (Spodoptera frugiperda) and the stem borer (Diatraea lineolata) were encouraged by treatment with artificial fertilizers (154).)

The opposite condition of imbalance, i.e. undernourishment' and stress, also renders the plants more vulnerable to pests.

A well formulated and balanced manure and a healthy organic soil contribute a strong resistance to disease and pests.

7. Soil Tillage

Soil tillage as a preventive measure aims at pests which exist as larvae or pupae in the soil or in crop residues. Ploughing affects them in two ways:

* Eggs, larvae and pupae can be ploughed in to a depth from which they cannot succeed in resurfacing.

* Are they exposed to the surface by ploughing they will dry out or are devoured by birds or other animals (154).

The introduction of the plough as a preventive measure in warm climates should be carefully weighted against its harmful effects such as the destruction of humus and soil erosion.

* In the Philippines, cowpeas and mungbeans were sown directly onto undisturbed stubble. The stubble impeded the detection of the peas and beans by bean flies, thrips and jassids (95).

* It is reported by Nicaraguan farmers that 'white grubs' can effectively be ploughed out when the soil is dry. The exposed larvae then shrivel up in the sun (154).

20 8. Choice of Variety

In combination with other methods the choice of plant variety constitutes a further means of reducing attacks by pests. Breeding and selection of special varieties is by no means new. In tra­ ditional systems of cultivation farmers have long been familiar with a wide choice of local varieties which were appropriate to their particular needs. Secondary substances such as gossypol in cotton or alkaloids in lupins play an important role in resisting pests or disease. With modern breeding and its emphasis on high yields, many of these protective properities have been lost. Today new attempts are being made to breed varieties with specific pro­ perties of resistance.

Resistance can take a number of forms:

* Insect will not accept a plant as a food source, a place to de­ posit eggs, or a habitat.

* Insects sicken after feeding on the host plant.

* Host plants can tolerate insect feeding and recover again (45).

The following food plants (among many others) have resistant varieties:

* Sorghum varieties resistant to sorghum shootfly.

* Cowpeas resistant to aphids and jassids (161)

* Beans resistant to beanflies (45).

* Maize resistant to the stem borers Busseola fusca and Sesamia calamistis (Nigeria).

* Rice resistant to the brown plant hopper (Philippines).

9. Field Hygiene

Field hygiene is a measure aimed at interrupting the life-cycle of pests. This includes, for instance, the removal of harvest resi­ dues or prematurely fallen fruit, which might be infested with larvae or pupae. Preventing the further development of pests in this way reduces future populations.

21 * To control maize stem borers, Nicaraguan farmers burn the stubble after the harvest, which destroys many of the remaining larvae or pupae. Some farmers turn out cattle to graze the stubble (154).

* According to KUMAR, burning stubble destroys 96 % of the larvae and pupae living in (83).

* Fly-infested fruit should be gathered together in one place and removed so that the maggots may not continue their life-cycle in the ground. The fruit should then be immersed in water for two or three weeks or buried deep (126).

10. Social Aspects

Plant protection also has a social aspect. An individual farmer cannot take effective measures against pests which range over a large territory. Here it is worth considering joint action with his neighbours.

For instance in the case of the variegated grasshopper (Zonoce- rus variegatus) preventive measures should be taken in the loca­ tions where the eggs are laid, such as old tree stumps, heaps of uprooted weeds and damp places in general. Eggs are most effec­ tively destroyed by raking them out so that they dry in the sun. Nest sites are comparatively rare, usually one or two per hectare. The key for a successful control is the destruction of all nest sites over a large area by all farmers. One farmer acting alone has little effect, whereas joint action can reduce the succeeding grasshopper population by 70-80 % (132).

22 IV. PESTS IN FIELD AND STORE In this chapter the most common and important pests which cause much damage to crops growing in the field or stored in silos and barns are described.

In order that the methods by which they can be controlled may be better understood the life-cycle of these insects is given in some detail. A picture of the damage they inflict is also given.

The selection of the pests described resulted from two aspects:

1. Restriction to food plants.

2. Availability of information about Natural Crop Protection meth­ ods.

The control measures described for each pest lead to Chapter V, in which curative methods are described in detail. A short mention is also made of preventive measures.

Insects infesting crops fall into five main groups according to the dominant group of host plants. A further section describes the ones which are found mainly in stores.

24 PESTS OF RICE

1. RICE STEM BORERS

Stem or stalk borers are found wherever rice is grown, and are usually present in the greatest numbers at the end of the rainy season. They have increased since it has become the practice to harvest several crops a year because the insects have a constant supply of food plants.

The following are the most important:

Darkheaded rice stem borer - Chilo polychrysus Purple stalk borer - Sesamia inferens Striped rice stem borer - Chilo suppressalis White paddy stem borer - Scirpophaga innotata Yellow paddy stem borer - Scirpophaga incertulas

Host Plants

primary: Rice secondary: Maize, sugar-cane, millet, wildgrasses.

Distribution

Principally on the Indian subcontinent and in Southeast Asia.

Life-Cycle

The development cycle of all the stem borers is similar and one description will serve. The adult female moth lays about 200 eggs on the leaves or sheaths of the rice plant. The caterpillars hatch after 5-10 days and begin to feed on the leaves. Some days later they bore into the stalk where they feed on the pith. The dark headed rice stem borer is particularly fond of feeding on the stalk joints so that they weaken and break. The larval stage lasts from 28-35 days. Pupation takes place in the lower regions of the stalk, although it can happen in the ground if the caterpillars have travelled that far.

25 PURPLE STALK BORER (Sesamia inferens) STRIPED RICE STEM BORER (Chilo suppressalis)

YELLOW PADDY STEM BORER (Scirpophaga incertul Damage Pattern

The damage is caused by the caterpillars feeding inside the stalks which disrupts the flow of water and nourishment to the plant. The weakened stem thus easily breaks off. Stem borers be­ come particularly numerous in areas where there are several har­ vests a year and infestations can be especially high when the young rice plants are planted too late (48).

The white and striped varieties bore into the leaf sheath and make their way to the growing point which they destroy, producing the 'dead-heart-effect1. As soon as the plant begins to weaken the larvae seek a new food source and in this way inflict a great deal of damage. Young plants are particularly prone to the dead-heart-effect. If the plants are infested after the ears have begun to form they produce only sterile, whitish panicles (White heads).

Control Measures

Once stem borers have disappeared inside the rice stalk it is difficult to treat them effectively because sprays don't reach them. Preventive measures must therefore play the greater role. These are:

* The use of early ripening varieties (67).

* The use of resistant varieties.

* Simultaneous planting.

* Destruction of eggs in the seedbeds (54).

* As a rule, the greater the distance between the plants the greater the infestation.

* The use of light traps (67) p. 133 At the time of the new moon catches are particularly high.

* Spraying with plant preparations: - Neem (52) p. 94 - Persian Lilac (52) p. 94 - Tobacco p. Ill - Cow urine (112) p. 124

28 GRIST suggests that the best time for spraying (although with synthetic pesticides) is about a month before the rice begins to flower, which is also the time when the infestation is at its highest. Several applications may be necessary (54). FRÖHLICH (48) maintains that the best time for treatment is when the adults are in active flight and the young caterpillars are emerging.

* In the case of heavy infestations the rice should be cut very close to the ground. Most of the larvae and pupae will be re­ moved with the straw which can then be grazed or burnt (54).

* Deep ploughing of the stubble immediately after the harvest pre­ vents the development of the adult insect.

RICE HOPPERS

Rice hoppers not only devour rice plants as food, but also in­ flict great damage because they are carriers of destructive virus diseases.

The most important species are:

Brown rice plant hopper Nilaparvata lugens Green rice leaf hopper Nephotettix nigropictus Whitebacked rice plant hopper Sogatella furcifera Zigzag rice leaf hopper Recilia dorsalis

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** Control Measures

* Crop rotation The spread of the brown rice plant hopper has been due above all to the unbroken planting of irrigated rice (89).

* A film of kerosene can be added to the water in seed beds. The young plants are then shaken, whereupon the pests fall into the water and die (36).

* Plant early.

* Control the weeds because many types of wildgrasses are also host plants.

* Use light traps to observe the beginning of the infestation as well as to~catch the hoppers (67) p. 133

* Spraying with plant preparations: - Derris (55) p. 86 - Neem (52) p. 94 - Pyrethrum (55) p. 99 - Soap-solution (55) p. 140

* lise tobacco dust (55).

33 PESTS OF MAIZE

AMERICAN BOLLWORM Heliothis armigera, Fam. Noctuidae

Host Plants

Maize, sorghum, beans, cotton, tobacco, tomatoes, legumes, various vegetables, sunflowers.

Distribution

Throughout the tropics and sub-tropics and the temperate zones of Europe and Asia. Despite its name it is not found on the Ameri­ can continent. There the related species Heliothis zea and H. vi- rescens are common.

Life-Cycle

Round, yellow-brown eggs (1000-1500 per female) are laid singly on young buds, stalks or fruit. In the case of maize this coin­ cides with the flowering period. Stout caterpillers, 3-4 cm long, hatch in 2-4 days with typical wavy and pale longitutional stripes on a yellow to dark green background. The larvae bore into the young maize cobs and feed there. After 14-30 days they make their way to the ground where they pupate and after a further 14 days (at the earliest) the adult brown moths emerge to begin a new life cycle. If the weather is cool the pupating stage is prolonged.

Damage Pattern

The caterpillers bore into the young maize cobs when they are in milk ripe condition. It is characteristic that only the foreparts are in the cobs, the hind parts remaining outside. When they attack other food plants they bore into a suitable part of the fruit. Secondary fungus infections often occur after an infestation of the bollworm.

34 Control Measures

* Avoid continuous maize cropping. Crop rotation is recommended (20).

* Plant early.

* The host plants should be inspected regularly. In the case of maize and sorghum, particularly when they are in a milk ripe condition.

* Introduce light traps (126), p. 133 Eggs are laid when the maize is in flower. To catch the moths of the bollworm the light traps should be set up just before this

35 ARMY WORMS Spodoptera spp., Fam. Noctuidae

Army worms are the caterpillars of a number of different moths of the genus Spodoptera. Most of them embark on migratory flights as moths and are well known for their sudden appearances.

The flight of the African army worm (Spodoptera exempta) is connected to the prevailing trade winds and the onset of the rainy season. Periodically their arrival coincides with a supply of young food plants and the huge numbers of ensuing, simultaneously-born caterpillars possess in their young stage a swarming instinct. As soon as they have devoured one field they move like an army to the next, and hence their name.

Favourable conditions for an outbreak occur when high night temperatures and late precipitations coincide with a supply of young tender grass or corn. According to ALLAM outbreaks of army worms are connected with a state of imbalance in the ecosystem and a reduction in the population of their natural enemies (54).

AFRICAN ARMYWORM (Spodoptera exempta)

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38 Control Measures

* In endangered areas at the time of probable outbreaks it is most important to keep a careful lookout. .

* VAN HUIS reports from Nicaragua that Spodoptera frugiperda is present in reduced numbers when maize is grown in conjunction with beans (154).

* Nitrogen fertilizer has an influence on the probability of an outbreak. In Japan, fields with high applications of nitrogen prove to be more susceptible to army worms (54).

* Army worm traps can be dug (74), p. 135

* Use army worm repellent (10), p. 140

* Use plant preparation: - Neem (52), p. 94 - Pyrethrum (126), p. 99 - Tobacco (126), p. Ill

* Where possible flood a field for two or three days (54).

* Introduce light traps in endangered areas in time to forecast a possible outbreak and reduce future development (126, 21), p. 133

CAREFUL OBSERVATION AND QUICK ACTION ARE CRUCIAL !

BLACK MAIZE BEETLE Heteronychus spp. (H. arator, H. licas, H. consimilis), Fam. Scarabaeidae

Host Plants

primary: Maize and wheat, secondary: Sugar cane, other cereals, yams, tobacco, vegetables and wildgrasses.

39 Distribution

H. arator is found in Southern Africa, Madagascar, Australia and New Zealand. H. licas is found in tropical Africa, Nigeria, Zaire, Swaziland, East Africa, Zimbabwe, South Africa. H. consimi- lis is encountered only in East Africa.

Life-Cycle

The eggs, about 50 per female, are laid in the ground about 1 cm deep near the host plant. The caterpillars hatch after about 10 days and have a soft, fleshy, C-shaped body about 35 mm long. Their food is the organic debris to be found in the ground and root hairs. After a long larva and pupa stage, the adult beetle emerges. It is black, roundish and 15-20 mm long, and as a rule there are only one or two generations a year. After a week the beetles are sexually mature. They live for about 120 days.

Damage Pattern

Plants suffer through the adult beetles who feed on them at ground level, or eat through the young stems below the earth. A single beetle can eat through several plants in a row. When the growing point is affected the 'dead-heart-effect' ensues. Damage by the larvae is comparatively light. Severe feeding at the roots can however, lead to loss of nutrients and a withering of the plant.

Control Measures

* Introduce light traps (126), p. 133 According to RANKIN these are an ideal solution. In Zambia more than 3000 beetles were caught in a single night with 10 light traps. These were arranged in triangular patterns 100 m apart.

* Use a tobacco spray (126), p. Ill The spray should be used in the late evening and aimed at the point where the plant emerges from the ground.

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41 Damage Patterns

Young caterpillars of Busseola fusca and Chilo partellus leave typical holes and 'windows' in the leaves due to their feeding and mining activity.

When the infestation is early and heavy the growing point can be damaged by feeding larvae (dead-heart-effect). The plants then become stunted and produce only small maize cobs. Feeding also affects the pith of the plant and disrupts the nutrient and water supply. This weakens the plant still further.

PINK STALK BORER (Sesamia calamistis)

42 Control Measures

* Use resistant varieties.

* Where possible plant simultaneously over a large area.

* Grow in conjunction with legumes. A maize-cowpea mixture reduces the incidence of Busseola fusca and Sesamia calamistis.

* Use the system of crop rotation.

* Introduce light traps before the eggs are laid, i.e. shortly be­ fore the female moths embark on their flight, which is usually before the maize flowers, p. 133

* Once the maize has been infested the following preparations can be used: - Garlic, p. 89 - Neem (1), p. 94 - Pyrethrum (11), p. 99 - Ryania (1), p. 106 - Tobacco (126), p. Ill - Cow urine (115), p. 124

The timing of the spraying is crucial for the effectiveness of the treatment. Because the young larvae rest on the leaves and in the sheaths before they bore into the stalk, it is essential to spray them at this time, because it is then they are at their most vulnerable. It is also important to ensure that sufficient spray enters the leaf sheaths (48).

* Field hygiene. After a severe outbreak the stubble should be either ploughed in deep or burnt so as to kill any remaining larvae (83).

43 PESTS OF LEGUMES

BEAN FLY Melanagromyza phaseoli, Fam. Agromyzidae

Host Plants

Beans of all kinds, including Phaseolus, Vicia and Glycine spp. Other legumes are also attacked.

Distribution

The Indian sub-continent, Southeast-Asia, East-Australia, parts of East and Southern Africa.

Life-Cycle

As soon as the first leaves have appeared the bean fly lays its eggs on the upper surface of the leaf. They are white, oval, about 1 mm long and are laid singly in small cavities concentrated along the leaf veins where the leaf joins the stem. The larva, a small white maggot, burrows into the leaf and forms a bow-shaped track. Finally the maggot burrows into the stem and travels downwards to the neck of the root where it feeds just above the ground level. There pupation takes place, although sometimes it occurs in the cracked parts of the stem. The adult insect emerges as a 2 mm long glistening black fly. The whole life-cycle can last as little as two or three weeks.

Damage Pattern

Infested plants become yellow and show a stunted growth. The nutrient flow is diminished due to the destruction of the stem pith. The stems thicken directly above the ground and often break off. Many plants die. Surviving plants produce very few pods which are often empty or contain very small seeds. Damage is particular­ ly high in the dry season.

44 egg-laying bean fly Control Measures

* A good measure of control can always be achieved by planting at an appropriate season (142).

* Overlapping, successive plantings of beans should always be avoided. It is better to rotate the crops.

* Spray with a tobacco preparation (18), p. Ill Two pre-flowering sprayings are recommended. (When synthetic insecticides are used it usually is carried out 2 and 12 days after germination).

* After an outbreak all plant residues should be removed after the harvest and burnt (26).

MEXICAN BEAN BEETLE Epilachna varivestis Muls., Fam. Coccinellidae

Host Plants

primary: Legumes (principally common beans), limabeans, cow- peas, soyabeans, secondary: Maize, cucurbits, potatoes, eggplants.

Distribution

From Panama to Canada, Africa and Asia.

Life-Cycle

Elliptical, pale yellow eggs are laid in groups on the underside of the leaf. After 4-5 days oval-shaped yellow larvae hatch out. Each body segment is covered with 4-6-branched yellow hairs with black tips. The larvae grow to about 8 mm long and pupate on the leaf. The adult beetles are oval in shape and from 6-8 mm long.

46 They are coloured reddish-yellow to yellowish-brown with 16 black spots. The Mexican bean beetle is a ladybird and it is one of the rare leaf-eating members of this family. The females lay about 1500 eggs and under good conditions the life-cycle lasts from 35-40 days.

Damage Pattern

Both larvae and beetles cause severe feeding damage. The larvae rupture the undersides of the leaves to imbibe the sap, but the upper epidermis remains intact and the leaves assume a bizarre pattern of translucent patches. The beetles on the other hand de­ vour all the leaf between the ribs, but in severe cases will con­ sume the stems and pods of legumes as well. Mexican bean beetles are particularly harmful to young plants before they have flowered (30).

/

Control Measures

* Early ripening varieties often suffer less damage.

* After an infestation crop residues should be ploughed in to a depth of at least 15 cm. It is important that all the plant mate­ rial is completely covered.

47 * Use plant preparations: - Derris, p. 86 - Garlic (106), p. 89 - Neem (52), p. 94 - Pyrethrum (126), p. 99 - Yam bean (52), p. 120

Applications should take place before the eggs are laid (19).

POTATO JASSIDS Empoasca fabae, Fam. Cicadellidae

Host Plants

Legumes (principally common beans), potatoes, cucurbits, sweet potatoes, okra, tomatoes and many others.

Distribution

North-America (East-USA), Central- and South America.

Life-Cycle

Greenish, banana-shaped eggs are sunk into the stalks and ribs on the underside of the leaf. After about 9 days they hatch and take from 14-18 days to go through five larval (nymphal) stages. When they are fully grown they are about 2 mm long, yellowish-green and froglike. The adult insect is pale green with a thin body about 2,5 mm long. When they are disturbed they jump or fly or they scuttle sideways like the nymphs. A female lays up to about 200 eggs (61).

48 Damage Pattern

Both nymphs and adults imbibe sap from the underside of the leaf and from the stems. The leaves of infested plants become yellow at first and gradually the edges turn reddish-brown and curl under. As a result the plant becomes stunted, shrivelled and may die. Young plants and seedlings are particularly at risk (19).

Control Measures

* Planting during the rainy season (30).

* Plant resistant varieties, such as those with dense hairy leaves which prevent the jassid from depositing its eggs (142).

* Mulching (30).

* Use sprays: - Pyrethrum (19), p. 99 - Tobacco (19), p. Ill

* Use dusts: - Derris (19), p. 86 - Sabadilla (19), p. 107 - Tobacco (19), p. Ill

The best time for treatment against E. fabae is during the first month of growth when the plants are about 10 cm high. This is the time when the females are laying their eggs (161).

49 PESTS OF VEGETABLES

APHIDS All species, Fam. Aphididae

Since all aphids have similar life-cycles and require similar con­ trol methods, they are described collectively.

Host Plants

Legumes, cucurbits, nightshade family, wildgrasses, citrus, and many more.

Life-Cycle

Aphids are soft, pear-shaped, polyphagous sap imbibers, at big­ gest 4 mm long. The mouth parts consist of a needle sharp stiletto to puncture into the plant and suck out the sap. Aphids colonize preferably young leaves and shoots.

Reproduction is both sexual and parthenogenetic. An adult can produce 2-20 offspring per day and under favourable conditions a whole life-cycle can last as little as two weeks. There are both winged and wingless types, the winged form developing when the population density becomes too high.

Damage Pattern

Aphids cause direct and indirect damage:

Direct damage occurs through the imbibing of sap. A simultaneous higher rate of plant respiration is probably attributable to the in­ jection of spittle by the aphid. Deformation of the leaves, reduced growth, and in the case of legumes, a smaller nitrogen nodule, are direct results. Aphids secret honeydew and this results in a fungus growth which affects photosynthèses.

Indirect damage is caused by the transmission by aphids of vi­ rus disease, e.g. bean mosaic virus, rosette virus and cucumber mosaic virus.

50 Control Measures

* Encourage natural enemies by enhancing diversity.

* Use nitrogen-fertilizers with discretion, but apply organic manures liberally.

* Use sprays: - Annona (13), p. 81 - Chilli (43), p. 84 - Derris (37), p. 86 - Garlic (124), p. 89 - Neem (52), p. 94 - Quassia (133), p. 103 - Tobacco (126), p. Ill - Yam bean (13), p. 120 - Urine (115, 127), p. 124 - Flour preparation (125), p. 139 - Soap solution, p. 140

51 CUTWORMS Agrotis ypsilon (greasy cutworm), Agrotis segetum (turnip moth) Fam. Noctuidae

Host Plants

primary: Vegetables and roots, secondary: Maize, tobacco, coffee.

Distribution

European continent, Africa and Indian sub-continent.

Life-Cycle

The eggs are laid on the stalks of the host plant or in the ground nearby. A moth lays between 1000 and 1300 eggs and the caterpillars hatch in 10-14 days, feeding on the leaves of the host plant for the first one or two weeks. Thereafter they move into the ground where they settle close by a host plant. When fully grown they are greyish brown and 4-5 cm long. Pupation takes place in the ground. This stage lasts 10-30 days. The turnip moth has a wingspan of 3-4 cm and the forewings are grey-brown with dark brown or black kidney-shaped markings. The rear wings are almost white although those of the male are darker. The moths of the greasy cutworm are larger with a grey body and grey forewings with dark brown or black markings. The rear wings are almost white with darker edgings.

