Insect Pests of Mubgbean and Their Control
N.S. Talekar Entomologist
Asian Vegetable Research and Development Center Shanhua, Tainan, Taiwan
1. Introduction
Mungbean, Vigna radiata (L.) Wilczek, is a major legume crop grown widely in south- and southeast Asia, mostly on small-scale family-owned farms. This low input, short duration crop is prized for its seeds, which are high in protein, easily digested, and consumed as food. It is an important source of dietary protein, especially in Indian Subcontinent where consumption of animal protein is very low. Because of its short duration, mungbean is easily adopted to multiple cropping system in the drier and wanner climates of lowland tropics and subtropics. Despite its short duration, large number of insect pests attack mungbean from soon after germination to harvest limiting the yield and some pests destroy seeds in storage (Table 1). Since mungbean is grown mainly in the tropical climates, insect pests play important role in the economic production of the crop.
The insect pests that attack mungbean can be classified based on their appearance in the field as it relates to the phenology of mungbean plant. They are thus: 1. stem feeders, 2. foliage feeders, 3. pod feeders, and 4. storage pests. This classification is convenient in judging the economic importance of the pest, especially their influence on seed yield, and in devising control measures. In this chapter, therefore, the pests will be discussed according to this chronological order.
The major stem feeders, especially in seedling stage are the agromyzid flies, so call beanflies, consisting of at least three species. In India the girdle beetle, Oberia brevis (Swedenbord), a major pest of soybean, sometimes attack mungbean. Its damage, however, is minor and localized. Large number of foliage feeders belonging to orders Lepidoptera and Coleoptera feed on the foliage of mungbean and several other related legumes. These include armyworms (Spodoptera exigua (Huebner), Spodoptera litura (F.)) hornwonn; (Agris convolvuli (L.)), cotton leafhopper (Amrasca biguttula biguttula Nishida), Bihar hairy caterpillar (Spilosoma obliqua (Walker)), Epilachna spp. and flea beetles, grasshoppers etc. Most of these insects are highly polyphagous and feed on wide variety of legumes and non- legumes. Their damage to mungbean is highly localized and most case minor. However, two groups of insects, aphids especially black bean aphids, Aphis craccivora Koch, and thrips belonging to genus Megalurothrips are especially -10 1- damaging to mungbean and other related legumes They will be discussed here. Major pod feeders are the hemipteran bugs especially the'most widespread southern green stink bug, Nezara viridula L., and two species of lepidopterous podborer, the Maruca podborer, Maruca testulalis (Geyer) and Limabean podborer Etiella zinckenella Tretsche. Although other species such as the tomato fruitworm, Helicoverpa armigera (Huebner), Asiatic cornborer, Ostrinia furnacalis (Guenee) and others attack mungbean and other legumes, these legumes are secondary or minor hosts of these pests. Information on these pests can be more easily obtained from study on other crops. The storage pests include species of bruchids belonging to genus Callosobruchus are primary pests of mungbean, especially on stored seeds. Their control is especially important to reduce avoidable losses. - 102-
Table 1. List of insect pests recorded on mungbean
Pest species Order: Familya Plant Reference parts attacked b