Damage Pattern

During the day the caterpillars remain in the ground where they feed on the roots of the host plant (48). At night they emerge and feed on the stems of young plants which fall over as a result and entire rows can be destroyed. They also severely damage root and tuber crops.

52

Control Measures

It is advisable to control the caterpillars when they are young and are feeding on the leaves. Once they have retired into the ground it is much more difficult to treat them effectively.

* Ploughing a month before sowing turns the caterpillars or pupae up to the surface where they shrivel in the sun or are eaten by birds (161).

* Keeping down weeds early in the year reduces the egg laying sites (161).

* Treat the seed bed with wood ash or a mixture of wood ash and chalk (36).

* Nails or splinters of wood can be set in the ground near each stalk of the host plant. This causes the caterpillars to avoid such host plants to a certain degree (161).

* Introduce light traps, p. 133

* Put out cutworm bait, p. 129

* Use sprays: - Derris (35), p. 86 - Pyrethrum (126), p. 99 - Tobacco (126), p. Ill this should not be used where a member of the Solanaceae family is being grown because of the danger of transmitting a virus disease.

Sprays should be used on young plants and directed particularly at the point where they emerge from the ground.

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57 Control Measures

* Encourage natural enemies by maintaining natural surroundings with plenty of breeding places.

* Mixed cultivation can help reducing infestation: For instance tomatoes planted between the rows of cabbages re­ pel the diamondback moth (Plutella xylostella).

* Introduce light traps (126), p. 133

* Use sprays: - Annona (52), p. 81 - Derris (37), p. 86 - Mammey (52), p. 92 - Neem (52), p. 94 - Quassia (35), p. 103 - Pyrethrum (126), p. 99 - Tobacco (126), p. Ill - Yam beans (52), p. 120

MITES Tetranychus spp., Fam. Tetranychidae

Host Plants

Cucurbits, legumes, nightshade family, sweet potatoes, cassava, citrus, tree tomato, taro and others.

Distribution

Tropical, subtropical and temperate zones.

Life-Cycle

Mites are tiny, spider-like creatures. Many are bright red in colour, but sometimes they are green or orange. Yellowish eggs are

58 laid singly on the underside of the leaf or under the silk web woven by the adults. After 4-7 days the larvae hatch and pupate after another 6-10 days. A fully grown mite lives for about 3 weeks and in this time lays about 200 eggs.

Damage pattern

At all stages of development mites imbibe sap from between the leaf veins. These places show up as yellowish spots. Later the leaf turns brown and becomes covered with a silvery coating. In particularly severe cases the leaf shrivels, the development of new leaves and buds is inhibited and the plant gradually dies. Infe­ station by mites is heaviest in the dry season.

Control Measures

* Encourage natural enemies The role of mites as pest has increased with the more intensive use of synthetic pesticides since these have reduced the number of natural enemies (118).

* Plant the most vulnerable vegetables in the rainy season where possible.

* Choose resistant varieties.

* Use nitrogen-fertilizers sparingly (161).

* Use sprays: - Garlic (125), p. 89 - Neem (52), p. 94 - Pyrethrum, p. 99 - Urine (127), p. 124 - Flour preparation (125), p. 139 - Kerosene-soap emulsion (146), p. 140 - Soap solution (74), p. 140

59 THRIPS Thrips spp., Fam. Thripidae

Host Plants

The onion thrips infest a whole range of vegetables such as to­ matoes, collards, leeks, garlic and peas, as well as onions. The bean thrips feed not only on beans, but on peas, peanuts, coffee, avocado and many others.

Distibution

The onion thrips is most widely distributed and is found every­ where except West Africa.

Life-Cycle

Onion thrips eggs are laid in incisions in the epidermis of the leaves and stems of young plants. They are white and hatch in 4-10 days. Both the larvae (nymphs) and the adult insects pierce the epidermis of the leaves and imbibe the sap. Pupation takes place in the ground. The emerging insects are very small, only about 1 mm long, yellow brown with dark cross stripes on the body. The entire life-cycle lasts only three weeks or so and there­ fore 5-10 generations a year can result.

Damage Pattern

Typical damage pattern is a silvery flecked leaf surface which in severe cases turns brown. Onion leaves often become deformed and die. A further sign of thrips infestation are small black spots on the leaves, the excrements of the insect.

Indirect damage results from virus diseases which are carried by thrips. The most common are cassava mosaic, cotton leaf curl, tobacco leaf curl and sweet potato virus B.

60 ONION THRIPS (Thrips tabaci)

Control Measures

* Mulching reduces thrips infestation considerably (61).

* Deep ploughing after the harvest to bury the pupae (48).

* Stubble and other harvest remains should be burnt to reduce future populations (48).

* Use sprays: - A preparation of the leaves of Calotropis procera boiled with soap (36). - Garlic (125), p. 89 - Neem (36, 52), p. 94 - Pyrethrum (48), p. 99 - Preparations containing rotenone such as derris, lonchocarpus and tephrosia (161), p. 86

- Tobacco both in spray and dust form (36), p. Ill

- Soap solution, p. 140

Because eggs and pupae in the ground are not affected by sprays it is recommended that the treatment should be repeated when infestations are heavy.

61 WHITE FLY Bemisia tabaci, Fam. Aleyrodidae

Host Plants

Tobacco, beans, cucurbits, potatoes, eggplants, sunflowers, okra, cotton.

Distribution

Widely distributed throughout the tropics, subtropics and also in the temperate zones.

Life-Cycle

Tiny pear-shaped eggs hang vertically from the underside of the leaf. After about seven days the nymphs (larvae) hatch and begin to imbibe sap. They go through several nymphal stages all of which are greenish white and oval. In 2-4 weeks the adult fly emerges, about 1 mm long with white wings and a body powdered with a white floury secretion. Each female lays about 100 eggs.

Damage Pattern

An indescriminate feeder which above all likes dry conditions and appears in the dry season. With the onset of rain it largely disappears. It is also a widely prevalent greenhouse pest. Since the introduction of synthetic insecticides the white fly has deve­ loped into a major secondary pest.

The host plant suffers in several ways: * It weakens due to the removal of sap. * The insects exude honeydew resulting in the development of a black fungus which inhibits photosynthesis. * White flies are carriers of virus infections, e.g. cassava mosaic and cotton leaf curl. These result in deformed twisted leaves with a yellow colour.

62 colony of white flies on the underside of leaf

Control Measures

* Because of the spread of virus diseases it is important to use infection free seeds or seedlings.

* Plant resistant varieties (20).

* Encourage natural enemies (35).

* Use traps in greenhouse, p. 129

* Use sprays: - Garlic (35), p. 89 - Pyrethrum, p. 99 - Ryania (52, 161), p. 106 - Sabadilla (52), p. 107 - Tobacco (161), p. Ill - Kerosene-soap emulsion (74), p. 140 (This is not specially mentioned for white flies, but for piercing and sucking insects in general.)

63 PESTS OF FRUITS

FALSE CODLING MOTH Cryptophlebia leucotreta, Fam. Tortricidae

Host Plants

primary: Citrus fruits and cotton, secondary: Maize and a variety of wild and cultivated fruits.

Distribution

In Africa from Ethiopia to Senegal and southwards to the Cape. In Tanzania it is a very troublesome pest of citrus.

Life-Cycle

Flattish, oval and whitish eggs are laid singly on ripening fruit, usually up to about 8 per specimen. After 3-6 days the larvae emerge. They are whitish pink in colour and grow to about 15 mm long. At first they travel around the outside of the fruit, but later bore their way inside and move about to feed. Towards the end of the larva phase they make their way down to the ground and pupate in a cocoon made of silk and earth. After 8-12 days a little brown moth emerges with a wingspan of about 16 mm. The females live for about a week and lay 100-400 eggs.

Damage Pattern

The entrance hole which the young larvae have bored into the fruit, leaves a yellow spot on the skin. The flesh of the fruit where the larvae are feeding becomes contaminated with their ex­ crements. Infected fruit falls prematurely. Secondary infections due to fungus can also occur.

64 Control Measures

* Keep a careful lookout for an outbreak.

* Introduce fruit fly traps (126), p. 129

* Use botanical sprays: - Cockroach plant (Haplophyton cimicidum) (133), p. 118 - Garlic (8), p. 89 - Pyrethrum (126), p. 99 - Tobacco (126), p. Ill

A favourable time to spray is when the larvae wander around on top of the fruit before they burrow their way inside.

* Fallen infested fruit should be collected twice a week, transferred to a barrel and covered with water to which a cupful of diesel oil is added. The fruit should remain immersed for at least a week (some sources mention three weeks) to ensure that none of the larvae survives (126). The fruit can then be composted.

* Fallen infested fruit can also be buried 50-100 cm deep in the ground (20).

65 66 damaged fruit larva pupa

Control Measures

* It is important to keep down aphids and other honeydew produ­ cing insects because fruit flies are attracted by honeydew.

* Introduce fruit fly traps (126), p. 129

* Collecting and removal of prematurely fallen fruits (see false codling moth).

* Use sprays: - Cockroach plant (Haplophyton cimicidum) (52), p. 118 - Derris (52), p. 86 - Neem (139), p. 94 - Ryania (52), p. 106 - Sweet flag (as bait) (52), p. Ill

68 PESTS OF STORAGE

BEAN BRUCHID Acanthoscelides obtectus, Fam. Bruchidae

Host Plants

primary: Beans of all kinds, secondary: Other legumes

Distribution

The bean bruchid originated in Central and South America, but is now found all over the world with the exception of Asia.

Life-Cycle

Creamy-white pointed eggs are laid on the ripe pods in the field (about 80 per female). The larvae which are whitish or pale yellow, are about 6 mm long, and they bore into the beans inside the pods and feed. From here on their life-cycle is similar to that of Callosobruchus. The larvae pupate inside the beans and the adult bruchid emerges through the prepared exit hole. Their pre­ sence is easily recognizable by the small window-like hole.

Damage Pattern

Infested beans usually exhibit several holes. One or two holes in a bean are sufficient to prevent it from germinating. This is due to feeding on the seed cotyledons (62).

Control Measures

See Callosobruchus

69 BEAN BRUCHID (Acanthoscelides obtectus)

COWPEA BRUCHIDS Callosobruchus chinensis (Adzuki Bean Beetle), Callosobruchus maculatus (Cowpea beetle), Fam. Bruchidae

Host Plants

primary: Adzuki beans or cowpeas secondary: Soya beans and other legumes

Distribution

Throughout the warm regions of the world.

Life-Cycle

An infestation of Callosobruchus can occur in either field or storehouse. In the field the eggs are laid on the outside of the pods and in store they are laid directly onto the seeds and fastened in place with a secreted fluid. After hatching the larvae bore into the seed cotyledons on which they feed. Hollowing them out produces a 'window-effect'. Before to pupate in the seed the larvae prepare the exit holes. The adult insect is a little brown beetle which lives for 4-5 weeks.

70 Damage Pattern

The larvae bore into the seeds and hollow them out by feeding. Infestation usually occurs in store. But as the adults can fly up to half a mile they can also infest adjacent fields.

ADZUKI BEAN BEETLE COWPEA BEETLE (Callosobruchus chinensis) (Callosobruchus maculatus)

Control Measures

* Susceptible crops should be planted at least half a mile from storehouses.

* Early harvesting. Bean weevils infest legumes in the field only when they are al­ most dry. Early harvesting therefore reduces the probability of introducing beetles into the store (86).

* The store should be dry and cool.

* Treat the beans with vegetable oils.

* Use preparations made from plants with insecticidal properties to protect beans and other legumes in store: - Cassia nigricans (85), p. 147 - Chilli, p. 146 - Dennettia oil (69), p. 118 - Eucalyptus (3), p. 118 - Hyptis spicigera (85), p. 147 - Neem oil (119), p. 151 - Spearmint (101), p. 157 - Sweet flag (160), p. 158

* Use wood ash, p. 165

* Use sand, p. 165

71 KHAPRA BEETLE Trogoderma granarium, Fam. Dermestidae

Host Plants

primary: Cereals and peanuts secondary: Legumes, herbs and spices, manufactured products of grain, legumes, oilseeds etc.

Distribution

Almost worldwide with the exception of eastern and southern Africa, principally in hot dry climates.

Life-Cycle

Eggs are laid in stored products and the larvae have the ability to develop to the insect stage in as litte as two weeks if it is warm and plenty of food is available. If however, the store is empty they can survive in an inactive state in cracks and cre­ vices for as long as a year. The adults are wingless, black-brown beetles 2-3 mm long. Under optimum conditions the life-cycle can last for only three weeks, although it can be of 2-3 year duration.

Khapra beetles are mostly spread via human activities.

Damage Pattern

The larvae are the principal source of damage by boring into and eating grain. In the absence of food they become inactive and can survive for a year or longer.

Control Measures

* Store in cool places. At temperatures lower than 20°C the larvae do not develop.

* Use insecticidal plants

- Neem (23), p. 151 - Sweet flag (52), p. 158

72 KHAPRA BEETLE (Trogoderma granarium) larva

LESSER GRAIN BORER Rhizopertha dominica, Fam. Bostrychidae

Host Plants

primary: Grain in store secondary: Cassava, grain and flour or meal products

Distribution

Worldwide in all warm regions including southern Europe.

Life-Cycle

The eggs are laid between the grains of corn or in crevices in the storehouse walls. Rough surfaces are preferred to smooth. The larvae have legs and can move easily. They bore into the grains if they have a moisture content of more then 8 % and there they pupate. The adult beetles are 2-3 mm long and have a cylindrical body. They are long lived.

73 Damage Pattern

Both larvae and beetles cause tremendous damage by boring through the stored produce causing characteristic tunnels. Infesta­ tion does not occur before harvest. The lesser grain borer is a typical pest of the hot tropical areas.

(Rhizopertha dominica) larva inside grain

Control Measures

* Unripe grain should never be stored. Its softness and the loose­ ness of the husk make it particularly attractive (54). * Damaging the grain should be avoided. Larvae will take advan­ tage of small cracks to bore into grain, and beetles will infest grain which appears intact to the naked eye (54).

* Use neem powder or oil (52), p. 151

* Use Sweet flag powder or oil (52), p. 158

* Heat treatment (56), p. 140

74 MAIZE WEEVIL Sitophilus zeamais, Fam. Curculionidae

Host Plants

primary: Maize secondary: Sorghum, rice and other stored grains

Distribution

Throughout the tropics and subtropics as well as in southern Europe.

Life-Cycle

The life-cycle is similar to that of the rice weevil. A female lays between 300-400 eggs. The adult weevils live for about 5 months and are very good flyers. In the hot season one generation can succeed another in as little as 5 weeks.

Damage Pattern

A small tunnel is bored to the centre of the maize. Typical are the round exit holes on the grain surface.

75 Control Measures

* Storehouses should be situated as far away as possible from the. fields where the maize is grown. Maize weevils can fly long dis­ tances and will often infest a crop while it is still in the field.

* Use goat dung sprays, p. 125

* Use insecticidal plants

- Crotalaria (49, 65), p. 118 - Neem (52), p. 151

RICE WEEVIL Sitophilus oryzae, Fam. Curculionidae

Host Plants

primary: Rice secondary: Maize and other stored grains.

Distribution

Throughout the tropics and subtropics as well as in southern Europe.

Life-Cycle

The female bores a small hole in the grain in which to lay her oval white eggs and seals them in with a secretion. The larvae hatch and make their way to the germ of the grain where they develop further until they are about 4 mm long. Small 'windows' in the grain are typical for an infestation. After pupation the weevils emerge through the preprepared exit holes.

76 Damage Pattern

Damage is caused by the larvae feeding on the grain and often leaving it completely hollow. Sometimes eggs are laid in the grain before it is harvested and the larvae develop later in the store.

• Control Measures

* Choose resistant varieties.

* A balanced fertilization which considers the silicon demand of rice will strengthen the plant (54).

* Careful harvesting. Undamaged grain is much less susceptible to infestation.

* Treat grains with vegetable oils.

* Treat grains with wood ash or rice husk ash, p. 165

* Fumigate the store (10), p. 146

* Use plant products with insecticidal properties: - Mammey, p. 92 - Neem, p. 151 - Spearmint, p. 157 - Sweet flag, p. 158 - Turmeric, p. 162

77 POTATO TUBER MOTH Phthorimaea operculella, Fam. Gelechiidae

Host Plants

primary : Potatoes secondary: Tobacco, tomatoes, eggplant and other members of the Solanaceae family.

Distribution

Almost worldwide, although rarely in Asia

Life-Cycle

In the field, small oval eggs are laid on the underside of the leaves, or in store directly on the tubers near the eyes or sprouts. Each female lays 150-200 eggs which hatch in 3-15 days. The larvae mine their way through the leaf veins and gradually reach the stem to travel to the ground. There they pupate in the earth or in heaps of organic material. In store pupation usually takes place outside the tuber, often between sacks in a cocoon. The adult is a small, insignificant moth with narrow fringed wings spanning 15-20 mm. The forewings are grey-brown with dark spots; the rear wings a dirty white.

Damage Pattern

Silvery patches appear on the leaves caused by the mining acti­ vities of the larvae. The leaf-veins, side-stems and stalks are all pitted with holes which interrupt the flow of nutrients and cause the plant to wither. Finally the tubers are bored completely through by the larvae which gives rise to secondary infections by fungi and bacteria.

78 Control Measures

* Mixed cropping with onions, tomatoes, beans, soya beans and maize reduces infestation (32).

* Use botanical repellents in store: - Eucalyptus (34), p. 118 - Lantana camara (32), p. 148 - Muna, p. 148

* Where chemical sprays are used it is usual to repeat the appli­ cations every two weeks after mining activities have been dis­ covered. Plant preparations could be tried as well.

The principal sources which have been used for the description of the forementioned pests are:

20, 26, 30, 54, 61, 67, 126, 142.

79 V. METHODS OF CROP AND STORAGE PROTECTION

80 FIELD CULTIVATIONS

INSECTICIDAL PLANTS

ANNONA - Soursop (Annona muricata), Custard apple (Annona reti­ culata), Sweetsop (Annona squamosa). Fam. Annonaceae

1. General

More than 90 species of small trees and shrubs are known in the Annonaceae family. They occur mostly in tropical America, but some are found also in Asia and Africa. Soursop and custard apple are widely distributed in Central America and the Caribbean, while the sweetsop is commenest in India and Southeast Asia. They do not require special conditions of soil or water, but thrive best in places where there is a clear division between the rainy and dry season, and generally prefer dry sites in which to grow (22). The effective ingredients are in the unripe fruit, and in the seeds, leaves and roots (107). The oil content of the seeds amounts to 42-45 %.

Effective Range

Contact- and stomac poison insecticidal, larvicidal, repellent, antifeedant (52).

Target Insects

Aphids general (13) Brown rice plant hoper Nilaparvata lugens (13) Diamondback Moth Plutella xylostella (59) Chrysanthemum aphid Macrosiphoniella sanborni (59)

81 Grasshoppers general Green bugs general (13) Green rice leaf hopper Nephotettix virescens (13) Potato aphid Macrosiphum euphorbiae (59) Red pumpkin beetle Aulacophora foveicollis (59) Whitebacked rice plant hopper Sogatella furcifera (13)

Annona has not proved effective against the

Saw-toothed grain beetle - Oryzaephilus surinamensis (147)

SWEETSOP (Annona squamosa)

Observations

* The toxic effect of annona sets in slowly , 2-3 days should be allowed. * Laboratory trials have shown that by extracting annona seeds with ether or petroleum ether, the toxicity can be increased 50-100 times. But since laboratory methods are impractical in the field, other locally available and cheap solvents could be tried, like petrol or kerosene. * When pulverising the seeds of A. squamosa, care should be ta­ ken to ensure that the powder does not come into contact with the eyes as this causes great pain (80).

* The custard apple is the most effective of the annonas against insects.

82 SOURSOP (Annona muricata)

2. Methods of Use

Relatively litte information exists on the preparation and use of annona. Wide-ranging laboratory trials have demonstrated its highly effective insecticidal value. Experimentally-inclined farmers could contribute much needed information about this widely distri­ buted plant.

* A 10 % concentration of seed oil produces a 90 % death rate of the bug Urentius echinus within 72 hours. A 5-7 % concentration is still effective, but low concentrations of 1-3 % produce no results.

* Pulverised seeds are used in China and the Philippines against parasites, insects as well as lices, which affect humans.

* A water suspension of the seeds gives a high mortality against Lecanium in West-Africa (68). The writer gives no details regar­ ding quantities.

* An extract of the leaves with ether proves highly successful against the red pumpkin beetle (Aulacophora foveicollis). A di­ luted solution achieves a 91 % death rate (27).

83 CHILLIPEPPER - Capsicum frutescens Fam. Solanaceae

1. General

Chillies are widely distributed in the tropics and subtropics and originate in South America where they were early cultivated. They were introduced to the rest of the world by the Spaniards and the Portuguese. The ripe fruit has insecticidal properties and the ef­ fective substances are highest in the skin and in the seed (47).

Effective Range

Stomac poison insecticidal, repellent, antifeedant, fumigant, viroid (52, 130).

84 Target Organisms

Ants general (152) Aphids general (152) Caterpillars general (161) Colorado beetle Leptinotarsa decemlineata (71) Imported cabbage worm Pieris rapae (161) Rice weevil Sitophilus oryzae (41) Warehouse pests general (52) Cucumber mosaic virus (161) Cucumber ringspot virus (161) Tobacco etch (161) Tobacco mosaic virus (161) Tobacco ringspot virus (161)

2. Methods of Use

* From Kenya good results are reported on the control of aphids in home vegetable gardens. Hot chillipeppers are finely ground, stirred in water and allo­ wed to stand overnight. After filtering through a cloth the solu­ tion is sprayed onto the plants, or if no syringe is available sprinkled with a whisk of twigs or grass (152).

* A similar method is reported from Papua New Guinea where chil- liepepper is used as a repellent. Finely ground chillies are covered with water and soap added, either as flakes or liquid. The mixture is well stirred and sprayed over the affected plants (88).

* Chilli spray preparations are also well known in the Philip­ pines (130): 100 g chillies, water, soap solution: The chillies are finely pulverised in a mortar, vigorously sha­ ken with 1 litre of water and filtered through a cloth. One part of this concentrate is diluted with five parts of soapy water before spraying. It is effective against aphids and many other vegetable pests.

Too strong a concentrate causes burning of the leaves, so the right strength should be found by testing.

Care should be taken because the solution irritates the skin (130).

85 Virus Inhibition

MCKEEN reports that when the young leaves of cowpeas were rubbed with virus-infected sap expressed from chilli leaves the colour change was markedly reduced, mostly there was even none. (The change of colour is regarded as an indicator of a virus in­ fection). When the experiment was repeated with the sap from virus-infected tobacco leaves the cowpea leaves underwent a strong colour change, but when the tobacco sap was mixed with 5 % of chilli sap the number of leaves which changed colour was reduced by 95 %.

The effectiveness of the virus inhibition depends on the host plant. It is probable that members of the same plant family do not work infallibly on one another as virus inhibitors. Further tests showed that the virus-inhibiting ingredient is present in all parts of the chilli plant. However, extracts from the leaves and flowers showed the highest concentration and the roots the lowest.

In practice it is important that chilli sap should be applied as a preventive measure before the virus infection affects the plant. Once the virus has taken hold it cannot be effectively controlled.

This information is all derived from scientific sources. The writer has no results taken from practice in the field (96).

DERRIS - Derris elliptica, D. malaccensis, D. uliginosa Fam. Leguminoseae

1. General

Derris is a small shrub originating in the tropical rain forests of the Malay Archipeligo. It grows in lowland areas and does not thrive at higher altitudes. It is the roots which contain the active substances, mainly rotenone. Grown in the shade D. malaccensis

86 requires a period of 1 1/2 - 2 years for it to produce a worthwhile content of rotenone, but when grown in full sunlight needs only nine months for the roots to develop sufficiently (37). D. elliptica developed after about 26 months the maximum amount of rotenone. Derris can be propagated vegetatively from 50 cm long cuttings when rooting follows after about six weeks (5). The crop is harvested by exposing the shallow roots and cutting off those with a diameter of 2-6 cm since these have the highest rotenone content. Derris thrives on many soils but particularly on loams and clays.

Effective Range

Contact- and stomac poison Insecticidal and repellent (52).

Target Organisms

Adzuki bean beetle Callosobruchus chinensis (71) Army worms Spodoptera litura (37) American bollworm Heliothis armigera (37) Diamondback moth Plutella xylostella (37) Fruit flies Dacus spp. (52) Mediterranean fruit fly Ceratitis capitata (52) Melon aphid Aphis gossypii (37) Crocidolomia binotalis (37) Margaronia indica (37) Crysodeixes chalsites (37)

Derris is also effective against the fungus Pyricularia oryzae (52)

87 Remarks

* Derris is most effective against larvae in the young stages. Caterpillars, aphids and beetles are very vulnerable, but it is not effective against cockroaches.

* Derris is affected by sunlight, oxygen and temperature. After a week in strong sunlight derris dust is no longer effective. In the shade it retains its properties for a fortnight (141).

* Handling derris dust can also cause skin rashes and should therefore be avoided. If derris dust or spray is inhaled over a period it can give rise to a numb feeling in the lips, tongue and throat (141).

* Derris is harmless to bees, but toxic to fish.

2. Methods of Use

Sprays

* Freshly cut roots from 2-6 cm diameter are washed and cut into 5 cm lengths. With a stone or pestle they are pounded together with soap and a little water. Soap facilitates the solubility of the rotenone. When the roots are completely shredded into fibres the liquid is filtered off through a fine cloth. The resulting solution is diluted to the approved strength and used at once.

The following quantities are recommended (37):

1 part soap : 4 parts roots : 225 parts water

* When finely powdered derris dust is obtainable the following proportions should be used for an extract (5):

100 litres water : 500 g neutral soap : 1 kg derris

* A preparation which is highly effective against apple aphids can be made by stirring 2,5 kg derris dust into 400 litres of soap solution (5).

88 Powder preparations

* In trials pulverised derris roots containing about 5 % rotenone were diluted with talc in the proportions of 1 : 5, 1 :10 and 1 : 20. These preparations were dusted at the rate of 30 kg/ha over cabbage plants which were infested with the larvae of the Imported cabbage worm and Cabbage loopers. Three applications were given over a period of two weeks. The dilution of 1 : 5 produced the least feeding damage (109).

* In another trial the following mixture was dusted over cabbages just as they were beginning to head:

30 % pyrethrum (1,16 % pyrethrin) 20 % derris dust (4 % rotenone) 50 % alumina as a carrying agent

Two applications were given at an interval of 7 days. A week later the plants were examined with the following results:

- On 50 plants a total of only 4 caterpillars were discovered. - Large numbers of flea beetles were killed and many plants had 50-100 dead flea beetles on the outer leaves. - The death rate among aphids was unstatisfactorily low. - Thrips, which inhabit the underside of the outer leaves, were not reduced (57).

GARLIC - Allium sativum Fam. Liliaceae

1. General

Garlic is a cosmopolitan plant which grows in temperate zones as well as in the tropics and subtropics. It probably originated in Central Asia whence it spread to the Mediterranean, around whose shores it still finds its greatest use in the kitchen (122).

89 It is much cultivated and is easy to grow in field, garden or backyard. For use as an insecticide it should not be grown with mineral fertilizers since it has been established that heavy doses of fertilizer reduce the concentration of the effective substances.

Effective Range

Insecticidal, repellent, antifeedant, bactericidal, fungicidal, nematocidal and effective against ticks (52).

90 Target Organisms

Aphids general (8) Army worms Spodoptera litura Colorado Beetle Leptinotarsa decemlineata (53) False codling moth Cryptophlebia leucotreta (8) Khapra beetle Trogoderma granarium (16) Mexican bean beetle Epilachna varivestis (106) Imported cabbage worm Pieris rapae (53) Wire worms general (8)

Garlic has also been found to be effectiv against fungus such as mildew and beanrust.

Remarks

* Some gardeners in Germany have long made a garlic solution in water to use against pests. According to them it should be applied immediately after the preparation so that the volatile oils do not escape into the atmosphere before to exert their effects on the plants (ILLMANN, pers.comm.).

* Laboratory trials indicated that an extract of garlic reduced feeding by older larvae less than by younger larvae (106).

2. Methods of Use

* 100 g garlic cloves, 0,5 litres of water, 10 gm soap, 2 tea spoons mineral oil. Steep the finely grated garlic for 24 hours in the mineral oil. Dissolve the soap in the water, mix with the infusion of garlic and mineral oil., stir well together and filter through a fine cloth. Before use this solution is diluted with 20 parts of water. It is effective against the most common pests, but different strengths should be experimented with regarding specific insects. (9, 161).

* Steep 3 finely grounded garlic bulbs for 2 days in liquid para- fin and then stir well with a large spoonful of soap flakes and 10 litres of water. This preparation is effective against a wide range of insect pests (44).

91 * The following preparation is successful against caterpillars in fruit trees : 2 finely grated garlic bulbs and two teaspoon chillipeppers are stirred into 4 litres of hot water in which a nut sized piece of soap has been dissolved (161).

MAMMEY - Mammea americana Fam. Guttiferaceae

1. General

This tree grows to a height of 20 m and originated in the Carib­ bean and in northern South America. In the meantime it is also spread in the tropical regions of Africa and Asia. It thrives up to 1000 m and there are two harvests a year and each tree yields 300-400 fruits.

The insecticidal plant part is above all the ripe seed. Leaves and bark possess only a low insecticidal action.

Effective Range

Contact- and stomach poison, insecticidal, repellent, nematicidal and effective against ticks.

Target Insects

Aphids general (70) Diamondback moth Plutella xylostella (117) Cucumber beetle Diabrotica bivittata (70) Imported cabbage worm Pieris rapae (70) Melon worm Diaphania hyalinata (117) Mites general Rice weevil Sitophilus oryzae (70) Ascia monuste (117) Cerotoma ruficornis (117)

92 Remarks

* After 4 days of sun, wind and dew mammey powder was still an effective poison (117).

* In the West Indies the resin of the mammey apple tree is used against sand flies (14).

2. Methods of Use

Powder made from mammey apple seeds can be used either as a dusting agent or in solution as a spray. Besides water solutions, preparations may be made with kerosene which can be used effec­ tively against household vermin.

* Mammey powder can be dusted onto cabbages against caterpillars of the diamondback moth, using 8-9 gm of powder (it is best used mixed with a carrying agent) per plant. The application should be carried out when the dew is on the plants so that the powder adheres well (117). Trials demonstrated that this treat­ ment killed 80 % of the caterpillars in 4 days.

* A spray made from 4 kg of mammey powder dissolved in 400 lit­ res of water (with added soap as a spreading and adhesive agent) produces in 4 days a 67,9 % control of the caterpillars of the diamondback moth and a 73,6 % control of the larvae of Ascia monuste (117).

* A preparation made by steeping 225 gm of mammey powder in 1,2 litres of kerosene for 24 hours at room temperature and then filtered, is poisonous to cockroaches, flies and ants (117).

93 NEEM - Azadirachta indica Fam. Meliaceae

1. General

Neem is a fast-growing, sclerophyllous tree which is native to the Indian subcontinent, but which is now distributed throughout Southeast-Asia, East and Sub-sahelian Africa, Fiji, Mauritius and parts of Central America.

It grows well in climates from semi-arid to semi-humid and will thrive even in places with less than 500 mm of rain per year. The soil requirements are modest and neem grows equally well on poor, shallow, sandy or stony ground (126). The trees fruit when they are 4-5 years old, on average giving 30-50 kg of fruit per tree. The oil content of the seeds is 35-45 % (2). The effective ingre­ dients are present in all parts of the tree but are most highly concentrated in the seeds (136).

Effective Range

insecticidal, repellent, antifeedant, growth-inhibiting, fungicidal

94 Target Insects

Neem is effective against numerous pests. It has been shown that it can control over 100 species of insects, mites and nematodes (2). Some of them are:

American bollworm Heliothis armigera (82) Aphids general (52) Brown rice plant hopper Nilaparvata lugens (52) Diamondback moth Plutella xylostella (137) Cabbage worm Mamestra brassicae (137) Colorado beetle Leptinotarsa decemlineata (137) Cutworms Agrotis spp. (52) Desert locust Schistocerca gregaria (51) Fall army worm Spodoptera frugiperda (52) Flea beetle Podagrica uniforma (163) Green rice leaf hopper Nephotettix virescens (52) Large cabbage worm Pieris brassicae (137) Leaf miner Liriomyza spp. Mediterranean fruitfly Ceratitis capitata Mexican bean beetle Epilachna varivestis (52) Migratory locust Locusta migratoria (52) Mites general (52) Potato jassid Empoasca fabae Rice stalk borers general (52) Spotted stalk borer Chilo partellus (52) Variegated grasshopper Zonocerus variegatus (118) White-backed rice plant hopper Sogatella furcifera (52) White fly Bemisia tabaci Epilachna chrysomelina (163) Hellula undalis (118) Papilio demodocus (163)

Different views prevail regarding the effectivemess of neem against

Cowpea beetle Callosobruchus maculatus (52) Khapra beetle - Trogoderma granarium (52) Lesser grain borer Rhizopertha dominica (52) Rice weevil Sitophilus oryzae (52)

95 Remarks

* The effective substances of neem loose their potency in sunny conditions being broken down by ultra-violet radiation. It is therefore best to apply neem preparations in the evening (71, 140).

* So far neem preparations seem to have had no, or almost none, negative effects on the Hymenoptera family whose members are useful pollinators and parasites of pest insects and on bees (137).

2. Methods of Use

There are 4 methods of using neem seed:

1. Aqueous extracts 2. Neem oil 3. Neem kernel powder 4. Neem press cake

Basic methods of preparation and some variations are given be­ low.

Aqueous neem seed extract

* Fallen fruits are collected from underneath the trees. The flesh is removed from the seeds and any remaining shreds washed away. The seed is then carefully dried to avoid fungus forming, and stored in airy conditions, e.g. in sacks or baskets.

When required the seeds are shelled, finely grated and steeped overnight in a cloth suspended in a barrel of water at the rate of 25-50 gm/litre. This solution has proved to be very effective against vegetable pests such as cabbage caterpillars, melon beetles and grasshoppers (137).

* KUMAR gives the following method for a water extract of neem: 5 kg of dried pulverised seed are suspended overnight in a cloth in a bucket of water. After about 12 hours the cloth is taken out and squeezed. About 10 gm of soap are separately dissolved in a little water and added to the bucket. The whole is well stirred and made up to 100 litres with water. This pre-

96 paration was used against the Corn earworm (Heliothis armigera) infesting peas, at the rate of 500 litres per hectare. The infe­ station by the caterpillars of H. armigera which had bored into the pods was reduced to 1,1 %. An untreated control sample showed an infestation rate of 7,45 % (82).

* According to experiences in Togo grasshoppers stopped eating immediately after an application of aqueous neem extract. For caterpillars it usually takes 2-3 days to die. However, because the solution becomes less effective with time it is recommended that a second application be given in severe cases.

Experience has also shown that neem extract can be used pre­ ventively. However, this should not be allowed to develop into a regular practice since it may also affect the natural enemies of the pests (118).

* JACOBSON recommends an aqueous extract as repellant with 500 gm neem seed dissolved in 400 litres of water which is sufficient for 0,4 hectares. This application will protect the crop for about 2 weeks if it is not washed away by heavy rain (71).

* 2 kg whole neem fruit and 15 litres of water. The fruit is shredded in an electric mixer with a little water (care should be taken not to overload the mixer). Part of the water is added to the pulp and allowed to stand overnight be­ fore sieving and making up to the full 15 litres. Sprayed weekly this preparation inhibits feeding by the flea beetle (Podagrica uniforma) and inhibits the development of larvae of Epilachna chrysomelina and Papilio demodocus. If it is kept in the dark this neem preparation will remain effective for 3-4 days (163).

Neem oil

See page 152.

Neem kernel powder

See page 152

97 Other methods of use

* According to RADWANSKI (123) neem is effective against nema­ todes. Barley seed can be steeped for 2 hours in a 1 % water solution of ground neem seed. After sowing a 50 % reduction in infestation by nematodes of the genus Pratylenchus was noted.

* Indian farmers in the Pune district plough in 1-2 t/ha of pressed neem cake. This protects eggplants from borers and tomatoes from nematodes and leaf spot disease (166).

* Some farmers spray aqueous solutions of neem press cake onto citrus trees to protect them from leaf miners (166).

Fungicidal effects

In India trials have been carried out with different neem preparations in efforts to control fungi affecting chickpeas, particularly Fusarium oxysporum, Rhizictonia solani, Sclerotium rolfsii and Sclerotinia sclerotiorum.

The following preparations were tested:

Neem oil, fruit pulp, aqueous leaf- and bark extracts.

The seeds of the chickpeas were treated before being sowed in fungi-effected earth.

Neem oil protected the seeds most effectively against fungus attack in the following order: Rhizoctonia solani > Sclerotium rolfsii > Fusarium oxysporum > Sclerotinia sclerotiorum.

The pulp of neem completely prevents the development of resting forms of R. solani. This was a very important discovery since it is these which are responsible for the longevity of the fungus. However, in the case of S. sclerotiorum development of the resting forms was not impaired because they have such strong bodies (143).

Little is known about the effectiveness of neem against fungus diseases. These initial observations constitute the ground for fur­ ther research. Possibly pressed neem cake can be similarly used to control fungus growths in the ground. Other lines of investigation may offer themselves.

98 PERSIAN LILAC - Melia azedarach Fam. Meliaceae

1. General

See page 153

2. Methods of Use

* In trials water extracts of 1:10 and 1:20 caused 100 % deaths of the pupae of the army worm (Spodoptera litura). In the larval stage 1:10 caused 68 % deaths and 1:20 a death rate of 44 %. In these trials water proved to be just as effective a solvent as ethyl alcohol (145).

* A repellant against grasshoppers can be prepared by steeping 150 gm fresh or 50 gm dried leaves in a litre of cold water for 24 hours. Then it is sprayed onto the crops to be protected (28).

PYRETHRUM - Chrysanthemum cinerariaefolium Fam. Compositae

1. General

Pyrethrum is a daisylike perennial plant of the genus Chrysan­ themum belonging to the Compositae family. The white flowerheads possess insecticidal properties.

Pyrethrum originated in the Dalmatian Mountains of Yugoslavia and its cultivation spread throughout the world at the turn of the cen­ tury. The colonial powers introduced it into East Africa and South America and after the First World War Japan became the principal exporter (141).

99 The cultivation of pyrethrum takes place in mountainous regions up to a height of 3000 m, ideally in semi-arid conditions where the winters are cool. Rainfall of 1200 mm with a 2-3 month dry season are best. Pyrethrum can withstand frost down to -12°C, but in situations below about 1600 m the flowers do not set sufficiently. The content of the active substances increases with the height and cooler average temperatures (78).

In places with humus-rich loams and heavier rainfall the plant grows more profusely, but the insecticidal content is less plentiful than when it grows in poorer, drier situations. The flowers are picked on dry, hot days when they are fully open, and left for a short time in small heaps to warm through before being spread to

dry 3-4 cm thick on mats in an airy, shady place. The harvest produces between 200 and 1000 kg per hectare (80). Pyrethrum flowers are best stored air-tight and in darkness.

Effective Range

Pure contact poison insecticidal, repellent, antifeedant (52).

Through its effect as a nerve poison, it produces erratic move­ ment, excitement and finally paralysis (knock-down effect). The insects can, however, recover from the amounts required to produce the knock-down effect within 24 hours. Larger doses are needed to bring about death (141).

Target Insects

Aphids - general (52) Coffee bugs - Lygus spp. (78) Colorado beetle - Leptinotarsa decemlineata (52) Flea beetles - general (78) Grasshoppers - general (78) Imported cabbage worm - Pieris rapae (52) Large cabbage worm - Pieris brassicae (78) Aspodydia spp. (52) Empoasca devastans (52) Leucinodes orbonalis (52) Ophiomyia reticulata (52)

100 Pyrethrum is effective against numerous caterpillars, beetles, aphids, mites, locusts, thrips, moths etc (35).

Remarks

* .The poisonous effects of pyrethrum on warm-blooded mammals are so slight that it is usually regarded as harmless to man. How­ ever, prolonged contact with the skin can produce a rash, and inhaling dust or spray can cause headaches and sickness (116).

* The toxicity of pyrethrum preparations is considerably increased by the addition of small quantities of rotenone (e.g. derris, tephrosia, lonchocarpus) or nicotine (e.g. tobacco, anabasine) (78).

* The effectiveness of pyrethrum is quickly reduced under the in­ fluence of strong sunlight (151). The addition of anti-oxidants, e.g. tannic acid (present in annona bark) slows down this pro­ cess.

* Substances known as synergists such as sesame oil or piperonyl butoxide enhance the utilization of the toxic substances in pyrethrum either by increasing or prolonging their effect. This means that insects do not recover so quickly after the knock­ down effect.

101 2. Methods of Use

Pyrethrum is used in two ways: as a powder or dust, and as a spray. As a dust it can be used either pure or mixed with a carrier such as talc, lime or diatomaceous earth. These also incre­ ase the adhesiveness (78). When it is used as a spray, pyrethrum is usually dissolved in water, soap solution or kerosene. The kerosene spray has the advantage that the decomposition of the active substances is slowed down (141). Soapy sprays have useful effects on the surface action and increase the toxicity of the pyrethrum. The spray should be applied as soon as it is prepared (78).

* Kerosene-extract 500 gm pyrethrum flowers are steeped in 4 litres of kerosene for half a day. After straining through a sieve or cloth the solution is ready for use. It has been shown that kerosene dissolves about 73 % of the Pyrethrin (the active substances) in 48 hours (141).

* 500 gm pyrethrum powder, 3-4 litres of paraffin. The pyrethrum is steeped in paraffin for a day, stirred occasio­ nally and strained before use. This preparation has been used in plantations in Kenya (92).

* 20 gm pyrethrum powder, 10 litres of water. The ingredients are stirred well together and applied immediate­ ly. For the best effect this mixture should be applied in the evening (126).

* Dufour preparation 1-1,5 kg dried pyrethrum, 3 kg liquid soap and 100 litres of water are being extracted like above mentioned. The addition of soap is supposed to increase the effectivity four-fold (12).

102 QUASSIA - Quassia amara, Aeschrion excelsa, Picrasma excelsa Fam. Simarubaceae

1. General

Quassia amara is a small, 4-6 m tall, tropical tree which is distributed in Central America, Brazil and Surinam. A related shrub, Aeschrion excelsa, which grows in the West Indies, also contains insecticidal compounds. In India, farmers use Picrasma excelsa, which is either closely related to or identical with A. excelsa (70). It is above all the wood which contains the insecticidal proper­ ties, but the roots, leaves and bark all contain quassin to a small degree (13).

Effective Range

Contact- and stomach poison insecticidal, larvicidal, nematicidal, Quassia also acts systemically.

103 Target Insects

Aphids general (133) Diamondback moth Plutella xylostella (13) Caterpillars general (155) Colorado beetle Leptinotarsa decemlineata (70) Leaf miners general (35) Melonworm Diaphania hyalinata Mites general (155) Black carpet beetle Attagenus piceus Silkworm Bombyx mori (70) Hoplocampa spp. (70) Phymatocera aterrima

Quassia proved not effective against:

Codling moth Cydia pomonella (70) Mexican bean beetle Epilachna varivestis (70) Peach aphid Myzus persicae (133)

Remarks

* Beneficial insects like ladybirds and honeybees are not killed by quassia spray preparations (161).