Acrocercops phaseospora Meyr. Lep: Gracillarridae L Vyas, 1978 Actinomorpha psittacina (Haan) Ort: Acrididae L Litsinger et al., 1978 Agris convolvuli L Lep: Sphingidae L Nayer et al. 1976 Alcidodes collaris Pasc Col: Curculionidae S Nair, 1975 Alcidodes fabrici F. Col: Curculionidae S Nair, 1975 Amsacta albistriga Walker Lep: Arctiidae L Anonymous, 1970 Amsacta lactinea (Cam) Lep: Arctiidae L Subba Rao et al., 1976 (= Estigmene lactinea) Lep: Arctiidae Amsacta roorei Butler Lep: Arctiidae L Lai, 1985 Anarsia ephippias Meyr. Lep: Gelechidae L Fletcher, 1914 Anoplocnemis phasiana F. Hem: Coreidae P Nayer et al. 1976 Antricarsia irrolata Lep: Noctuidae L Nayer et al., 1976 Aphis craccivora Koch Hem: Aphididae L, S, F, P Nayer et al. 1976 Apion ampulum Fst. Col: Apionidae Subramaniam, 1959 Aulocophora similis Oliver Col: Chrysomelidae P Litsinger et al., 1978 Autographa nigrisigna Walker Lep: Noctuidae L Nair, 1975 Bemisia tabaci Gennadius Hem: Aleyrodidae L Nene, 1972 Bruchus phaseoli Gyllanhae Col: Bruchidae Sd Anonymous. 1970 Caliothrips indicus (Bagnall) Thy: Thripidae L, F Lal et al. 1981 Callosobruchus analis (F.) Col: Bruchidae Sd Raina, 1970 Callosobruchus chinensis (L.) Col: Bruchidae Sd Gujar & Yadava, 1978 Callosobruchus maculatus (F.) Col: Bruchidae Sd Nair, 1975 Catochrysops cnejus F. Lep: Lycaenidae F, P Litsinger et al., 1978a Ceococcus coffeaie Green Hem: Coccidae L, S Subba Rao et al. 1976 Ceratina binghanzi Ck1l. Hym: Apidae Nayer et al., 1976 Chauliops fallax Scott Hem: Lygaeidae L, P Rawat and Sahu, 1968 ------103-
Pest species Order: Family Plant Reference parts attackedb
Chrotogonus trachypterus Blanch Ort: Acridiidae L, F, P Lal 1983 Chrysodeixis chalcites (Esper) Lep: Noctuidae L Litsinger et al., 1978a Clavigralla gibbosa (Spinola) Hem: Coreidae L, P Nayer et al. 1976 Colemania sphenarioides Bol. Ort: Acridiidae L, F, P Nair, 1975 Coptosoma cribaria F. Hem: Pentatomidae P Nayer et al. 1976 Cydia ptychora Meyr. Lep: Pyralidae P Lal et al. 1980 Cvrtozemia coqnata Marshall Col: Curculionidae L Pal, 1972 Diachrysia orichalcea (F.) Lep: Noctuidae L Babu et al., 1978 Empoasca biguttula Shiraki Hem: Jassidae L Litsinger et al., 1978a Empoasca kerri Pruthi Hem: Jassidae L Pruthi, 1940 Empoasca moti Prughi Hem: Jassidae L ' Chabra et al. 1981 Empoasca terminalis Distant Hem: Jassidae L Chabra et al. 1981 Epilachna philippinensis Dreke Col: Coccinelidae L Litsinger et al., 1978a Epilachna spp. Col: Coccinelidae L Lal et al., 1980 Etiella zinckenella Tretsche Lep: Pyticidae P Litsinger et al., 1978a Eublema hemirhoda Walker Lep: Noctuidae L Nayer et al., 1976 Euchrysops cnejus F. Lep: Lycaenidae P Nayer et al. 1976 Eucosma melanaula Meyr. Lep: Eucosmidae L Nayer et al. 1976 Euproctis scintillans (Walker) Lep: Lymantridae L Subba Rao et al., 1976 Gracillaria soyella V.D. Lep: Gracillariidae L Nair, 1975 Helicoverpa armigera Huebner Lep: Noctuidae L, P Nayer et al., 1976 Homona coffearia Nietner Lep: Torticidae L Litsinger et al., 1978a
Lampides boeticus L. Lep: Lycaenidae P Nayer et al. 1976 Lamprosema indicata F. Lep: Pyralidae L Nair, 1975 Leucopholis irrorata (Chev.) Col: Scarabaeidae R Litsinger et al., 1978a Locusta migratoria malinensis (Meyer) Ort: Acrididae L Litsinger et al., 1978a Longitarsus manilensis Weise Col: Chrysomelidae L Litsinger et al., 1978a ------10 4-
Pest species Order: Family Plant Reference parts attackedb
Luperodes sp. Col: Chrysomelidae Lal et al., 1980 Madurasia obscurella Jacoby Col: Chrysomelidae L Menon & Saxena, 1970 Maruca testulalis (Geyer) Lep: Pyralidae F, P Nair, 1975 Megalurothrips distalis (Karny) Thy: Thripidae L, F Lal et al. 1981 Megalurothrips usitatus (Bagnall) Thy: Thripidae L, F Chang, 1992 Melanagromyza sojae (Zehntner) Dip: Agromyzidae S Chiang & Talekar, 1980 Mylabris pustulata Th. Col: Meloidae F Nayer et al., 1976 Myllocerus maculosus Desbr. Col: Curculionidae Srivastava et at., 1977 Mythimna separata (Walker) Lep: Noctuidae L Litsinger et at., 1978a Nacoleia vulgalis GN. Lep: Pyralidae Nair, 1975 Nezara viridula L. Hem: Pentatomidae P Nayer et a1.1976 Oberea brevis S. Col: Cyranbycidae S Nair, 1975 Ophiomyia centrosematis (de Meijere) Dip: Agromyzidae S Chiang & Talekar,1980 Ophiomyia phaseoli (Tryon) Dip: Agromyzidae S. Saxena, 1973 Ostrinia furnacalis (Guenee) Lep: Pyralidae S, P Talekar et at., 1991 Oxya velox F. (= O. chinensis Thumb.) Ort: Acridiidae L, F, P Singh & Singh 1977 Pachytychius mungonis Marshall Col: Curculionidae Fletcher 1917 Phaneropteraftrcifera Stal Ort; Tettigoniidae L Litsinger et at., 1978a Phytomyza horticola Gour Dip: Agromyzidae L Singh & Singh, 1978 Plusia chalcytis F. Lep: Noctuidae L Nair, 1975 Plusia daubei F. Lep: Noctuidae L Nair, 1975 Plusia peponis F. Lep: Noctuidae L Nair, 1975 Riptortus fiuscus F. Hem: Coreidae P Nayer et at., 1976 Riptortus linearis F. Hem: Coreidae P Nayer et al., 1976 Riptortus pedestris F. Hem: Coreidae P Nayer et al., 1976 Spilosoma oblique Walker Lep: Arctiidae L Nair, 1975 Spodoptera exigua (Huebner) Lep: Noctuidae L Singh & Singh, 1978 ------