* Because the effective substances are water-soluble, quassia sprays are used against sap feeders. When taken up by the roots, quassia works systemically and is transported into the leaves where it acts as stomach poison (133).

2. Methods of Use

Spray preparations should be used immediately after making up. Since the insecticidal contents vary from place to place as well as methods of preparing the solution, it is advisable to experiment locally to discover optimum quantities as well as preparation procedures (70).

* Because quassia works systemically, plants can be kept insect- free by applying a quassia in water solution to the ground. This is taken up by the roots and distributed throughout the plant (133).

104 * Quassia soap solution I

30 gm quassia chips, 1/4 litre water, 30 gm liquid soap. The quassia chips are boiled in the water for 30 minutes, fil­ tered and the liquid soap added to the filtrate. This is diluted with 3 parts of water before use (35).

* Quassia soap solution II

500 gm quassia chips, 500 gm soap, 20 litres water. Simmer all the ingredients together for 2 hours, then filter and add a further 20 litres of water to the filtrate. As a spray this preparation is effective against sap-imbibing insects, particu­ larly aphids and black ants (92).

* Quassia soap solution III

Boil 500 gm quassia chips in 10 litres of water for some time and let it stand for 24 hours, then filter. A separate solution made from 2 kg soap and 5 litres of water is prepared, added to the quassia decoction and made up to 100 litres with water. Then it is ready to spray.

* Quassia-Tobacco solution

Simmer 50 gm quassia chips in a litre of water for an hour, remove from the flame, add half a cigarette (or a number of cigarette butts) and allow to stand for a day. Strain and add 100 gm of soft soap and 5 litres of water. This solution is highly effective against mealy bugs (144).

Quassia sprays should not be used on plants with edible fruit or leaves. The solution is extremely bitter and is stable and long lasting (92).

105 RYANIA - Ryania speciosa Fam. Flacourtiaceae

1. General

The ryanias are found in the northern parts of South America and the Amazon basin. The most important is Ryania speciosa and the useful parts of the plant are principally the roots and stalks.

Effective Range

Contact- and stomac poison.

It acts slowly, but is highly effective, even when the insect does not appear to have been immediately affected. Eating, movement and breeding gradually cease after contact (70).

Target Insects

Black carpet beetle Attagenus piceus (133) Codling moth Cydia pomonella (133) American bollworm Heliothis armigera (70) European corn borer Ostrinia nubilalis (133) Melon worm Diaphania hyalinata (133) Oriental fruit moth Cydia molesta (133) Imported cabbage worm Pieris rapae (133) Squash bug Anasa tristis (133)

Ryania is not effective against:

House flies (133) Onion thrips Thrips tabaci (116) Pea aphid Acyrtosiphon pisum (133) Red mites Tetranychus spp. (116) Squash vine borer Melitta Cucurbitae (70) Tobacco hornworm Manduca sexta (70)

Remarks

* Toxicity for vertebrates is very low (70).

106 * The active substances are more stable than those found in the Pyrethrin and rotenone bearing plants. This quality endows ryania with a longer during effectivity which lasts in the field from 5-9 days (164, 116).

* Ryania works simultaneously against the maize stem borer and corn smut (134).

2. Methods of Use

Ryania can be used as a powder or a spray. The powder is soluble in water, alcohol, chloroform, acetone, etc. After several extractions in a solvent there remains an amorphous, non-volatile, very stable powder which is 700 times more effective than the ori­ ginal plant material (70).

* Ryania powder Dried roots, leaves or stalks are finely pulverised and mixed with an inert dilutant such as talc or clay. A 40 % ryania powder used at the rate of 42 kg per hectare is effective against maize stem borers when dusted on the plants one week after the moths started to emerge (134).

* Sprays 30-40 gm ryania powder dissolved in 7-8 litres of water and filtered is recommended as a spray to combat the codling moth (161). In fruit gardens spraying against caterpillars and beetles every 10-14 days is recommended (35).

SABADILLA - Schoenocaulon officinale Fam. Liliaceae

1. General

Sabadilla is a perennial, 50 cm tall, lily-like plant which originated in Venezuela, Colombia and Mexico (116). The parts with insecticidal properties are mainly the spikes with immature capsule of seeds (4).

107 Effective Range

Contact- and stomach poison (116). insecticidal, repellent, rodenticidal (4, 52). Target insects

Aphids general (4) Army worm Spodoptera abyssina (52) Armyworm Spodoptera eridania (52) Avocado lace bug Ancysta perseae (71) Cabbage looper - Trichoplusia ni (52) Cockroaches general (52) European corn borer Ostrinia nubilalis (52) Flea beetles general (4) Grasshoppers general (4) Green stink bug Acrosternum hilaris (71) Hairy chinch bug Blissus hirtus (46) Leaf bug Leptoglossus australis (4) Leaf eating caterpillars general (4) Melon worm Diaphania hyalinata (52) Potato jassid Empoasca fabae (71) Silkworm Bombyx mori (4) Stinkbug Bagrada spp. (4) Thrips general (71)

Sabadilla has not proved to be effective against:

Dock aphid Aphis rumicus Peach aphid Myzus persicae Spittle bug Philaenus leucophthalmus

Remarks

* In contrast to freshly pulverised sabadilla seeds, seeds which have been pulverised for a longer period have a greater insecti- cidal action. Trials show that the toxicity of a kerosene extract increases with the passage of time, but is must be stored in the dark. There it will remain stable for 1-2 years. Light reduces the effectiveness rapidly (4).

* At room temperature freshly-powdered sabadilla seeds were not effective. By raising temperature of the extractive, however, all inactive samples became potentially toxic. Temperature levels below 75°C caused the initial increase in toxicity, the optimum

109 temperature being 150°C. This temperature appreared most fa­ vourable for making available the toxic constituents of sabadilla in kerosine.

* Sabadilla preparations are extremely toxic to honey bees.

2. Methods of lise

* A highly toxic preparation can be made by heating 500 gm pul­ verised seed in 4 litres of kerosene for 1 hour at a temperature of 150°C. Heating increases the effectivity (133).

* The toxicity of the powdered seeds is also raised when they are heated without the additon of other substances (133).

* The application of heat to the powdered seed and treatment of the powdered seed with soda ash prior to extraction also increa­ sed the toxicity of inactive compounds to a considerable degree. When using the combination of both soda ash treatment and heat treatment a temperature of 60°C is sufficient to produce an effective extract (4). Lime and wood ash could also be tried to alkalize the solution (59).

* Good results were obtained with aqueous extracts of sabadilla pretreated with soda-ash against grasshoppers and other insects. An exact description of quantities and effectiveness against spe­ cific pests was not given (4).

* A 20 % sabadilla powder effectively reduced the population of potato jassids (Empoasca fabae). Thrips were only moderately reduced (71).

* A 10 % sabadilla powder diluted with talc and used at the rate of 120 kg per hectare produced a more than 90 % reduction of hairy chinch bugs (Blissus hirtus) (46).

* Sabadilla powder in combination with derris dust successfully controlled cabbage worms and tent caterpillars and was particu­ larly effective against Tephroclystia absinthieta (4).

110 SWEET FLAG - Acorus calamus Fam. Araceae

1. General

See page 158

2. Methods of Use

Tests with dried rhizomes in powdered form or in water solutions have demonstrated the effectiveness of sweet flag against beetle larvae and aphids. Water solutions benefit from the addition of a little soap which disperses them better over the leaf and makes them more adhesive.

A useful mixture is 30 gm rhizome powder in 4 litres of water which is either allowed to stand cold for a day or boiled for 45 minutes and cooled before spraying (149).

TOBACCO - Nicotiana tabacum, N. rustica, N. glutinosa Fam. Solanaceae

1. General

Tobacco is a native of South America, but today it is grown all over the world, and its cultivation is successful under many ecological conditions. It does not succeed on water-logged soils and on soils with high salt content. It thrives in warm situations and needs sufficient rain during the youth stage (47, 131).

Leaves and stalks are the plant parts used in crop protection. The highest concentration of nicotine is present in the stalks and leaf ribs.

Ill Effective Range

Contact-, stomach- and respiratory poison, insecticidal, repellent, fungicidal, acaricidal.

Remarks

* Nicotine is one of the most toxic organic poisons. The nicotine of half a cigarette is sufficient to kill a fully-grown adult human. Therefore it is crucial to avoid any contact with the spray during the application. After the treatment, food plants are not to be eaten for 3-4 days. This time is required for the nicotine (toxic to warm-blooded mammals) to decompose (35).

* Tobacco sprays are more effective when they are used at tempe­ ratures above 30°C (84).

112 Target Organisms

Aphids general (52) Cabbage worms general (52) Caterpillars general (35) Flea beetles general (52) Grain weevils general Leaf miners general (35) Mites general (52) Stem borers general (52) Thrips general (35) Rust in beans and wheat (6) "Kasahui", fungus disease of potatoes (60) Leaf curl virus (36)

2. Methods of l)se

* A spray can be prepared by soaking 1 kg of bruised tobacco stalks and leaves in 15 litres of water for one day. A small handful of soap flakes is added as adhesive agent. After one day the plant parts are filtered out. The spray is applied immediately with a sprayer, using a very fine nozzle. All uten­ sils should be thoroughly cleansed after use. * 250 g of tobacco, 30 gm liquid soap, 4 litres of water. The mixture is simmered for 30 minutes. Then it is diluted at 1 part tobacco decoction : 4 parts water. The effectiveness is increased when a little slaked lime is added. This solution con­ trols insects like caterpillars, beetles, stem borers, leaf miners, aphids, thrips and creatures which pass some stage of their life cycle in the soil like cutworms. It does not affect ladybirds and their larvae or hoverflies (35).

* In China rice is protected against stem borers by immersing to­ bacco stalks in the roughly 5 cm deep water of the paddy fields. 150-300 kg of stalks are used per hectare. This treatment should be employed after the harvest and lasts for about 2 weeks (55).

113 * The following tobacco solution was used successfully in the La Paz region of Bolivia against aphids and kasahui, a fungus disease of potatoes (60): 4 litres boiling water, 1/2 kg tobacco leaves, 1/2 tablespoon quicklime and 1/2 tablespoon cactus juice (opuntia).

* Beans and wheat which were treated with a spray prepared from tobacco (N. glutinosa) containing 0,01 % active compounds, were almost completely protected against rust disease (6).

* As a preventive measure against the leaf curl virus which is carried to green peppers by thrips, young plants in the seed­ beds were dusted with tobacco powder before being planted out in the field (36).

TURMERIC - Curcuma domestica Fam. Zingiberaceae

1. General

Turmeric is a perennial plant with a short stem and tufted lea­ ves. It originated in India and Southeast-Asia where it grows in dedicious monsoon forest. In the meantime it has reached worldwide distribution. It thrives up to 2000 metres in places with a rainfall of 1000-2000 mm. It grows well on loams and alluvial soils, but does not tolerate water logged soil conditions. It is often grown as a successional crop to rice or sugar cane, but also in mixed cultivation with vegetables. It is an important spice and has con­ siderable commercial importance as one of the principal ingredients of curry. Turmeric responds well to organic manures and yields from 13.000-33.500 kg/ha of rhizomes.

The rhizome is the plant part being used in crop protection.

Effective Range

Insecticidal and repellent (52).

114 Target Insects

Army worms Spodoptera litura (145) Caterpillars general (114) Cowpea beetle Callosobruchus maculatus (120) Grain borer Sitophilus granarius (72) Lesser grain borer Rhizopertha dominica (72) Mites general Rice flour beetle Tribolium spp. (72) Rice weevil Sitophilus oryzae (52)

115 2. Methods of Use

There is relatively little information from practical experience on the use of insecticidal plants and most of it refers to storage protection:

* PERIES in Sri Lanka describes the following method (114): - Turmeric root is shredded and cow urine added. The mixture is diluted with water in proportions between 1 : 2 and 1 : 6 and used against insects and in particular against caterpillars. The exact quantities are not given. - Threads can be dipped in grated turmeric and stretched over the fields which have then a repellent effect.

* In trials a turmeric preparation caused a 90-100 % death rate of the army worm (Spodoptera litura) in 2 days. Dried rhizomes were grated and extracted with acetone and the solution was di­ luted with 5 parts of water (145).

116 117 FURTHER INSECTICIDAL PLANTS OF IMPORTANCE

Plant parts Effective Distribution Name used range

ANDEAN LUPIN Andes Seeds antifeedant Lupinus muta- fungicidal bilis nematicidal

BASIL Worldwide Leaves, insecticidal, Ocimum basilicum ripe seeds, repellent, essential oil growth inhi­ biting, against ticks

COCKROACH PLANT Central America Leaves, Contact- and Haplophyton stems stomac poison cimicidum insecticidal

CROTALARIA Fully ripe seeds insecticidal Crotalaria ochro- repellent, leuca nematicidal

CROTON OIL TREE Southeast Asia Seeds, insecticidal Croton tiglium roots molluscicidal fish poison

DENNETTIA Edible fruit, Contact poi- Dennettia tripe- oil of the fruit son, tala insecticidal

EUCALYPTUS Worldwide Leaves repellent Eucalyptus spp.

118 Target organisms Methods of use

Unspecific insecticide The cooking water of lupines which (42) against soft bodied derives from food preparation is (165) insects and snails. sprayed undiluted onto affected plants.

Aphids, Colorado beetles, A 2 % emulsion is made from the (68) flies, maggots, mosquitos, essential oil and used as a spray, potato tuber moth, spider mites.

Army worms, cabbage Dried powdered leaves or an aque- (70) worms, codling moths, co-ous extract are made with the (133) lorado beetle, european stems. A rate of 3,3 % plant mate- (147) corn borer, grasshoppers, rial was effective against 'flying mexican bean beetle, insects', mexican fruit flies, squash bugs.

Maize weevil, A handful of fully ripe seeds are (49) rice weevil. spread over and between each 5 (50) sacks of beans or maize.

Aphids, army worms, A water extract is made from (7) flies, silkworms, snails. the pulverised seeds and used against aphids. No quantities were given. See also p. 123

Bean bruchids, cock­ For storage protection see p. 164 (69) roaches, maize weevils, The oil is not watersoluble which variegated grasshopper. limits its use in the field. How­ ever its use as an emulsion is possible.

Bean bruchids, To protect beans in store 10-20 (3) potato tuber moth. eucalyptus leaves should be dis- (34) tributed per kg. Potatoes should be stored on a bed of leaves.

119 Name Distribution Plant parts Effective used range

HORSERADISH Worldwide Leaves bactericidal TREE fungicidal Moringa oleifera

MELON TREE Worldwide Leaves fungicidal Carica papaya

THUNDERGOD VINE Rootbark larvicidal, Tripterygium repellent wilfordii

TOMATO Worldwide Leaves repellent, Lycopersicon prevents egg esculentum laying

YAM BEAN South- and Cen- Ripe seeds Contact-and Pachyrrhizus tral America stomach poison erosus insecticidal, antifeedant

120 Target organisms Methods of use

Phytium debangemum, The leaves are worked into the (9) (fungus attacking mainly soil one week before sowing. This (158) seedlings). time is sufficient to release the effective substances into the soil. Principally used to protect seed­ lings in seedbeds.

Coffeerust, 1 kg of finely shredded leaves (130) powdery mildew. is shaken vigorously in 1 litre of water and then squeezed through a cloth. 1 litre of this liquid is diluted with 4 litres of soap solu­ tion (made by dissolving 100 gm soap flakes in 25 litres of water) and then used as a spray.

Aphids, cabbage worms, Powder: 2 kg root powder dissol- (15) codling moths, cockroa­ ved in 400 litres of water killed (70) ches, european corn 81-96 % of the larvae of the euro­ borer. pean corn borer in 48-72 hours.

Cabbage worms, Tomato stems are finely shredded, (81) diamondback moth. covered with the same quantity of (144) hot water and allowed to stand for 5 hours. After sieving this solution is sprayed onto the cabbage plants. It is best used when the butter­ flies of the forementioned pests are beginning to fly. The spray irri­ tates them and prevents them from depositing their eggs.

Aphids, army worms, To make a spray, 2 kg pulverised (13) cabbage worms, diamond- yam beans are stirred into 400 (33) back moth, flea beetles, litres of water. (70) mexican bean beetle, stink bug, caterpillars general.

121 MIXTURES

Effective sprays are often prepared from a mixture of different insecticidal plants. Most of these plants we have already met, but there are some additions of locally used ones.

Chilli - Mixture I

To control aphids a strong mixture of chillipeppers, garlic and onions can be made. The three ingredients are finely grated, stirred well with water and sieved. To increase the adhesive properties of the solution liquid soap should be added (161). The quantities used were not given by the contributor, so experiments should be made with different concentrations on small trial plots.

Chilli - Mixture II

The following chillipepper/garlic mixture has a repellent effect on leaf-eating pests:

A handful of finely shredded chillis and garlic is well stirred in a litre of water, filtered and used as a spray. When no spray is available the liquid can be distributed by means of a bundle of grasses flicked over the plants. A spreader can also be manu­ factured from a tin by perforating it at the base (146).

Chilli - Mixture III

According to a source in the Philippines a mixture of the plant sap of chillipeppers, lemongrass and agdao leaves is very effective against insects. It is said that even the 'worst pests' of rice can be controlled with this preparation.

Each 5-6 tablespoons of the juice mixture from the three plants should be stirred with 4 litres of water and shaken lightly before use. It was stated that 87 % of pests were killed with this prepa­ ration, but does not specify which (9).

122 Chilli - Mixture IV

Rice farmers is Southeast-Asia use the following preparation against stem borers:

Tubli roots (Croton tiglium) Dried tobacco leaves Chillipepper

The tubli roots (no quantities given) chopped small and pounded, are mixed with 8 litres of water and the liquid reduced to half by boiling. 50 gm dried tobacco leaves are also mixed with 8 litres of water and also reduced to half by boiling. 4 tablespoons of grated chillipepper are stirred in 2 glasses of water and again reduced to half by boiling. Finally all three liquids are strained and thoroughly stirred together. For the application 1 glass of this mixture is diluted with 15 litres of water (7).

Derris - Mixture

In the Philippines farmers use the following mixture against the rice pest Leptocorisa acuta:

Derris roots (tobli) Seeds of Jatropha curças (tuba) Seeds of Barringtonia asiatica (botung)

The plant parts are dried and powdered. Hot water is then poured over them and the mixture allowed to stand for 24 hours before filtering and adding soap. No quantities were given (17).

123 ANIMAL SUBSTANCES

COW URINE

Cow urine has been used in Sri Lanka with interesting results:

Target organisms

* Insect pests Cow urine has achieved very good results against mealy bugs and other insects on green beans, melons, cabbages, spinach, tomatoes, okra etc. It has also been used successfully against thrips and mites (113). In Zimbabwe both cow and human urine have achieved good re­ sults against aphids, caterpillars and mites (127).

* Fungi

It was generally announced but not specified against which fungi the urine is effective (115).

* Virus disease

Particularly against leaf curl in chilli peppers and mosaic virus in chillis and tomatoes (66).

Methods of use

When cow urine is used for plant protection, adequate facilities for its collection must be provided. In Sri Lanka the cows were penned overnight on a concrete floor which sloped to a tank. For 3 cows a tank 0,75 m x 1,35 m proved sufficient. The collected urine was allowed to stand for 2 weeks. Being exposed to sunlight during this time is considered beneficial. As a general guideline PERIES dilutes the urine with 6 parts water. But the right proportions are to find out by the farmer. Tender garden vegetables for example, require a less concentrated solution than fully grown citrus trees. Too strong a solution can produce a burning of the leaves (115).

124 In his first trials RANKIN applied sprays at 1 part urine : 2 parts of water. Aphids were killed up to 60 % and the american bollworm (Heliothis armigera) up to 10 %. Undiluted urine killed 95 % of the aphids, 67 % of the caterpillars and 83 % of the mites. RANKIN suggests a mixture of 1 : 1 because undiluted urine causes slight damage to the plants (127).

Various plant ingredients can be added to the urine. PERIES has employed assofoeitida, turmeric, neem and tobacco. Such spray preparations can be used preventively. Thus infestation pressure may be reduced if sprayed in regular intervals. JATRANZA suggests 2-3 sprayings of cow urine at weekly intervals against mosaic virus disease (66).

In the case of uncertainty about the proper concentration, one should try different dilutions at few plants. The right dilution can also be found out by the odour - it should smell mildly.

COW DUNG

Cow dung has likewise proved useful in plant protection. 2-3 dried cowpatches are mixed with 10 litres of water in a bucket and stirred daily for 14 days. Stone or clay dust can be sprinkled into the bucket if the smell becomes unpleasantly strong. These reduce the smell and add useful minerals.

After a 2 weeks fermentation time the mixture is diluted from 3-5 times with water, and can then be used as a spray. It is described as extremely effective and can be applied to all green parts of vegetables and fruit. Although the contributor does not make any specific claims about its results, it seems to be a method worth investigating. Any superfluous liquid can be usefully employed as a fertilizer (144).

TREE PROTECTION

Newly planted saplings are often damaged by wild or farm ani­ mals. These can be protected by using the animals' own dung or urine.

125 * In Ghana fresh dung of the animal to be kept away is mixed with water into a 'soupy' consistancy. This 'soup' is allowed to stand for 3 days and then applied to the saplings (38).

* A farmer on one of the East Indian Ocean islands has protected young trees from goats with a mixture of goat, cow and hen manure, clay dust and diluted urine. With that he painted the woody parts of the sapling at monthly intervals.

126 ASHES

Following several application methods of woodash are presented:

WOOD ASH I

1/2 cup wood ash, 1/2 cup lime, 4 litres of water.

Mix all together, allow to stand for some hours and then strain. This spray is effective against pests of the cucurbits such as maggots and cucumber beetles (9). Quantities used and timing of application were not indicated by the contributor.

WOOD ASH II

Mix 6 teaspoons of kerosene with 1 kg of wood ash. Dust vegeta­ bles early in the morning, twice a week. It is quite effective against sucking type of insects. Note: Avoid coconut shells or husks ashes, which is quite harmful for vegetable leaves. This method is recommended as a preventive measure. It is no longer effective once the plants are heavily infested (128).

WOOD ASH III

Wood ash preparations are also effective against fungus diseases such as mildew (125), oidium and rust (34). RANKIN describes the following preparation which is used in Zimbabwe.

A heaped tablespoon of wood ash is stirred vigorously into a litre of water, left to stand overnight, strained and mixed with a cup of sour milk or buttermilk. Before spraying, this mixture is dilu­ ted 3 times with water, but the strength of the solution should be checked by a trial on a small area of plants to discover the most effective dilution (126).

127 WOODASH IV

Wood ash is used in the highlands of Ecuador and Peru in dust form. The ash usually derives from the cooking fire. It consists of twigs and logs, particularly of the eucalyptus tree. According to the harvest season ash from straw, maize cobs and quinua is also used so that there is no strict composition (65).

Against the leaf miner (Liriomyza huidobrensis) wood ash is em­ ployed successfully. It is applied either as dust or diluted in water (129).

128 BAITS AND TRAPS

CUTWORM BAITS

Two different preparations of cutworm-baits could be identified:

Cutworm-Bait I

Mix together equal parts of hardwood sawdust, bran, a 'good' portion of molasses and enough water to make the mixture sticky. Of this preparation a handful is distributed over the endangered crop at evening twilight. The molasses attracts the cutworms and as they pass through it, it will stick to their bodies and harden towards the morning. Thus they cannot bore their way back into the earth and are rendered vulnerable to birds or they dry out in the sun. This method is of course not 100 % effective, but it does eliminate very considerable numbers of cutworms (161).

Cutworm Bait II

100 g bran, 10 g sugar, 10 cc pyrethrum powder, 200 cc water.

Mix the ingredients thoroughly together and set out in the garden near to endangered plants. Cutworms are attracted by this mix­ ture, eat it readily and die (81).

FRUIT FLY TRAPS

Traps for fruit flies are baited with a mixture of protein and sugar. Fruit flies need protein during their egg laying period. The traps are so constructed that once the flies have entered to take the bait, they can no longer escape (126).

It is best to bait the traps 6-8 weeks before the fruit ripens.

129 Baits

* 1 litre of water 1/2 cup urine 1 1/2 teaspoons vanilla essence 100 gm sugar 10 gm pyrethrum

All the ingredients are well mixed together. Small jars each hol­ ding 50 cc are hung at 3 metre intervals throughout the garden (126).

* The peel of an orange or cucumber or their fruitpulp. 100 ml ammonia or urine 1/2 litre of water

All mixed well together and allowed to stand overnight. The mixture is diluted with 15 litres of water and poured into Type I traps (126).

* 1 teaspoon pyrethrum 1 cup honey 1 teaspoon vanilla essence 1 cup fruit pulp of cucumber etc. 10 litres of water

These ingredients are well mixed and 1/2 cupfuls poured into Type II traps (126).

* 6 cc yeast extract, e.g. Marmite or Vegemite

0,5 gm sodium sulphide (Na2S) 1 litre of water

This bait has been used in Type II traps with success by an Australian farmer (166).

130 Traps

Simple traps can be made from plastic water bottles:

Type I Wire loop for Type II

Source:(35) Source:(35)

Type III

An old plastic bottle is cut around a line below the shoulders (see Fig.l) and separated into sections A and B. The lower section (A) is fittet with a simple wire suspension hook, slipped over the shoulders of the bottle (see Fig.2) and sealed with a white, yellow or red rubber band (C) which should not be more than 2 cm wide (see Fig.3).

The liquid bait is poured in through the neck of B so that when the trap is inverted and suspended it settles round the shoulders as illustrated (Fig.3).

131 Source: (156)

The bait attracts the fruit flies. But in its immediate vicinity the smell is so strong that the flies loose orientation. It is the rubber band that gives orientation to the fruit flies in the last few me­ ters. They will try to crawl under it and happen to enter through the bottle neck from where they cannot escape. If the band is too wide they will tend to settle on it and will not enter the bottle. .

Once they have been tempted up through the neck the flies attempt to escape through the transparent sides of the bottle, which appear to offer an obvious exit. After a time they become confused and fall into the liquid and drown.

Thus the trap is constantly renewed with protein and water hardly evaporates due the the construction. This type of trap has a long effective life and rarely needs to be replaced (156).

132 LIGHT TRAPS

Light traps can provide useful information about the population dynamic and the development of pest populations (monitoring). They also serve to catch night flying insects. The highest catches are obtained by lamps like U.V. or Petromax (24). RANKIN found 200 watt electric lamps to be successful for moths, mosquitoes, chaffer beetles and the american bollworm (126). Other sources use simple kerosene lamps (39).

Light traps are made als follows:

A wooden framework, usually a tripod, is anchored firmly in the ground. A light source, which can be either an oil lamp or an electric bulb, is mounted on the frame and a shallow bowl of water is placed immediately underneath (5 cm away). A couple of spoonfuls of oil can be added to the water so that when the moths fall in after being attracted by the light, the oil sticks to their wings and they cannot fly away again. The whole construction must be very stably built so that it cannot be blown down or knocked over by animals (39, 126).

Examples of light traps:

A simple tripod of wooden poles (e.g. bamboo) with a lantern (kerosene) suspended over a bowl of water. The construction must be securely built and anchored so that it does not collapse, and cannot be blown or knocked down. Fire risk must be born in mind and the lamp must be so hung that the wood does not catch fire (39).

(Source: 39) 133 The lamp can be situated at different heights above the ground. If the light intensity is varied, a greater variety of insects or more insects will be attracted. The lantern can stand directly in the water, but care should be taken to weight it down because when it becomes lighter as the oil burns away, it may float and overturn (39).

(Source: 39)

If electricity is used it must be en­ sured that neither the cable nor the bulb can come into contact with the water. These would constitute a fire risk (39).

134 The following species can be caught with light traps:

American bollworm Heliothis armigera (126) Army worms Spodoptera spp. (67) Brown rice plant hopper Nilaparvata lugens (67) Cutworms Agrotis spp. (67) Green rice leaf hopper Nephotettix nigropictus (67)

Rice black bugs - (67) Rice gall midge Orseolia oryzae (67) Rice stem borers general (67) Tomato hornworm Manduca quinquemaculata (124)

The optimum timing for placing light traps depends on the life cycle of the insect and the development stage of the crop. The best time is of course, soon after the adult moths have emerged, but before they have laid their eggs.

The optimum distance between 200 watt lamps is 100 m according to RANKIN, because each such lamp has an effective working range of 50 m. He places them around a garden or field (126).

ARMY WORM TRAPS

For army worms and other marching caterpillars a trap of the following kind can be constructed. It is mainly suitable for tree nurseries and seed beds.

A trench about 60 cm wide and 45 cm deep is dug along the side of the garden. The army worms can be destroyed by rolling a log backwards and forwards over them, or the trench can be filled with straw or similar materials and set alight (74).

135 LEAF MINER FLY TRAP

The CIP (International Potato Center) in Lima has tested the following traps for catching the leaf miner fly (Liriomyza huido- brensis).

Yellow painted boards, about 30 cm x 30 cm, coated with adhesive, are erected vertically at a height of 60 cm above the ground. In 3 days each board caught between 16.000 and 18.000 flies, which on average mean a significant reduction from 9 to 2 individuals per growing plant (32).

WHITE FLY TRAP

White flies are attracted optically by yellow surfaces. A 20 cm x 35 cm yellow-orange painted board, coated with oil or other ad­ hesive substance, can be very effective when hung in a greenhouse (161).

TRAPS FOR RATS AND MICE

136 Rats and mice in corn fields, house gardens or the vicinity of grain stores can be caught by sinking a 20 litre metal drum in the ground. 3-5 cm should protrude above the surface. 5 litres of water are poured into the drum and a few peanuts added. Round the inside of the drum, at a depth of 3 cm a generous ring of peanut butter is smeared. This is very attractive to rats and mice, but when they attempt to eat it they overbalance and fall into the water. It is impossible for them to jump out and they soon exhaust themselves and drown. It has been observed that such traps can catch over 50 rats and mice in 2 days (125).

137 OTHER METHODS

BAKULO-VIRUS

Some caterpillars are highly susceptible to a particular virus disease. To combate such caterpillars one can promote this lethal disease with a spray prepared from diseased specimen.

The raw material for the spray are virus-infected caterpillars that can be found in the field. They can easily be recognized with a practised eye. Infected caterpillars of cabbage loopers (Tricho- plusia ni) become when first affected white and inactive and tend to move to the upper parts of the plant where they hang from the underside of the leaves. In the last stages they turn black and erupt into liquid.

8-10 of the infected whitish caterpillars are homogenized in a mixer with water and diluted to a volume sufficient to spray over about half a hectare. The quantity of water needed for the avail­ able spraying technique is not decisive but the amount of infected caterpillars. After 3-4 days the infected caterpillars get sick and die. It is crucial to apply this spray as early as possible to avoid the caterpillars causing enormous damage before they die. This requires a thorough observation in endangered regions and immediate action.

Another way of spreading the virus disease among caterpillars is by using the dormant forms of the virus which are very resistant against external influences. These are gained by allowing chopped virus-infected, dead caterpillars (the type that is used above) to ferment for several days in an open pot filled with water at room temperature. The dormant forms sediment as a whitish layer at the ground. The watery fraction above can be poured away. Dormant forms can be kept in a deep freezer for up to 15 years (167, 168).

138 Positive experiences with bakulo-virus are known from:

American bollworm Heliothis armigera Armyworms Spodoptera litura Cabbage looper Trichoplusia ni Corn earworm Heliothis zea Imported cabbage worm Pieris rapae Large cabbage worm Pieris brassicae Lucerne butterfly Colias philodice

FLOUR PREPARATION I

A spray made from 2 cups of fine white flour well stirred into 5-10 litres of water is very effective against mites and aphids. It should be applied in the morning. As the heat of the sun increases the mixture dries out and the insects are left encrusted in flour, shrivel and die. The coating of flour subsequently falls off the leaves so that their ability to photosynthesise is not essentially affected (125).

FLOUR PREPARATION II

Stir together vigorously 1 cup of buttermilk with 8 cups of fine white flour and 50 litres of water. Spray this onto the affected crop taking care to treat the underside of the leaves. This mixture destroys eggs, larvae and adult mites. 4 applications have been shown to kill 95 % of red mite infestations (126).

MILK PREPARATION

Dilute 1 litre of milk with 9 litres of water.

Sprayed every 10 days this preparation helps to prevent mosaic virus in tomatoes, tobacco and sugar cane (155).

139 KEROSENE-SOAP-EMULSION

500 gm soap, 8 litres kerosene, 4 litres water.

Boil the soap in water until all is dissolved. While boiling hot, remove it from the fire, add the kerosene and churn the mixture thoroughly for about 5 minutes. This is best done by the use of a syringe or force pump spraying the liquid back on to itself. The result should be a smooth, creamy emulsion, without any free oil. If properly made it will adhere to the surface of glass without any free oil. When cool, it becomes a thick, jelly-like mass. This is the concentrated stock solution and must be diluted before use.

For trees or plants in foliage dilute 1 part with 10-15 parts of water.

Acts as contact insecticide for piercing and sucking insects (74). Another source mentions it as useful against scale insects, bugs, mites, aphids and leaf miners (155).

SOAP SOLUTION

30 cc liquid soap and 5 litres of water.

Stir together and use as a spray. A small test area should be treated first to ensure that the soap preparation does not damage the crop plant. It is used against aphids and thrips (74).

ARMY WORM REPELLENT

In the Philippines (Cordillera Central) army worms are controlled by using the plant Murraya paniculata. A bunch of cut branches is put in one corner of the rice field in such a way that the smell of the plant spreads over a wide area. This will repell the army worms and suppress their activity (10).

140 STORAGE PROTECTION

PF^ÇIPLE^^MPREVENTIVE STORAGE PROTECTION«

The protection of farm crops in store, as for field crops takes many forms and includes indirect methods aimed at preventing pests. It is very important to be quite clear which measures are fundamental and which are most suited to a particular situation.

In general it can be said that a fanner can influence the occurance of pests in his crops by carefully choosing certain resistant varieties, planting or sowing and harvesting at the optimum seasons, proper treatment of the crop before storing, siting the store at a favourable place and keeping it scrupulously clean.

1. Choice of Variety

When he chooses the seed varieties a farmer is already influencing the susceptibility of his crop for storage pests. Careful observation and lively exchange of information help to establish which varieties are pest resistant. To some extent resistance de­ pends on factors such as the following:

* Hard intact teguments or tightly closed husks act as a physical barrier to larvae which die before they are able to bore their way through to the germ (43, 26).

* Egg laying sites can be reduced by choosing seed with particu­ lar features. Adzuki bean beetles for instance, avoid laying eggs on rough surfaces (26).

141 * Seeds or germs can themselves contain ingredients which prevent or hinder the growth of larvae. Such varieties of cowpeas are known (26). At UTA in Ibadan/Nigeria, resistant varieties of cowpeas have been developed.

* Modern hybrid maize varieties often possess open cob husks which assist infestation by maize beetles. Traditional varieties are naturally better protected because the husks are more closed (56).

2. Choosing Harvest Time

* If planting and sowing is arranged so that harvest falls in the dry season there are no particular problems with drying the crop. Cultivating the new high yielding and early ripening varieties often means that the harvest falls in the wetter part of the year and this creates new problems of storage.

* Adzuki bean beetles infest beans in the field only when the pods are almost dry. Timely harvesting can therefore ensure that the weevils are not carried into the store along with the beans (86).

3. Drying

Drying is an important procedure in storage protection. It pre­ vents the germination of the seed, the growth of bacteria and fungi, and worsens conditions for the development of pests. A moisture content of not more than 12-13 % - depending on air humidity - is essential before seeds can be safely stored.

The method of drying a farmer chooses depends on the local cli­ mate, the season, the volume of the crop and his financial situation.

Maximum use should be made of sun and wind and suitable mea­ sures should be taken to see that crops which are dry do not be­ come wet again through dew or rain.

The following drying methods are possible:

* Maize can be dried by hanging over a kitchen fire (152).

142 * Maize cobs can be spread in the sun on the ground, on the roof or on frames through which the wind can blow. The corn should be covered at night to protect it from dew (56).

* Simple dryers.

Below two simple dryers will be presented:

Bush Dryer

A bush dryer is made from an empty oil drum which is mounted horizontally and fitted with an outlet pipe. A fire of wood or charcoal is lit underneath and the corn to be dried is spread on a grid over the drum to a depth of 20 cm. The heated air, which passes through the oil drum radiates into the grid and dries the grains.

The disadvantage of this system is that it allows no regulation of the heat. As the heat may reduce the germination power it is advisable not to apply this drying method for seed corn (56).

143 Solar Dryer

Solar energy can be used more effectively by means of a half round tube constructed from tin and painted black. The grain is laid in a rack which can be moved into the tube. Ventilation on both ends is so arranged that there is an equal circulation of air within the tube. Cool dry air enters at the bottom and warm moist air is expelled at the top. The temperature can be regulated by means of simple valves or flaps. Tests have shown that in the dry season the moisture content of the corn can be reduced from 25 % to 15 % in 6 days. In the rainy season 21 days are required. When the corn is simply dried on the ground, it still takes only 6 days in the dry season, but in the rainy season 45 days are required. If the corn is dried in a maize silo the corresponding times are 10 days and 80 days (56).

144 4. Storage Hygiene

"...the most important piece of equipment for storage hygiene is the broom" (56).

The first step towards good storage hygiene is the choice of a suitable site for the store. It should be airy, shady, cool and dry. Temperature variations should be as small as possible be­ cause these encourage condensation water, which in turn gives rise to fungus development.

Crops in store should be protected against dampness rising from the ground, and the site should be safe from flooding in the rainy season. The roof, of course, should be leak proof.

Before newly-harvested crops are introduced, the store should be carefully prepared. Old stored products should be removed and the room thoroughly cleansed. The walls and roof should be watertight and rat proof, and small holes and cracks, which are potential breeding places (especially for khapra beetles) sealed. The whole building should be well aired and opened to the sun, and if possible fumigated (p. 146)

These measures should prevent the recolonisation of new crops by carried-over insects. The surroundings should also be cleared to discourage easy re-infestation by insects and rodents.

145 INSECTICIDAL PLANTS

Many insecticidal plants are useful for field crops as well as for stored products. According to their main use the general des­ cription is found either in the chapter field crops or storage con­ trol.

CHILLI PEPPER - Capsicum frutescens Fam. Solanaceae

1. General

See page 84

2. Methods of Use

* In Benin beans are mixed with dry finely milled earth and chillis before storage. The farmers do not claim 100 % success for this method, but the beans can be kept for several months without suffering greatly from pests. Quantities are not given (56).

* Fumigation

Fires in which pulverised chilli peppers are burnt should be lit monthly underneath the store. The source does not mention the quantities of chillipepper necessary to protect a given volume of stored goods.

Farmers in the Philippines also use this method and vouch for its effectiveness. One disadvantage is that the smoke is very sharp and uncomfortable for eyes and respiratory system (10).

146 HYPTIS SPICIGERA, CASSIA NIGRICANS

In Burkina Faso farmers use the leaves of Hyptis spicigera and Cassia nigricans to control the bean weevil (Acanthoscelides ob- tectus). The leaves of these two plants are laid whole between the beans which are stored in their pods. No details are given regar­ ding quantities.

Trials have been conducted with dried leaves and ether extracts to see if these plants show effects on egg laying and the hatching of larvae. It was shown the ether extracts of both plants reduced egg deposits. Hyptis was more effective at higher concentrations (3 ml/kg), whereas Cassia seems to be more effective at lower con­ centrations. Dried Hyptis leaf powder alone, however, affected the hatching of larvae in proportion to the quantity used, and at 3 gm per kg of beans hatching was reduced by 78 %. Hyptis leaves from Sierra Leone appeared to be less effective.

Powder made from dried Cassia leaves reduced hatching by 91,8 % at 3 gm per kg.

For practical purposes this means that:

* Both H. spicigera and C. nigricans are useful in protecting beans from the bean weevil A. obtectus.

* Beans treated at the rate of 3 gm per kg with dried leaf powder are much less prone to damage from newly hatched larvae.

* There are some differences in the insecticidal properties of the two plants. These might be due to differences in growing sites, harvest time etc. More informations on the factors influencing the content of insecticidal compounds can make their use more predictable.

* Under laboratory conditions extracts with ether demonstrated a reduction in egg deposits, but such methods are hardly transfer­ able to the field. Since, however, both plants undoubtedly have good insecticidal properties it would be worth conducting farm trials using easily available solvents such as kerosene, petrol, local alcohols etc. (85).

* Millet in store is protected against termites by scattering dried Hyptis leaf powder throughout it (68).

147 MUNA - Minthostachys glabrescens, M. mollis Fam. Labiatae

1. General

Muna is a perennial, shrublike plant and includes the genera Minthostachys and Satureja. Of the Minthostachys twelve species are known from Venezuela to Argentina. These are found at heights of 2000 to 3800 m all over the Andes (108).

Muna is harvested mainly in May and June since at this season the plant contains its highest concentration of the essential oils (60).

Effective Range

Repellent, larvicidal, reducing the depositing of eggs, inhibiting germination in store.

Target Insects

Aphids general (32) Potato tuber moth Phthorimaea operculella (32) Bothynus maimon (60) Capitarsia curbata (60) Ludius spp. (60) Premnotrypes solani (60) Scrobipalpula spp. (60)

Remarks

Trials were conducted to investigate traditional methods of pro­ tecting potatoes against the potato tuber moth. The following re­ sults were obtained:

148 Germination losses (%) Rotten tubers (%) rea men Storage time (days) after 120 days 60 120

Lantana spp. 11 24 11 Minthostachys spp. 14 36 14 Cymbopogan citratus 32 46 14 Rice straw 32 45 20 Wood ash 33 54 19 Lime 34 60 11 Control 54 74 32

2. Methods of Use

Farmers of the high Andes near Cuzco and on the Altiplano near Puno use muna to protect potatoes in store (108):

* Storage indoor

In a corner an area of a suitable size is boxed in with planks. Immediately before the potatoes are poured in the floor and sides of the box are lined with muna twigs. When the box is full the potatoes are completely covered with muna twigs. There are variations of this basic method according to local uses, size etc.

149 * Storage outside the house

1. The potatoes are heaped on a bed of muna twigs and chillihua and covered over with twigs. The operation is somewhat easier if the potatoes are heaped against a wall.

2. Some farmers construct a simple silo of earth which includes a small door at one side through which the potatoes can be taken out. The interior is lined with muna and chillihua and the silo is then filled through the still open top and covered with muna twigs and a good layer of straw. Finally a layer of clay about 3 cm thick is smoothed over the surface to keep out the rain.

Straw- Muna- Potatoe;

Muna Chillihua-

* Potato pit

A pit of the requisite size is dug and lined first with straw and chillihua and then with muna twigs, care be taken to build up the sides properly. The pit is then filled and coverd with muna, then straw and finally a 3 cm thick layer of clay.

150 * Storage in a cylinder

A cylinder is constructed out of straw mats with the help of rope or wire and stood on a layer of muna twigs. The cylinder can be used as a container for potatoes, maize or oca. When it is full it is covered with a layer of muna twigs (108).

In trials to examine the infestation by aphids of stored potatoes a repellent consisting of lantana leaves and ashes of Ochroma la- gopus distributed amongst the tubers, was found to be effective (32).

NEEM - Azadirachta indica Fam. Meliaceae

1. General

See page 94

2. Methods of Use

There are two methods to apply neem in storage protection:

1. Powder 2. Oil

151 Powder

* The Indian Research Institute (IARI) in New Delhi has tested the effectiveness of neem seed powder in storage protection against rice weevils, lesser grain borers and khapra beetles. Neem seed powder was mixed with wheat at the rate of 0.5 %, 1.0 % and 2.0 % by volume. The results showed that the 1.0 % and 2.0 % admixture protected the seed against rice weevils, lesser grain borers and khapra beetles for 269, 321 and 379 days re­ spectively. This method should be of interest to village farmers storing grain in smaller quantities (76).