Pest species Order: Fainilya Plant Reference parts attacked b
Spodoptera litura (F.) Lep: Noctuidae L Nair, 1975 Stonzopteryx subsecivella (Zeller) Lep: Gelechiidae L Litsinger et al., 1978a Sylepta sabinusalis Walker Lep: Pyralidae L Litsinger et at., 1978a Taeniothrips longistylus Karny Thy: Thripidae L, F Litsinger et at., 1978a Tricentrus bicolor Dist. Hem: Membracidae L, F Nayer et al., 1976 Zaphanera publica (Singh) Hem: Alyrodidae L, P Nayer et at., 1976 a Order: families: Col = Coleoptera, Dip = Diptera, Hem = Hemiptera, Hym: Hymenoptera, Lep = Lepidoptera, Ort = Orthoptera, Thy = Thysanoptera bPlant parts attacked: F = flowers, L = leaves, P = pods, R = roots, S = stem, Sd = seeds - 105-
2. Stem feeders
Beanflies
Three species of flies belonging to family Agromyzidae are important pests of mungbean and several other legumes throughout Asia. The species that attack mungbean are: Ophiomyia phaseoli (Tryon); Melanagromyza sojae (Zehntner) and Ophiomyia centrosematis (de Meijere). Their importance lies in the fact that I they attack plant soon after germination when it is most vulnerable to insect pest attack. If these pests are not controlled, at times the whole -crop can be destroyed or severely damaged requiring re-sowing of the crop. The nature of damage and seasonality of these agromyzids is similar. Therefore same control measures can combat all three pests. The biology, nature of damage and control measures are described in details in this section.
Ophiomyia phaseoli
Morphology and Identification
Identification of adults of O. phaseoli in the field difficult because they do not cause significant damage; they are agile and thus difficult to observe in the field and, to an inexperienced person, they can be easily confused with adults of other agromyzid species since at least two other species of agromyzids (Ophiomyia centrosematis and Melanagromyza sojae) that attack most economically important legumes simultaneously with O. phaseoli. Spencer (1973) gives details of morphology of adults of several agromyzids, including O. phaseoli. For practical purpose, therefore, it is much easier to identify O. phaseoli and other agromyzids by observing larvae and pupae especially anterior and posterior spiracles of these immature stages (Figure 1). Besides morphological differences, their feeding and oviposition sites within the host plants give a fairly accurate idea of their identity (Figure 2). These details are explained by Talekar (1990).
Ophiomyia phaseoli larva is a cortex feeder and pupates in the cortex mostly at root shoot junction. Sometimes pupae can be seen sticking under the membranous epidermis (Talekar, 1990). In all plants the oviposition takes place in unifoliate or early trifoliate leaves. A biotype of this insect in Indonesia lays eggs in cotyledons of soybean. Both larvae and pupae can be identified by observing their spiracles. In both stages anterior spiracles are small, with a circle of six minute bulbs. Posterior spiracles closely adjoin on the conical projections usually with about 10 minute bulbs. The puparium is pale yellow, straw colored or light brown. .' -106-
A closely related species, Ophiomyia spencerella (Greathead) cannot be easily distinguished from O. phaseoli in its larval or even adult stages. The posterior spiracles of larvae or pupae are identical in both species, except that immatures in O. spencerella have 9.9 ± 1.2 openings on an average as against 10
Ophiomyia phaseoli Ophiomyia centrosematis Melanagromyza sojae Larva Last instar
F a Anterior I a ;la vat *: sp irac l es
iC Posterior
s p iracles a;
Pupa : ;.
Anterior ae*.:...... *0*. . spiracles **::
Posterior spiracles
Figure 1. Morphological characters of immature stages of three important species of agromyzids attacking mungbean in Asian tropics. -107-