Seeds from legumes were similarly treated and were shown to suffer no deterioration in germination properties (71).

* In another test the IARI examined the effect of neem powder against the khapra beetle and the lesser grain borer when mixed with wheat at the rate of 0.5 %, 1.0 %, 2.0 % and 4.0 %. This showed that the khapra beetles were more vulnerable to neem. After 240 days 24 % of the wheat was found to have suffered khapra damage when treated with 0.5 % neem, but only 8 7o in the case of the 4.0 % admixture. On the other hand, neem powder had no effect on the lesser grain borers, for even with the 4.0 % treatment, 92 % of the wheat suffered insect da­ mage. This result contradicts the foregoing one obtained by the same research institute (23).

Neem Oil

* To produce neem oil by hand, use the dried kernels. These firstly have to be decorticated. In a mortar they are lightly cracked so that the outer husks are freed from the inner seed. The husks are then removed by winnowing. The decorticated seeds are returned to the mortar where they are pounded until they form a brown, slightly sticky mass. A little water is added so as to form a workable paste which forms an almost solid ball. This ball is kneaded for several minutes over a bowl until oil collects on the surface; then press it firmly. Oil will come out in drops. Alternate kneading and squeezing will separate the oil. With this method 100-150 ml of oil can be extracted from one kg of neem kernels. This is about half the oil content (119).

152 If machines are available these can also be used for oil extrac­ tion. Heating of oil is said to not affect the insecticidal proper­ ties.

* To protect beans in store from infestation by bruchids, each kg of beans should be mixed with 2-3 ml of neem oil. Thus a 50 kg sack of beans needs 150 ml of oil at the most. It is important to ensure that the oil is well mixed so that each bean is com­ pletely coated. This treatment protects the beans for six months.

* To remove the bitter taste of oil from the beans before eating they should be covered with hot water for a few minutes and drained after (119).

PERSIAN LILAC - Melia azedarach Fam. Meliaceae

1. General

This tree is closely related to neem. It is a native of the Indian Himalayas, but today is widely distributed throughout the tropics and subtropics. As an ornamental tree it is often used for shade in gardens and for avenues (64).

The dried leaves and twigs have been used for centuries to pro­ tect cloth, books and leather (13). The seeds possess insecticidal properties as well.

Effective Range

Contact- and stomac poison. Insecticidal, repellent, antifeedant, growth inhibiting, effective against ticks (52, 145).

153 Target Insects

Army worms - Spodoptera spp. (52) Asian corn borer - Ostrinia furnacalis (52) Brown rice plant hopper - Nilaparvata lugens (52) Cabbage aphid - Brevicoryne brassicae (52) Citrus red mite - Panonychus citri (139) Corn ear worm - Heliothis zea (52) Grain weevils - general (52) Green rice leaf hopper - Nephotettix virescens (52) Imported cabbage worm - Pieris rapae (52) Large cabbage worm - Pieris brassicae (52) Migratory grasshopper - Locusta migratoria (52) Peach aphid - Myzus persicae (52) Rice gall midge - Orseolia oryzae (139)

The persian lilac proved not effective against

154 Remarks

* There are few reports about the use of persian lilac under farm conditions, but some scientific results are given here in the hope that they can be adopted to field conditions. Because this tree is widely distributed it could make a worthwhile contribu­ tion to natural crop protection methods both in field and store.

* Most of the information about persian lilac is related to storage protection, whereas it can also be usefully employed against pests in the field.

* The germination power of stored wheat which has been treated with persian lilac has not been affected (150).

* The insecticidal and repellent substances present in persian lilac are easily soluble in alcohol, but hardly at all in water (13).

2. Methods of Use

In a trial, ripe seeds were shade dried and finely pulverised in a mortar, then passed through a fine meshed sieve. The resul­ tant powder was thoroughly mixed with undamaged wheat at the rate of 0.5 %, 1.0 % and 2.0 % by weight. In the same way a powder was made from dried leaves and also mixed with unda­ maged wheat, but at the rates of 1.0 %, 4.0 % and 8.0 %. To 100 gm of each of the treated samples 20 grain weevils were introduced.

The effect of persian lilac preparation on wheat in store was examined with regard to:

1. Undamaged seed (Table 1). 2. Population development of the weevils (Table 2).

155 Table 1: Average damage of wheat by the grain weevil Sitotroga cerealella when treated with seed and leaf powder of Persian lilac.

Average damage after (days) Treatment 45 90 135

Seed powder 0.0 8.99 49.99 99.59 per 100 parts 0.5 0.22 8.45 57.75 wheat 1.0 0.09 0.31 0.44 2.0 0.00 0.04 0.13 leaf powder 0.0 9.40 57.65 98.19 per 100 parts 0.5 0.48 11.49 83.31 wheat 4.0 0.08 0.22 0.45 8.0 0.00 0.00 0.04

Thus treatment with 1-2 % seed powder or 4-8 % leaf powder good protection for 135 days.

Table 2: Average numbers of grain weevils (Sitotroga cerealella) developing from the original 20 in wheat treated with seed and leaf powder of persian lilac.

Average weevil population after Treatment (days) 45 90 135

Seed powder 0.0 66.0 100.00 223.75 per 100 parts 0.5 0.0 22.00 45.50 wheat 1.0 0.0 0.25 2.00 2.0 0.0 0.00 0.25 Leaf powder 0.0 80.75 111.25 296.50 per 100 parts 1.0 2.25 30.25 43.50 4.0 0.00 2.00 3.75 8.0 0.00 0.00 0.00

Thus treatment with 1-2 % seed powder and 4-8 % leaf powder showed the lowest grain weevil population after 135 days. This agrees with the results of table 1, which indicates the lowest corn damage for the same treatments.

156 SPEARMINT - Mentha spicata Fam. Labiatae

1. General

Spearmint is a well-known aromatic plant of the temperate zones and the subtropics. It is widely cultivated, particularly in the USA, in Northern India and in Southern Africa.

In storage protection it is the leaves to be used.

Target Insects

Adzuki bean beetle Callosobruchus chinensis (101) Rice flour beelte Tribolium castaneum (79) Rice weevil Sitophilus oryzae (79)

2. Methods of Use

There are two principal ways in which spearmint can be used to protect crops in store:

1. powder, made from dried leaves 2. essential oil

157 Powder

* In trials, shade-dried spearmint leaves were powdered in a pestle and mortar and thoroughly mixed with chick peas in pro­ portions by weight of 0.25 %, 0.5 % and 1.0 %. Adult adzuki bean beetles were introduced and within 48 hours the death rate was 88.8 %, 88.8 % and 96,3 % respectively (101).

* In another trial with rice weevils, spearmint powder at the rate of 0.5 %, 1.0 % and 2.0 % by weight was thoroughly mixed with wheat. In all three cases all the introduced weevils were dead in 15 days. The first weevil died after one day, and in the case of the 1.0 7o and 2.0 % admixtures, all the weevils were dead in 96 hours (79).

Essential Oil

* The effect of essential oils of spearmint on the adzuki bean beetle was tested by emulsifying 0.25 %, 0.5 % and 1.0 % by volume with water. A specific number of egg-infested seeds were dipped into these emulsions and dried in the shade.

The 1.0 % emulsion completely suppressed the hatching of the eggs, but in the case of the 0.5 % emulsion, 29.3 % of the seeds still • hatched the eggs they contained (101).

SWEET FLAG - Acorus calamus Fam. Araceae

1. General

Sweet flag is a perennial plant native to India which has achie­ ved worldwide distribution because of its high medical value. Swamps and still waters are its typical habitats where it can de­ velop considerable stands. It will grow in situations up to 2000 metres. At these elevations it develops its greatest essential oil content (71).

158 Sweet flag is easy to cultivate. Due to its site requirements it does not compete with other crops. In India crver 4000 kg of dried rhizomes per hectare can be harvested annually (149). Even though its cultivation is easy and the possibilities as insecticidal plant in field and store are promising its practical importance is still minimal. Scientific investigation started about 1939.

Effective Range

Insecticidal, repellent, antifeedant, antifertile (94).

159 Target Insects

Adzuki bean beetle Callosobruchus chinensis (52) Army worms Spodoptera litura (52) Fleas general (52) Khapra beetle Trogoderma granarium (52) Large cabbage worm Pieris brassicae (13) Lesser grain borer Rhizopertha dominica (52) Mediterannean fruitfly Ceratitis capitata (52) Melonfly Dacus Cucurbitae (52) Oriental fruitfly Dacus dorsalis (52) Rice weevil Sitophilus oryzae (52)

Remarks * It has been established that sweet flag is not poisonous to hu-mans and warm blooded animals (100). No harmful results have been experienced while handling the essential oil except for a slight uneasiness and itching of the eyes when the treated seeds were looked at constantly for a considerable length of time. (160). * When used against pests in the field, the crop itself suffers no damage (149).

* When used on crops in store, the germination power is not har­ med and the food quality does not suffer (160).

2. Methods of Use

Sweet flag as an insecticide can be used both in field and store. Most of the available information concerns the latter. Practitioners interested in experimenting could contribute a great deal to enhance its practical use.

Published results about the use of sweet flag to protect crops in store are mostly based on scientific work. When transferring scien­ tific results to practical work, data on quantities used are to be considered as a guideline. They have to be adapted to local re­ quirements, as the influences in field conditions are more complex than under laboratory conditions.

160 Rhizomes of sweet flag are used in two ways:

1. Powder 2. Essential oil

* Before grain is stored it should be well mixed with dried, pow­ dered sweet flag rhizome at the rate of 50 kg grain : 1 kg sweet flag (149).

Another source recommends a rate of 100 kg rice : 1 kg sweet flag rhizome (71).

* The effect of the essential oils of sweet flag rhizome on the Adzuki bean beetle (Callosobruchus chinensis) has been investi­ gated by YADAVA (160) with the following results:

5 different formulations were tested with reference to knock-down effect (50 % and 100 %) and mortality (50 % and 100 %). The essential oils were obtained from the rhizomes by steam destil- lation.

No. *"ss° Kerosene (ml) Water (ml) Alcohol (ml) Oil (ml)

1 2 2 100

2 2 - 100 3 4 2 100

4 4 - 100

5 4 - 100

Chickpeas were thoroughly coated with each of the above formu­ lations. About 250 gm of so treated seeds were then put into jars. Into each were then introduced 50 adult weevils.

All formulations were found to be effective. None of the weevils survived and the seed was not affected. Increased concentrations brought about an earlier onset of the knock-down effect and a quicker death, particularly in the case of kerosene prepara­ tions. The protection appears to last longer when the treated seed is not exposed to sunlight.

161 Conclusion:

The dried seeds should be dressed with 2 % or 4 % its solution in alcohol or 2 % or 4 % emulsion in water before taking them to godown. This treatment will keep the storage free of pest for at least 4 months. After that, if necessary, seeds may be re­ dressed or a light spray with its alcoholic formulation on the heap will suffice to ensure the store to be free of beetles for at least another 6 months.

As its 2 % solution or emulsion may become weak within a short time, the 4 % may preferably be used for a long term storage. The seeds dressed with its water-emulsion should by all means be dried before taking them to store. The mixture of essential oil and water should be vigorously shaken before use (160).

TURMERIC - Curcuma domestica Fam. Zingiberaceae

1. General

See page 114

2. Method of Use

* Dried pulverised rhizome is added at 2 % to the stored produce.

This treatment was found to be highly repellent against grain weevils (Sitophilus granarius) and the lesser grain borer (Rhizo- pertha dominica) (75).

162 VEGETABLE OILS

The protection of stored produce such as rice, wheat, maize or beans with vegetable oils is a cheap and simple method. Numerous oils are suitable and their application poses no problems. Tested and successfully used in practice are the oils of peanut, coconut, safflower, mustard, castor bean, cottonseed, soyabean and maize. Sunflower seed oil proves not to be very effective (104, 110).

How do vegetable oils work? The mechanism is not completely clear, but it appears that they affect egg laying, embryo and larva development on the surface of the seed. Vegetable oils cause the eggs and larvae to die before they can bore into the seed. If, however, the larvae do manage to penetrate into the seed, be­ cause, for instance, it has not been sufficiently coated with oil, then the treatment produces no further effect and the larvae will develop normally (97).

As time passes after a treatment, two factors change:

1. Adult females tend to avoid stronger laying eggs on seed which has been treated with oil at least 7 days previously. Very few eggs indeed are laid on seed which was treated 60 days before being newly infested with beetles.

2. The toxic effect on eggs and young larvae decreases with time. In practice this means that the protective coating of oil must be renewed periodically (97). However, it may be that the microclimate of the storehouse may influence also the duration of the protective properties of the oil.

The germination power of oil-treated seeds is judged differently. PANDEY et al. state that Mung beans suffer no damage in germi­ nation (110). On the other hand YUN-TAI-QI notes a diminishing germination capability in wheat as the percentage of oil used in the treatment increases. Thus at 1 ml oil per kg of wheat, 82-90 % of the wheat remains capable of germination, but this drops to between 32.5 and 42.4 % at 5 ml per kg and to between 27.5 and 52.5 % at 10 ml per kg. Therefore he recommends that wheat which

163 is intended for seed should be treated in some other way and that vegetable oils should only be used to protect cereals which are intended for food. Germination appears to be most inhibited by cottonseed and soya bean oil (162).

* Peanut oil mixed at the rate of 5 ml per kg with cowpeas pro­ tects it for about 180 days from the cowpea beetle (Callosobru- chus maculatus). It does not prevent the females from laying their eggs, but prevents the hatching of the larvae. Oil' enter- ring the eggs causes the death of the embryos by suffocation (72).

* In tests conducted on mung beans with cottonseed oil and rice husk oil, concentrations of 0.3 and 0.5 % were used. With 0.6 % cottonseed oil only minimal infestation had occurred after 3 months, and after 6 months only 3,57 % of the seeds were dama­ ged. Rice husk oil at 0.5. % prevented infestation for 4 months and after 6 months only 5,78 % of the seeds had been damaged (110).

* Dennettia oil (Dennettia tripelata - Annonaceae) used at the rate of 1 ml per kg protected cowpeas against the cowpea beetle for more than 14 weeks. It protected maize for the same period when used at the rate of 1 ml per 1.5 kg (69).

* To protect beans in store from the cowpea beetle, neem oil at the rate of 2-3 ml per kg was used. When well mixed this amount should be sufficient to coat the entire surface of the beans with oil. A 50 kg sack requires 150 ml of oil and the protection lasts for about 6 months (119).

164 MINERAL SUBSTANCES AND ASHES

Ash, sand and similar fine substances easily fill the spaces bet­ ween grains and beans. This means that newly hatched weevils are hindered in their activities. They experience more difficulty in finding partners and they are also forced to deposit their entire stock of eggs on relatively few beans. By these means an explosive population built-up is prevented and storehouse losses limited. Such factors as crystal size and shape seem to have an influence on egg laying and development because the activities of adult beetles seem to be little influenced by substances such as ash (159).

Mineral substances work in various ways on the different weevils and require specialised knowledge and careful observation. Locally available mineral dusts should be tested for their suitability.

* Grain weevils (Sitophilus granarius) are extremely sensitive to hard, abrasive mineral dusts like quartz.

*. Rice weevils (Sitophilus oryzae) are likewise extremely sensitive to activated coal, heat-activated clay dust and the ashes of rice husks (56).

Wood Ash

Wood ash is a very suitable material for use by small farmers. It is just as effective as chemical pesticides, but has the great advantage that it is harmless to health and cheap. Farmers need only to make the necessary provisions to collect the ash from their cooking fires.

* Wood ash mixed with an equal quantity of beans offers good protection against the cowpea beetle (Callosobruchus maculatus). Trials in Togo demonstrated that ashes from the wood of Afzelia africana, Ceiba pentranda and Parkia africana are very effec­ tive, cheap and hygienic for protecting cowpeas in store.

165 * In Jamaica the effect of dusts on the adzuki bean beetle (Callo- sobruchus chinensis) in cowpeas was tested. Red loam, wood ash

clay and slaked lime (Ca(OH)2) were thoroughly and evenly mixed into the peas at rates of 0.1 %, 0.2 % and 0.3 %. Wood ash and slaked lime at 0.3 % (3 parts per 1000) showed the best results (73).

* A 10 litre bucket of fine sand mixed with each 100 kg of stored grain or peas gives some protection (40).

* Ashes from the leaves of lantana and Ochroma logopur were very effective against aphids attacking the sprouts of stored potato (32).

Sand

In districts where it is easily obtainable sand can be employed as a means of store protection. It is best used with seeds which are bigger than the sand particles. The intension is that the spa­ ces between the seeds are completely filled and that it can easily be removed again by sieving. Seed and sand should be thoroughly mixed in at least equal proportions, but the more sand which can be used, the better. The top is covered by a layer of sand (166).

166 OTHER METHODS

Goats' Dung Spray

In southern Togo, traditional maize silos, in which the outer walls are made of maize cobs, are sprayed with goats' dung solu­ tion. Probably the strong smell deters insect pests as well as the goats themselves from attempting to eat the stored grain (56).

Heat Treatment

The lesser grain borer (Rhizopertha dominica) can be killed if the grain which it is infesting is heated to 65°C for 5 minutes (56). This process can also be tried in a solar dryer.

167 REFERENCES

1 AHMED, S. (1985), Natural Pesticides hold Promise for Developing Country Farmers. - Ambio, 14 (1): 2 p. 2 AHMED, S. and GRAIGNE, M. (1985) The use of indigenous plant resources in rural development: Potential of the Neem Tree.- Int. J. Development Technology, 3: 123-130 3 ALGEMEEN DIAKONAAL BUREAU (1985) Leusden (NL), ex lit. 4 ALLEN, T.G., R.J. DICKE und H.H. HARRIS (1944) Sabadilla, Schoenocaulon spp. with reference to its toxicity to houseflies. - J. Econ. Entomol. 37 (3): 400-407 5 ANONYMOUS (1928) Derris als Insektizid. - Tropenpflanzer : 280-281 6 ANONYMOUS (1975) Natural fungicides from tobacco suggests new approach for plant disease control. - World Crops, Sept./Oct.: 237 7 ANONYMOUS (1977) Peasants against 'modern' technology. - Asian Action 11: 4 (Thai­ land) 8 ANONYMOUS (1984) Ideas that work: Organic Pesticides. - Gambian Field Worker's Magazine 34: 11 9 ANONYMOUS (no year) Bio-Sprays. - Unpublished manuscript, Philippines

10 ANONYMOUS (no year) Internal document on local crop protection practices. - Unpub­ lished manuscript, Philippines. 11 ANONYMOUS (no year) Pyrethrum Bureau of Kenya. - Pyrethrum Post 15 (4) 12 APPEL, O. (1939) Handbuch der Pflanzenkrankheiten. 6. Bd., 1. Halbband, Paul Parey, Berlin 13 ATWAL, A.S. und H.R. PAJNI (1964) Preliminary studies on the insecticidal properties of drupes of Melia azedarach against caterpillars of Pieris brassicae. - Indian J. Entomol. 26: 221-227

14 BARNER, J. (1943) Die Nutzhölzer der Welt, 3. Band, Verlag J. Neumann, Neudorf

15 BEROZA, M. und BOTTGER, G.T. (1954) The insecticidal value of Tripterygium wilfordii. - J. Econ. En­ tomol. 47 (1): 188-189

168 16 BHATNAGAR-THOMAS, P.L. und PAL A.K. (1974) Studies on the insecticidal activity of garlic oil. 1. Differential toxicity of the oil to Musea domestica nebulo Fabr. and Trogoder- ma granarium Everts. - J. Food Science and Technology 11 (3): 110-113 17 BLAUW, W. (1986) ex lit. 18 BLUNCK, H. (1953) Handbuch der Pflanzenkrankheiten, Bd. 5, 2. Teil, Paul Parey, Berlin 19 BLUNCK, H. (1956) Handbuch der Pflanzenkrankheiten, Bd. 5, 5. Aufl., Paul Parey 20 BOHLEN, E. (1978) Crop Pests in Tanzania and their Control. - Verlag Paul Parey 21 BROWN, E.S. (1970) Control of the African Armyworm, Spodoptera exempta (Walk.) - an appreciation of the problem. - East Afr. Agric. For. Journ. January: 237-245 22 BURKILL, H.M. (1985) The Useful Plants of West Tropical Africa. - Vol. 1, Families A-D Ed. 2, Royal Botanic Gardens, Kew 23 BUTHAN, D.K. (1971) Studies on the efficacy of neem seed kernel powder against stored grain pests. - Indian Agric. Res. Inst., Division of Entomology, New Delhi 24 CARL, K. (1986) ex lit. 25 CEMAT (1985) Plantas con propiedades pesticidas utilizadas en la proteccion vegetal. - Guatemala 26 CENTRE OF OVERSEAS PEST RESEARCH (Ed.) (1981) Tropical Grain Legumes 27 CHATTORAJ, A.N. und TIWARI, S.C. (1965) A note on the insecticidal property of Annona squamosa. - Proc. Nat. Acad. Science (India) 35, Sect. B, Part IV: 351-353 28 CHEVALIER, A. (1947) Les Plantes a Rotenone. - Rev. Intern. Bot. Appl. Agr. Trop. 27 (297-298): 295 29 CHEVALIER, A. (1947) - Produits insecticides tirés de deux plantes tropicales, Mammea et Melia azedarach. Rev. Intern. Bot. Appl. Agr. Trop. 27 (295-296): 1314

30 CIAT (1978) Field Problems of Beans in Latin America. - Series GE-19, Cali/ Kolumbien 31 CENTRO INTERNACIONAL DE PAPAS (1978) Annual Report, Lima/Peru 32 CENTRO INTERNACIONAL DE PAPAS (1982) Annual Report, Lima/Peru

169 33 COBLEY, L.S. (1976) An Introduction to the Botany of Tropical Crops. - Longman, London 34 COMISION DE PROTECCION INTEGRADA DE CULTIVOS (Ed.) (1985) Memorias del seminario sobre nuevas regulaciônes para el uso y manejo de plaguicidas. - Unveröffentlichtes Manuskript, 7 p. Quito/Ecuador 35 CONACHER, J. (1980) Pests, Predators and Pesticides. - Organic Growers Association, W. A./Australien 36 COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH (Ed.) (1959) The Wealth of India. A dictionary of indian raw materials and industrial products 37 CROOKER, P. (1979) A home produced insecticide: Derris malaccensis. - Alufua Agric. Bull. (W.Samoa) 4 (3): 8-10 38 DCFRN ( no year ) Planting Trees. Part 5 - Care of trees after transplanting, Package 10-6, The Developing Countries Farm Radio Network, Toronto/Kanada 39 DCFRN ( no year ) A light trap for insect pests. - DCI/E 11, 6 p., The Developing Countries Farm Radio Network, Toronto/Kanada 40 DCFRN (1984) ex lit. - The Developing Countries Farm Radio Network, Toronto/ Kanada 41 DEB-KIRTANIYA, S. et al. (1980) Note on insecticidal properties of the fruits of chilli. - Indian J. agric. Sei. 50 (6): 510-512 42 DICHT, M. (1985) Neues über biologische Pflanzenschutzmittel. - Biolog. Land- und Gartenbau 3/4: 6-10 43 DOBIE, P. (1984) Biological methods for integrated control of insects and mites in tropical stored products. - Trop. Stored Prod. Inf. 48: 4-8 44 EDA ( no year ) People's Workbook. - Johannesburg/RSA ,

45 FACULTY OF AGRICULTURE, FORESTRY AND VETERINARY SCIENCE (Ed.) (1983) Proceedings of workshop on resource-efficient farming methods for Tanzania, May 16-20, 1983, Rodale Press 46 FILMER, R.S. and SMITH, Ch.L. (1946) Sabadilla and DDT to control the Hairy Chinch Bug. - J. Econ. Entomol. 39 (3): 309-313 47 FRANKE, W. (1985) Nutzpflanzenkunde. - Thieme Verlag, Stuttgart 48 FRÖHLICH, G. (1974) Pflanzenschutz in den Tropen. - Verlag Harri Deutsch 49 GEROLD, P. OSB ( no year ) Sunnhemp - Crotalaria ochroleuca. - Peramiho/Tanzania

170 50 GEROLD, P. OSB (1985) Radiointerview über Crotalaria ochroleuca. - Missionsblätter der Benediktiner-Missionare in Uznach: 82-93, Uznach/Schweiz

51 GILL, J.S. und C.T. LEWIS (1971) Systemic action of an insect feeding deterrent. - Nature (London) 232: 402-403 52 GRAIGNE, M., AHMED, S., MITCHELL, W.C. und HYLIN, J.W. (1985) Plant species reportedly possessing pest-control properties - an EWC/UH database. - Resource Systems Institute, EWC Honolulu, College of Tropical Agriculture and Human Resources, Univ. of Hawaii 53 GREENSTOCK, D. (1970) Garlic as a Pesticide. - HDRA Braintree, England 54 GRIST, D.H. und LEVER, R.J.A. (1969) Pests of Rice. - Longman, London 55 GRIST, D.H. (1953) Rice. - Longman, London 56 GTZ (1980) Post Harvest Problems. - Documentation of a OAU/GTZ Seminar, Lomé, March 1980 57 HAMILTON, C.C. und L.G. GEMMELL (1934) Some field tests showing the comparative efficiency of Derris, Pyrethrum and Hellebore powders on different insects. - J. Econ. Entomol. 27: 446-453 58 HANSBERRY, R. und C. LEE (1943) The yam bean, Pachyrrhizus erosus Urban, as a possible insecti­ cide. - J. Econ. Entomol. 36 (2): 351-352 59 HARPER, S.H., C. POTTER und E.M. GILLHAM (1947) Annona species as insecticides. - Ann. Appl. Biol. 34: 104-112 60 HERVE, D. (1981) La Muna como insecticida casero. - Minka (Peru), 7: 24-26

61 HILL, D. (1983) Agricultural insect pests of the tropics and their control. - 2nd Edition, Cambridge University Press 62 HOFFMANN, G.M. und SCHMUTTERER, H. (1983) Parasitäre Krankheiten und Schädlinge an landwirtschaftlichen Kulturpflanzen. - Ulmer Verlag 63 HOPPE, H.A. (1975/77) Drogenkunde. - 8. Aufl., 2 Bde. De Gruyter, Berlin 64 HORA, B. (1981) The Oxford Encyclopedia of Trees of the World. - Oxford Univer­ sity Press 65 HÜBNER, M. (1986) ex lit. 66 ILEIA (1985) ex lit. 67 IRRI (1985) Illustrated Guide to Integrated Pest Management in Rice in Tropi­ cal Asia. - International Rice Research Institute, Los Banos, Philippines

171 68 IRVINE, F.R. (1955) West African Insecticides. - Colonial Plant and Animai Products 5: 34-38 69 IWUALA, M.O.E. et al. (1981) Dcnnettia Oil, a potential new insecticide: Tests with adults and nymphs of Periplaneta americana and Zonocerus varirjgams. - J. Econ. Entomol. 74 (3): 249-252 70 JACOBSON, M. und D.G. CROSBY (1971) Naturally occuring Insecticides. - Marcel Dekker, Inc. New York 71 JACOBSON, M. (1975) Insecticides from Plants. A Review of the Literature, 1954-1971.- Agriculture Handbook No. 461, USDA, Washington DC

72 JACOBSON, M. (1984) Control of stored product insects with phytochemicals. - Proc. 3rd International Working Conference on Stored Products Entomology, Oct. 23-28, 1983 73 JAYASINCH, D.B. ( no year ) Admixture of inert dusts to cowpea seeds to prevent insect infe­ station. - Food Storage and Infestation Division Ministry of Indu­ stry and Commerce, Jamaica 74 JEX-BLAKE, A.J. (1950) Gardening in East Africa. Longmans, Green and Co. Ltd., London 75 JILANI, G. and H.C.F. SU (1983) Laboratory Studies on Several Plant Materials as Insect Repellents for Protection of Cereal Grains. - J. Econ. Entomol. 76 (1): 154-156 76 JOTWANI, M.G. and P. SCIRCAR (1965) Neem Seed as a Protectant against Stored Grain Pests infesting Wheat Seed. - Indian J. Entomol. 27 (2): 160-164 77 JOTWANI, M.G. and P. SCIRCAR, (1967) Neem Seed as a Protectant against Bruchid Callosobruchus macula- tus infesting some leguminous seeds. - Indian J. Entomol. 29 (1): 21-24 78 JUNG, K. (1938) Pflanzliche Insektizide (Pyrethrum, Derris, Mundulea, Lonchocar- pus, Tephrosia u.a.). - Tropenpflanzer 41: 431-443 79 KASHYAP, N.P., GUPTA, V.K. and A.N. KAUSHAL (1974) Mentha spicata, a promising protectant to stored wheat against Sitophilus oryzae. - Bull. Grain Techn. 12 (1): 41-44 80 KEMPSKI, D. (1940) Die insektiziden Pflanzen (Pyrethrum, Derris und Barbasco) Tropenreihe Nr. 45. - Tropenverlag Fr. W. Thaden, Hamburg 81 KEUDELL von, T. (1985) Der biologische Pflanzenschutz. - Heyne Verlag 82 KUMAR, A.R.V. and H.K. SANGAPPA (1984) A Note on the Performance of Plant Products in Control of Gram Caterpillar in Bengalgram. - Current Research 13 (4-6): 38-40 83 KUMAR, R. and M. SAMPSON (1982) Review of Stem Borer Research in Ghana. - Insect Sei. Appl. 3 (2/3): 85-88

172 84 LAL, K.B. (1955) Indigenous Insecticides. - Bull. Inst. Sei. India 4: 145-148 85 LAMBERT, J.D.H., J. GALE, J.T. ARNASON and B.J. PHILOGENE (1985) Bruchid Control with traditionally used insecticidal plants Hyptis spicigera and Cassia nigricans. - Insect Sei. Appl. 6 (2): 167- 170 86 LEAKEY, C.L. and J.B. WILLS (1977) Food Crops of the Lowland Tropics. - Oxford University Press

87 LENGERKEN von, H. (1932) Das Schädlingsbuch. - Brehm Verlag Berlin 88 LIKLIK BUK (1977) A Rural Development Handbook Catalogue for Papua New Guinea 89 LITSINGER J.A. and K. MOODY (1976) Integrated Pest Management in Multiple Cropping Systems. - In: SANCHEZ, P.A. and G.B. TRIPLET (Hrsg.) Multiple Cropping Special Publication No. 27, American Society of Agronomy, Madison Wisconsin 90 LITSINGER, J.A., E.C. PRICE and R.T. HERRERA (1980) Small farmer pest control practices for rainfed rice, corn and grain legumes in three Philippine provinces. - Philipp. Ent. 4 (1-2): 65-86 91 LÖTSCHERT und BEESE (1981) Pflanzen der Tropen. - BLV-Bestimmungsbuch 92 MacMILLAN, H.F. (1935) Tropical Planting and Gardening. - MacMillan & Co, London 93 MARIAPPAN, V. and R.C. SAXENA (1983) Effect of Custard-Apple Oil and Neem Oil on Survival of Nepho- tettix virescens and on Rice Tungro Virus Transmission. - J. Econ. Entomol. 76 (3): 573-576 94 MATHUR, A.C. and B.P. SAXENA (1975) Introduction of Sterility in Male Houseflies by Vapours of Acorus calamus L. Oil. - Die Naturwissenschaften 12: 576 95 MATTESON, P.C., M.A. ALTIERI and W.C. GAGNE (1984) Modification of small farmer practices for better pest management - Ann. Rev. Entomol. 29: 383-402 96 McKEEN, C. (1956) The inhibitory activity of extract of Capsicum frutescens on plant virus infections. - Canadian J. Botany 34: 891-903 97 MESSINA, F.J. and J.A.A. RENWICK (1983) Effectiveness of oils in protecting stored cowpeas from the cow- pea weevil. - J. Econ. Entomol. 76 (3): 634-636 98 METCALF, C.F., R.F. METCALF and W.F. FLINT (1962) Destructive and useful insects. - McGraw-Hill, New-York 99 MINA, P. und P. MUKASA (1985) Farmer turns to traditional method of preserving grain. - Daily Nation (Kenya), 21.3.1986, p. 13 100 MIRONOV, V.S. (1940) The use of Acorus calamus for insecticidal and repellent prepara­ tions. - Med. Parasit. (Moscow) 9: 409-410

173 101 MISHRA, R.C., D.B. MISHRA and P.R. GUPTA (1984) Effect of mixing the mentha powders with and giving oil-in-water emulsion dip to the chickpea on pulse beetle Callosobruchus chi- nensis Linn. - Bull. Grain Techn. 22 (1): 19-23

102 MORTON, J.F. (1981) Atlas of medical plants of Middle American Bahamas to Yucatan. - Charles C. Thomas Publ. USA 103 MUMFORD, J.D. and C.W. BALIDDAWA (1983) Factors affecting insect pest occurance in various cropping sy­ stems. - Insect Sei. Appl. 4 (1-2): 59-64 104 MURTHY, S.V., K.N. SHASHIKANTH und S.C. BASAPPA (1981) Studies on the antimicrobial and stimulatory factors of garlic. - J. Food Sei.and Techn. 18: 44-47 105 NASSEH, M.O. (1980) Zur Wirkung von Juvenoiden und Rohextrakten aus Allium sati­ vum L. auf Blattläuse und deren natürliche Feinde. - Dissertation Universität Giessen 106 NASSEH, M.O. (1980) Zur Wirkung von Rohextrakten aus Allium sativum L. auf Fraßak­ tivität und Metamorphose von Epilachna varivestis Muls. (Col., Coccinellidae). - Z. ang. Ent. 92: 464-471 107 NAYAR, S.L. (1955) Vegetable Insecticides. - Bull. Inst. Sei. India 4: 137-145 108 ORMACHEA, E.C.A. (1979) Usos tradicionales de la "Muna" (Minthostachys spp.) en aspectos fitosanitarios de Cusco y Puno. - Rev. per. Ent. 22 (1): 67- 69, Peru 109 PAGAN, C. and LOUSTALOT, A.J. (1949) Comparison of chemical values with the toxicological rotenone equivalent of Derris and Lonchocarpus roots.- J. Agric. Research 78 (7): 197-205 110 PANDEY, G.P., R.B. DOHAREY and B.K. VARMA (1981) Efficacy of some vegetable oils for protecting greengram against the attack of Callosobruchus maculatus. - Indian J. agric. Sei. 51 (12): 910-912 111 PEARSON, E.O. (1958) The Insect Pests of Cotton in Tropical Africa. - CIE, London, 355 pp. 112 PERIES, L. (1985) Special Announcement. - National Rural Conference, Sri Lanka 113 PERIES, L. (1985) ex lit., 114 PERIES, L. (1985) ex lit., 115 PERIES, L. (1986) Cattle urine as a substitute for agrochemicals. - National Rural Conference 116 PERKOW, W. (1968) Die Insektizide. Chemie, Wirkungsweise und Toxizität. - Alfred Hüthig Verlag, Heidelberg

174 117 PLANK, H.K. (1944) Insecticidal Properties of Mamey and other Plants in Puerto Rico - J. Econ. Entomol. 37 (6): 737-739 118 PLANT PROTECTION DIRECTORATE (Eds.), (no year) Treatment of cabbage and gboma against pests with neem seed extract. - Technical Leaflet Plant Protection, PPD/GTZ, Lomé/ Togo 119 PLANT PROTECTION DIRECTORATE (Eds.), (no year) The preservation of beans (cowpeas) with neem oil. - Technical Leaflet Plant Protection, PPD/GTZ, Lomé/Togo

120 PRANATA, R.I. (1985) Possibility of using turmeric (Curcuma longa L.) for controlling storage insects. - Biotrop Newsletter, Bogor/Indonesia 121 PROGRAMMA ALIMENTARIO NICARAGUENSE (Ed.), (no year) Control de plagas y enfermedades en huertos familares y colecti- vos, 3 p. (unpublished manuscript) 122 PUTTARUDRIAH, M.S. and K.L. BHATTA (1955) A preliminary note on studies of Mysore plants as sources of insecticides. - Indian J. Entomol. 17: 165-174 123 RADWANSKI, S.A. and G.E. WICKENS (1981) Vegetative Fallows and Potential Value of the Neem Tree in the Tropics. - Econ. Botany 35 (4): 398-414 124 RANKIN, J. (1984) Pesticide Pitch Flops. - The New Farm (USA), July/August, p. 36 125 RANKIN, J. (1985) ex lit., 26.11.1985 126 RANKIN, J. (1985) ABC's of Insect Pests. Lecture Notes. - Solusi College, Bulawayo/ Zimbabwe 127 RANKIN, J. (1986) ex lit., 6.1.1986 128 RATTANABAD SOCIAL & AGRICULTURAL EXTENSION CENTRE (Ed.) (1985) Progress Report No. 27, July/Sept. 85, Mirpurkhas/Pakistan 129 RAYMUNDO, S.A. and J. ALCAZAR (1983) Dusting with ashes to reduce leafminer fly damage on potatoes. - Appropriate Technology 10 (3): 17 130 REBOLDAD, M. (1986) ex lit., 31.3.1986 131 REHM, S. and G. ESPIG (1983) Die Kulturpflanzen der Tropen und Subtropen. - Ulmer Verlag, Stuttgart 132 RICHARDS, P. (1985) Indigenous Agricultural Revolution. - Hutchinson & Co, London 133 ROARK, R.C. (1947) Some promising insecticidal plants. - Econ. Botany 1: 437-445 134 ROSE, G.J. (1963) Crop Protection. - Leonard Hill (Books) Ltd., London

175 135 RUIZ, W. A. (1975) Fraccionamiento del aceite esencial del Minthostachys mollis (Muna) y su applicación en la inhibición del brotamiento de la papa - cultivar Mariva. - Universidad Nacional Agraria La Moli­ na, Tésis 136 SAXENA, R.C. (1981) Neem Seed Oil for Leaf Folder Control. - Plant Protection News (Philippines) 10 (2): 48-50

137 SCHMUTTERER, H. (no year) Pflanzenextrakte als umweltschonende Bekämpfungsmittel gegen Schadinsekten. - Inst. f. Phytopathologie und Angewandte Zoolo­ gie, Justus-Liebig-Universität Gießen 138 SCHMUTTERER H., K.R.S. ASCHER and H. REMBOLD (Eds.), (1981) Natural Pesticides from the Neem Tree (Azadirachta indica A. Juss). Proc. 1st Int. Neem Conf. (Rottach-Egern, 1980), 297 pp. 139 SCHMUTTERER, H. and K.R.S. ASCHER (Eds.), (1984) Natural Pesticides from the Neem Tree and other tropical Plants. Proc. 2nd Int. Neem Conf. (Rauischholzhausen, 1983), 587 pp.

140 SCHMUTTERER H., J. VON DER HEYDE and R.C. SAXENA (1985) Effects of neem derivatives on growth and fecundity of the rice pest Nephotettix virescens (Homopt. :Cicadellidae).- Z. Pfl'krank.- u. Pfl'schütz 92 (4): 346-354 141 SHEPARD, H.H. (1951) The Chemistry and Action of Insecticides. - McGraw-Hill Book Company, New York, London 142 SINGH, S.R. and H.F. VAN EMDEN (1979) Insect Pests of Grain Legumes. - Ann. Rev. Entomol. 24: 255-278 143 SINGH U.P., H.B. SINGH and R.B. SINGH (1980) The fungicidal effect of neem (Azadirachta indica) extracts on some soil-borne pathogens of gram (Cicer arietinum). - Mycologica 72: 1077-1093 144 SNOEK, H. (1984) Naturgemäße Pflanzenschutzmittel. - Pietsch Verlag 145 SOMBATSIRI K. and W. PATHUMCHARTPAT (1979) Some attempts to develop new insecticides from plant sources. - Proceeding of Seminar on "Sensible Use of Pesticides" in Japan on Nov.28 - Dec.3, 1978. Food and Fertilizer Technology Center, FFTC Book Series No. 14, Taiwan, 1979 146 SOMMERS, P. (1983) Low cost farming in the humid tropics: an illustrated handbook. Island Publishing House, Inc., Manila/Philippines 147 SPICKETT, R.G.W. (1955) The chemistry of some lesser known insecticides of plant origin. - Colonial Plant and Animal Products 5: 288-303 148 STEINER, K. (1982) Intercropping in Tropical Smallholder Agriculture with special Reference to West Africa. - Schriftenreihe der GTZ No. 137 149 SUBRAMANIAM, T.V. (1948/49) Sweet flag (Acorus calamus) - a potential source of valuable in­ secticide. - J. Bombay Nat. Hist. Soc. 48: 338-341

176 150 TEOTIA, T.P.S. and G.C. TIWARI (no year) Dharek drupes and leaves as protectants against Sitotroga cerea- lella Oliv, infesting wheat seeds. - Bull. Grain Techn., 9 (1): 7-12 151 THOMPSON, F.B. (1971) Plant Derivatives. - New Zealand J. Agric. 123 (6): 44 152 VAN DIJK, E. (1986) ex lit. 9.1.1986 153 VAN EMDEN, H.F. (1974) Pest Control and its Ecology. Studies in Biology No. 2. - E. Arnold (Publ.) Ltd. 154 VAN HUIS, A., R.S. NAUTA and M.E. VULTO (1982) Traditional Pest Management in Maize in Nicaragua: A Survey. - H. Veenman & Zonen B.V.-Wageningen 155 VAN DER WERF, E. (1985) Pest management in ecological agriculture. - AME Foundation, Groenekan/Holland 156 VAN DER WERF, E. (1986) A simple trap for mediterranean fruitfly (Ceratitis capitata). - AME Foundation, Groenekan/Holland 157 WALKER, H.G. and L.D. ANDERSON (1934) Notes on the use of Derris and Pyrethrum dusts for the control of certain insects attacking cruciferous crops. - J. Econ. Entomol. 27: 388-393 158 WATT & BREYER-BRANDWIJK (1962) The medicinal and poisonous plants of southern and eastern Africa. - E. & S. Livingstone Ltd., Edinburgh and London 159 WEGMANN, E. (1983) Holzaschen als wirksames Mittel zur Bekämpfung von Callosobru- chus maculatus in traditionellen Bohnenlagern Westafrikas. - Ge­ sunde Pflanzen 9: 229-234 160 YADAVA, R.L. (1971) Use of essential oil of Acorus calamus L. as an insecticide against the pulse beetle Bruchus chinensis L. - Z. angew. Ent. 68: 289-294 161 YEPSEN (Jr.), R.B. (1976) Organic Plant Protection. - Rodale Press, USA 162 YUN-TAI-QI and W.E. BURGHOLDER (1981) Protection of stored wheat from the granary weevil by vegetable oils. - J. Econ. Entomol. 74: 502-505

Additional references: 163 REDKNAP, R.S. (1981) Field trials using locally prepared insecticide (Neem-Azadi- rachta indica). - June-Sept. 1979 Banjul, Christian Counsil of the Gambia. 164 DAVIDSON and LYON (1979) Insect pests of farm, garden and orchard. 165 CARLIER, H. (1985) ex lit.

177 166 AHMED, S. and B. KOPPEL (1985) Plant extracts for pest control: Village-level processing and use by limited-resource farmers.- Paper presented at the AAAS annual meeting in Los Angeles, May 26-31, 1985 167 FALCON, L. A. (1975) Use of field-collected Insect Viruses for Pest Control.- In: SUMMERS, M., R. ENGER, L.A. FALCON and P. VAIL ( 1975TT Baculoviruses for Insect Pest Control: Safety Considerations.- Amer. Soc. f. Microbiology 168 RICHTER, H. (Ed.) (1961) Handbuch der Pflanzenkrankheiten.- Bd. VI, 3. Ausgabe, Verlag Paul Parey

178 INDEX

Acanthoscelides obtectus, 69, 70, 147 Bemisia tabaci, 62, 63, 95 acaricidal, 112 black carpet beetle, 103, 104, 106, 133 Acorus calamus, 111, 158 ff., 159 black maize beetle, 39 ff. Acrosternum hilaris, 109 Blissus hirtus, 109, 110 Acyrtosiphon pisum, 106 Bombyx laori, 104, 109 adzuki bean beetle, 70, 71, 87, 141, 142, 157, Bothynus maimon, 140 158. 160, 162, 166 Brevicoryne brassicae, 154 adzuki beans, 70 brown rice plant hopper, 21, 29, 30, 32, 33, Aeschrion excelsa, 103 ff. 81, 95, 135, 154 african army worn, 36, 38 bush dryer, 143 agro-ecosystems, 16 Busseola fusca, 17, 21, 41, 42, 43 agrotis, 95, 135 Agrotis segetum, 52, 54 cabbage aphid, 154 Agrotis ypsilon, 52, 53 cabbage looper, 56, 109 138, 139 Allium sativum, 89 ff., 35, 43, 48, 51, 59, cabbages, 56 61, 63, 65 cabbage worm, 95, 110, 113, 119, 121 american bollworm, 34, 35, 87, 95, 106, 125, Callosobruchus chinensis, 70, 71, 87, 157, 160, 135, 139 161, 166 Anasa tristis, 106 Callosobruchus maculatus, 70, 71, 95, 115, 164, Ancysta perseae, 109 165 andean lupine, 118 Calotropis procera, 61 annona, 81 ff., 51, 58, Capitarsia curbata, 148 Annona muricata, 81 ff., 83 Capsicum frutescens, 84 ff., 146 Annona reticulata, 81 ff. Carica papaya, 120 Annona squamosa, 81 ff., 82 cassava, 58, 73

antifeedant, 01, 84, 90f 94, 100, 118, 120, Cassia nigricans, 71, 147 153, 159 caterpillars, 85, 92, 104, 113, 115, 116, 121, antifertile, 159 124, 125 ants, 85, 93, 105 Ceratitis capitata, 66, 68, 87, 95, 160 Aphididae, 50, 51 Ceratitis cosyra, 66, 67 aphids, 50 ff., 81, 85, 91, 92, 95, 100, 104, Ceratitis rosa, 66, 67 105,109, 111, 113, 114, 119, 121 cereals, 39, 72 Aphis gossypii, 87 Cerotoma ruficornis, 92 Aphis rumicus, 109 chilli, 51, 71, 84 ff., 146 army worms, 36 ff., 87, 91, 99, 109,, 115, 116, chilli-mixture, 122, 123 119, 121, 135, 139, 154, 160 Chilo partellus, 41, 42, 95 army worm repellent, 39, 140 Chilo polychrysus, 25 army worm traps, 39, 135 Chilo suppressalis, 25, 27 Ascya monuste, 92, 93 chrysanthemum aphid, 81 ashes, 127 ff. Chrysanthemum cinerariaefolium, 99 ff., Aspodydia, 100 Chrysodeixes chalsites, 87 asian corn borer, 154 citrus, 38, 50, 58, 64, 66 Attagenus piceus, 104, 106, 133 citrus red mite, 154 Aulacophora foveicollis, 82, 83 cockroaches, 93, 109, 119, 121 avocado, 60, 63 cockroach plant,-65, 68, 118 avocado lace bug, 109 codling moth, 104, 106, 119, 121 Azadirachta indica, 94 ff., 151 ff. coffee, 52, 60, 66 coffee bugs, 100 bactericidal, 90 coffeerust, 121 Bagrada, 109 Colias philodice, 139 baits, 129, ff. collards, 60 bakulo-virus, 138 Colorado beetle, 85, 91, 95, 100, 104, 119 bananas, 66 contact poison, 81, 87, 92, 110, 103, 106, 108, Barringtonia asiatica, 123 118, 120, 153 basil, 118 corn earworm, 139, 154 bean bruchids, 69, 70, 119 cotton, 34, 38, 56, 62, 64 bean fly, 20, 21, 44, 45 cotton leafworm, 37, 38 beans, 34, 44, 48, 60, 62, 69 cowpea beetle, 70, 71, 95, 115, 164, 165 bean thrips, 60 cowpeas, 46 beetle larvae, 111 cow urine, 28, 43, 124 179 Crocidoloaia binotalis, 87 fuaigant, 84 crop rotation, 18 fungi, 124, 127 crotalaria, 76, 118 fungicidal, 90, 94, 112, 118, 120 Crotalaria ochroleuca, 118 Fusariua oxysporua, 98 croton oil tree, 118 136 Croton tigliua, 118, 123 garlic, 35, 43, 48, 51, 59, 60, 61, 63, 65, CryptopHlebia leucotreta, 64, 91 89 ff., 90 cucuaber beetle, 92, 127 goat dung, 76, cucurbits, 46, 48, 50, 56, 58, 62, 66 grain, 72, 73, 75, 76 Curcuma doaestica, 114 ff., 115, 162 grain borer, 115 custard apple, 81 ff. grain weevil, 113, 154, 156, 162, 165 cutwora bait, 54, 129 grasshoppers, 82, 96, 99, 100, 109, 110, 119 cutworas, 18, 52 ff., 95, 135 greasy cutwora, 52, 53 Cydia aolesta, 133 green bugs, 82 Cydia poaonella, 104, 106 green rice leaf hopper, 29, 30, 32, 82, 95, 135, 154 dacus, 87 green stink bug, 109 Oacus Cucurbitae, 66, 67, 160 growth-inhibiting, 94, 118, 153 Dacus dorsalis, 66, 160 guavas, 66 darkheaded rice stea borer, 25 dead-heart-effect, 28, 40, 42 hairy chinch bug, 109, 110 dennettia, 118 Kaplophyton cisicidua, 65, 68, 118 dennettia oil, 71, 164 heafc-treataent, 74, 166 Dennettia tripetala, 118 Heliothis araigera, 34, 35, 87, 95, 106, 125, derris, 33, 35, 48, 49, 51, 54, 58, 61, 68, 135, 139 86 ff., Heliothis virescens, 34 Derris elliptica, 86 ff., Heliothis zea, 34, 139, 154 Derris aalaccensis, 86 ff. Hellula undalis, 95 Derris uliginosa, 86 ff. Heteronychus, 39 ff. derris-mixture, 123 Heteronychus arator, 39, 40 desert locust, 95 Heteronychus consiailis, 39, 40 Diabrotica bivittata, 92 Heteronychus licas, 39, 40 dianondback aoth, 17, 55, 56, 58, 81, 87, 92, Hoplocaapa, 104 93, 95, 104, 121 hopperburn, 31 Diaphania hyalinata, 92, 104, 106, 109 horse-radish tree, 120 Diatraea lineolata, 20 houseflies, 106 diversification, 17 Hyptis spicigera, 71, 147 dock aphid, 109 drying,. 142 ff. insecticidal, 81, 84, 87, 90, 92, 94, 100, 103, eggplants, 46, 62, 78 108, 112, 114, 118, 120, 153, 157 159 egyptian cotton leafworm, 37, 36 insecticidal plants, 81 ff., 146 ff. Enpoasca devastans, 100 iaported cabbage wora, 85, 91, 92, 100, 106, Eapasca fabae, 48, 49, 95, 109, 110 139, 154 Epilachna chrysoaelina, 95 Epilachna varivestis, 46, 47, 91, 95, 104, jassids, 19, 20, 21 eucalyptus, 71, 79, 119 Jatropha curcas, 123 Epitrix, 17 european corn borer, 106, 109, 119, 121 kasahui, 113, 114 kerosene, 33 fall araywora, 17, 20, 95 kerosene-soap-eaulsion, 59, 63, 140 false codling Both, 64, 91 khapra beetle, 72, 73, 91, 95, 145, 152, 160 field hygiene, 21 fish poison, 88, 118 land formation, 18 flea beetle, 95, 100, 109, 113, 121 Lantana canara, 79 fleas, 160 large cabbage worn, 55, 56, 95, 100, 139, 154, flour preparation, 51, 59, 139 160 fruit flies, 66 ff. larvicidal, 81, 103, 148 fruit fly traps, 65, 68, 129 ff., 131, 132 leaf bug, 109 fruits, 64 ff. leaf-eating caterpillars, 55 ff., 109

180 leaf miner, 95, 90, 104, 113, 129, 136 milk-preparation, 139 leaf miner fly, see leaf miner millet, 25, 30, 41 leaf miner fly trap, 136 Minthostachys glabrescens, 148 ff. Lecanium , 63 Hinthostachys mollis, 148 ff. leeks, 60 mites, 58 ff., 92, 95, 104, 106, 113, 115, 124, legumes, 34, 30, 44, ff., 56, 50, 69, 70 125, 139 Leptinotarsa decenlineata, 65, 91, 95, 100, mixed farming, 17 104 mixtures, 122 ff. leptocorisa acuta, 123 molluscicidal, 118 Leptoglossus australis, 109 Moringa oleifera, 120 lesser grain borer, 73, 74, 95, 115, 152, 154, mosaic virus, see virus 160, 162 mosquitos, 119 Leucinodes orbonalis, 100 »una, 79, 148 ff. light traps, 28, 33, 35, 39, 40, 43, 54, 133 Murraya paniculata, 140 ff. 143 Myzus persicae, 104, 109, 154 liriomyza 95, 128 liriomyza huidobrensis, 128, 136 natal fruit fly, 66, 67 Locusta migratoria, 95, 154 natural rhythms, 19 lonchocarpus, 61 neem, 28, 33, 35, 39, 43, 48, 51, 58, 59, 61, lucerne butterfly, 139 68, 71, 72, 74, 76, 77, 94 ff., 151 ff. Ludius, 148 nematicidal, 90, 92, 94, 103, 118 Lupinus mutabilis, 118 nematodes, 18, 98 Lycopersicon esculentum, 120 Nephotettix nigropictus, 29, 32, 135 lycosa, 17 Nephotettix virescens, 32, 82, 95, 154 Lygus, 100 Nicotiana glutinosa, 111 ff. Nicotiana rustica, 111 ff. Macrosiphoniella sanborni, 81 Nicotiana tabacum, 111 ff., Macrosiphum euphorbiae, 82 Nilaparvata lugens, 29, 32, 81, 95., 135, 154 maize, 25, 30, 34 ff., 46, 52, 64, 75, 76 maize stalk borer, 17, 21, 41 Ocimum basilicum, 118 maize stem borers, 22, 41 ff. Oidium 127 'maize weevil, 75, 119 oil seeds, 72 mangoes, 66 okra, 48, 62 manuring, 19 onions, 60 Maaeea americana, 92 ff. onion thrips, 60, 61, 106 Mammestra brassicae, 95 Ophiomyia reticulata, 100 mamney, 58, 77, 92 ff. oriental fruit fly, 66, 160 Handuca quinquemaculata, 135 oriental fruit moth, 106 Manduca sexta, 106 Orseolia oryzae, 135, 154 mango fruit fly, 66, 67 Oryzaephilus surinamensis, 82 Margaronia indica, 87 Ostrinia furnacalis, 154 mealy bugs, 105, 124, 125 Ostrinia nubilalis, 106, 109 mediteranean fruit fly, 66, 68, 87, 95, 160 Helanagromyza phaseoli, 44, 45 Pachyrrhizus erosus, 120 He 1ia azedarach, 99, 153 ff., Panonychus citri, 154 Melitta Cucurbitae, 106 papayas, 60, see also melon tree melon aphid, 87 Papilio demodocus, 95, 97 melon beetles, 96 passion fruit, 66 melon fruit fly, 66, 67, 160 pea aphid, 106 melon tree, 120 peach aphid, 104, 109, 154 melons, 66 peaches, 66 melon worm, 92, 104, 106, 109 peanuts, 38, 60, 72 Mentha spicata, 157 ff. peas, 60 mexican bean beetle, 46, 47, 91, 95, 104, 119, Persian lilac, 28, 99, 153 ff,, 154 121 Philaenus leucophthalmus, 109 mexican fruit flies, 119 Phthorimaea operculella, 17, 78, 148 nice (trap for ...), 136 ff. Phymatocera aterrima, 104 migratory locust, 95, 154 Phytium debangemum, 121 mildew, 121, 127 Picrasma excelsa, 103 ff.

181 Picris brassicae, 55, 56, 95, 100, 139, 154, Scrobipalpula, 148 160 Sesaaia calamitis, 17, 21, 41, 42, 43 Pieris rapae, 56, 91, 92, 100, 106, 139, 154 Sesamia inferens, 25, 26 pink stalk borer, 41, 42 silkworm, 104, 109, 119 Plutella xylostella, 17, 55, 56, 58, 81, 87, Si tophilus granarius, 115, 162, 165 92, 95, 104 Sitophilus oryzae, 76, 77, 85, 92, 95, 115, 157, Podagrica uniforma, 95 160, 165 potato aphid, 82 Sitophilus zeamais, 75 potatoes, 46, 48, 62, 78, 149 ff. Sitotroga cerealella, 156 potato flea beetle, 17 snails, 119 potato jassids, 48, 49, 95, 109, 110 soap-solution, 33, 51, 59, 61, 140 potato pit, 150 Sogatella furcifera, 29, 82, 95 potato tuber moth, 17, 78, 119, 148 soil tillage, 20 Pratylenchus, 98 solar dryer, 144 Premnotrypes solarti, 148 sorghum, 34, 38, 41, 75 purple stalk borer, 25, 26 sorghum shootfly, 21 pyrethrum, 33, 35, 39, 43, 48, 49, 54, 58, 59, soursop, 81 ff., 83 61, 63, 65, 99 ff., 101 soya beans, 70 Pyricularia oryzae, 87 spearmint, 71, 77, 157 ff. spices, 72 quassia, 51, 58, 103 ff. spider mites, 119 Quassia anara, 103 ff. spittle bug, 109 Spodoptera, 36 ff., 135, 154 rats, {trap for ...J, 136 ff. Spodoptera abyssina, 109 Recilia dorsalis, 29, 32 Spodoptera eridania, 109 red mites, 106, 139 Spodoptera exempta, 36, 38 red pumpkin beetle, 82, 83, Spodoptera frugiperda, 17, 20, 39, 95 repellent, 81, 94, 87, 90, 92, 94, 100, 108, 112, Spodoptera littoralis, 37, 38 114, 118, 120, 148, 153, 157, 159 Spodoptera litura, 37, 38, 87, 91, 99, 115, 116, resistance, 21 139, 160 respiratory poison, 112 spotted stalk borer, 41, 42, 95 Rhizoctonia solani, 98 squash bug, 106, 119 Rhizopertha dominica, 73, 74, 95, 115, 154, 160, squash vine borer, 106 162 stalk borers, 19, 20, 21, 25 ff., 41 ff., 113, 123 rice, 25 ff., 38, 41, 75, 76 stem borers, see stalk borers rice black bugs, 135 stink bug, 109, 121 rice flour beetle, 115, 157 stomac poison, 81, 84, 87, 92, 103, 106, 108, 118 rice gall nidge, 135, 154 120, 153 rice hoppers, 29 ff. storage, 69 ff. rice stalk borers, see rice stem borers storage protection, 141 ff. rice stem borers, 19, 25 ff., 95, 135 striped rice stem borer, 25, 27 rice weevil, 76, 77, 85, 92, 95, 115, 119, 152, sugar-cane, 25, 39, 41 157, 158, 160, 165 sunflowers, 34, 62, 66 rotendicidal, 108 sweet flag, 68, 71, 72, 74, 77, 111, 158 ff., 159 rotenone, 61 sweet potatoes, 48, 56, 58 rust, 113, 114, 121, 127 sweetsop, 81 ff., 82 ryania, 35, 43, 63, 68, 106 ff. Ryania speciosa, 106 ff. taro, 58 tent caterpillars, 110 sabadilla, 49, 63, 107 ff., 108 Tephroclystia absinthieta, 110 salad, 66 Tephrosia, 61 sand, 71 Tetranychus, 58, 59, 106 saw-toothed grain beetle, 82 thrips, 20, 60 ff., 109, 113 Schistocerca gregaria, 95 Thrips tabaci, 60, 61, 106, 110 Schoenocaulon officinale, 107 ff., 108 thundergod vine, 120 Scirpophaga incertulas, 25 ticks, 90, 92, 118, 153 Scirpophaga innotata, 25 tobacco, 28, 33, 34, 38, 39, 40, 43, 46, 49, Sclerotina sclerotiorum, 98 51, 52, 54, 58, 61, 62, 63, 65, 78, 111 ff., Sclerotium rolfsii, 98 tobacco horn worm, 106

182 tomatoes, 34, 38, 48, 60, 66, 78, 120 tonato hornworm, 135 traps, 129 ff. Triboliun, 115 Triboliu# castaneunt, 157 Trichoplusia ni, 56, 109, 138, 139 Tripterygium wilfordii, 120 Trogoderma granarium, 72, 73, 91, 95, 160 turmeric, 77, 114 ff., 162 turnip moth, 52, 54

Urentinus echinus, 83 urine, 51, 59, (see also cow urine)

variegated grasshopper, 22, 95, 119 vegetable oils, 71 vegetables, 34, 38, 39, 50 ff. viroid, 84 virus, 31, 50, 54, 60, 62, 85, 113, 114, 124, 125, 138, 139 yam bean, 48, 51, 58, 120 yans, 39 yellow paddy stem borer, 25

zigzag rice leaf hopper, 29, 32 Zonocerus variegatus, 22, 95 184 CURRENT ACTIVITIES

Prospects for the further developments of "according to nature-met­ hods" and current activities:

At the present time research and development is proceeding along a number of different lines from universities and international re­ search institutions to groups of farmers and local education cen­ tres. Each has a different approach and emphasis. As set out be­ low, some international organisations are principally concerned with natural methods of plant protection at the small farmer or village level. Those who seek contacts in specific tropical and subtropical countries or require information about particular prob­ lems can approach the AGRECOL INFORMATION CENTRE in CH-4438 LANGENBRUCK/Switzerland.

1. EWC (East-West Center), 1777, East West Road, HONOLULU, Ha­ waii, 96848, USA. Within the framework of the Botanical Pest Con­ trol Programme, a comprehensive programme of research into insec- ticidal plants is being carried out. EWC is interested in coopera­ ting with individuals or groups who want to make investigations in the practical field. Contact Saleem Ahmed.

2. GATE (German Appropriate Technology Exchange), Postfach 5180 D-6236 ESCHBORN, W-Germany. In 1985 GATE began a programme of investigating insecticidal plants which would be suitable for use by small farmers. GATE is interested in cooperating with similarly- interested bodies and farming groups. Thus, results can be ex­ changed and evaluated. Contact Klaus Rudolph.

3. ENDA-PRONAT, B.P. 3370, DAKAR/Senegal. Pronat has carried out research into the effect of pesticides in Senegal. It is also working for the introduction of non-chemical methods of plant protection. Contact: Paul Germain.

185 4. AGRECOL (AGRibusiness and ECOLogy), P.O. Box 168, AD-2040 ZANDVOORT/The Netherlands, is an active member of the Stichting Mondiaal Alternatif/MA. The main aims are to explain and distribute informations about the consequences of the increasing use of chemical pesticides and to built up an international co-operation to develop alternatives.

5. VFLU (Verein zur Förderung von Landwirtschaft und Umwelt­ schutz in der Dritten Welt - Organisation for the Promotion of Agriculture and Environmental Protection in the Third World), Mainzer Str. 14, D-6501 STADECKEN-ELSHEIM 2/W-Germany. The association supports an organic crop protection project in Nicara­ gua where the bacillus thuringensis and neem are investigated for local use. Contact Carsten Hellpapp or Volker Stabel.

6. ELC (Environment Liaison Centre), P.O. Box 72 461, NAIROBI/- Kenya. A member of PAN (Pesticide Action Network) and concerned with questions of environmentally sound agriculture. Luis Malaret has published an NGO guide book "Safe ways to fight pests" which deals with safer methods of chemical pest control and contains a reference list of relevant literature and contacts. It can be pur­ chased at the ELC for US$ 7.

7. ILEIA (Information Centre about Low External Input Agriculture) P.O. Box 64, 3830 AB LEUSDEN/The Netherlands, issues a quarterly newsletter and has considerable informations on Integrated Pest Management.

An important address for further information on storage protection is:

8. TPI (Tropical Products Institute), 56/62 Gray's Inn Road, LONDON WC1X8LU/England, is an important source of information about the protection of crops in store. It has published a report entitled "The Use of Plants and Minerals as Traditional Protectants of Stored Products", report of the TPI G 138, vi+32 pp. by P. Golob and D.J. Webley (1980). TPI answers queries gladly and runs a series of instruction courses.

186 9. VITA, Suite 200, 1815, North Lynn Street, P.O. Box 12438, ARLINGTON, Virg. 22209-8438/USA. Carl Linblad and Laurel Drüben have issued a three part publication "Preserving Grain for Sto­ rage" which deals comprehensively with pests encountered in sto­ rage and basic methods of protection. It gives very worthwhile technical information on silo construction and hygiene, but has little to say about alternatives to chemicals.

187 REQUEST FOR INFORMATION

Please send us information about natural methods of crop protec­ tion not included in this book with which you are familiar, and which have proved to be successful in your experience.

Kindly: * Give as many details as possible, always including weights and/or volumes.

* Send line drawings and/or good photographs.

* When known, give the scientific name of plants and insects in addition to the common or local name, or send preserved specimens (flowers, fruits and leaves).

* Send your contributions to: Gaby Stoll, Bühlengasse 2, 7609 HOHBERG, West-Germany.

With your help it could be possible to expand this book gradually to make it a comprehensive guide to natural crop protection. We shall, of course, acknowledge all contributions in future editions. Please accept our grateful thanks in advance.

188