Pink Bollworm
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Authors Crop Protection Folder Series: 7 of 11 Prediction Criteria: insecticidal spray is arrived at using the male catches in English Version 0 Dr. S. Vennila Maximum temperature greater than 33 C, morning the traps. If the moth catches exceed eight per trap for Dr. V. K. Biradar relative humidity less than 70 %, evening relative three consecutive days an insecticidal spray in the field is Division of Crop Protection humidity greater than 40 % during the standard weeks of desired. When much of the bolls on the plants are 20-25 Central Institute for Cotton Research 40, 41 and 43, and less than 12°C minimum temperature days old during October end and November insecticidal Nagpur Mr. M. Sabesh between 48 and 49, respectively result in P. gossypiella protection is a must. In the absence of pheromone traps, Central Institute for Cotton Research (R. S.) severity. assessment of pink bollworm damage should be based on Coimbatore Pest Management Options: destructive sampling (boll cracking method) and & Know Your Cotton Insect Pest Cultural control plays a key role in keeping down the chemical spray should be taken up when two live larvae Dr. O. M. Bambawale PINK BOLLWORM number of pink bollworm carry-over between cotton National Centre for Integrated Pest Management are found in 20 medium sized green bolls sampled per New Delhi crops. Maintenance of host free period during off-season acre. Pyrethroids can be used against pink bollworm Common Name : Pink bollworm is a must to ensure a pink boll worm free next season. during this period. The open bolls on the plants should be Local Name : Gulabi/Shendri bond ali Therefore, effective measures of prevention of pink harvested before the spray, as there is likelihood of aphid Scientific Name : Pectinophora gossypiella Saund. bollworm damage include post harvest, off-season and resurgence. When there is resurgence of aphids that Family : Gelechiidae preplanting actions. Allowing cattle grazing of the left Order : Lepidoptera would affect the quality of cotton it is recommended to Pest Category : Borer over green bolls on the plant at the end of crop season, spray any one organophosphorus insecticides. This takes timely crop termination to maintain closed season, clean care of pinkies as well as stainers resulting in the harvest up/ destruction of cotton stubbles immediate to harvest, of quality cotton. avoiding stacking of cotton stalks for fuel purpose over Recommended insecticides for pink bollworm management Published by long periods and summer deep ploughing to expose the Dr. B. M. Khadi pupae of the surviving larvae constitute post harvest and Director off season cultural measures. These practices adopted on Central Institute for Cotton Research Post Bag No. 2, Shankar Nagar P. O. a field-to-field basis over large areas of cotton growing Nagpur 440 010 regions by the cultivators would largely bring down the Maharashtra attack of pink bollworm in the ensuing season. While planning for the next season selection of varieties with early maturity, drying of seeds under sun for 6-8 hours and sowing of acid delinted seeds are effective and economical to prevent the carry over of pink bollworm to the next cotton season. During the cropping season care must be taken to monitor Acknowledgement Mrs. M. Chakrabarty pink bollworm infestation on the crop. This can be done Scientist I/c, TMC-MM I Cell Produced under easily through the use of gossyplure pheromone baited Central Institute for Cotton Research Technology Mission on Cotton traps that attract the males. Once few male moths are Nagpur Mini Mission I (3.1) found in the traps it is an indication of the incidence starting in the bolls of the cotton plants. One approach of Project on pink bollworm suppression is to trap most of the male “IPM Implementation at Village Level for Production moths in the crop ecosystem by using large number of Printing of Good Quality Cotton” pheromone traps (@ 20 nos./ha) so that mating is Mudrashilpa Offset Printers The amount of spray fluid varies more with the canopy Nagpur. Ph. 2231716 disrupted and the population development is arrested. For size than with the crop age. It is recommended that power Funded by this method to be effective traps should be placed over sprayers be used against bollworm management through Ministry of Agriculture many fields over larger areas. Since the damage and insecticides. Normally 200-300 litres/ha of water should Government of India March 2007 stages of pink bollworm are not visible the decision of be used for a crop that had attained eight to sixteen nodes. Description of Insect Stages: attacked from under hotter regions. The mature larvae are either 'short-cycle' Egg: Eggs are pearly iridescent white, flattened, oval bracteoles. Larvae feed and will go on to pupate or 'long cycle' to enter a state of measuring approximately 0.5 mm long, 0.25 mm wide on the developing seeds. diapause. While the former is the observed phenomenon and sculptured with longitudinal lines. Eggs are laid While in younger bolls in South India, diapause is seen in the North and Central singly or in groups of four to five. entire content may be parts of India. Short cycle larvae pupating may cut a Larva: First two instars destroyed, in older bolls round exit hole through carpel wall and fall to ground or are white, while from development could be may tunnel the cuticle, leaving it as a transparent window third instar pink colour completed on three to Larva feeding on seeds and pupate inside. Pupation is inside a loose fitting develops. The larvae four seeds. Interloculi cocoon with a highly webbed exit at one end. Pupal period have the characteristic movement is also seen. ranges between 8 and 13 days. The life cycle is completed dark brown head due to Several larvae can infest in 3-6 weeks. Late season has invariably overlapping t h e s c l e r o t i s e d a single boll. broods. The long cycle larvae entering diapause, spins a incidence and infestation levels vary. The effective prothoracic shield. Symptoms: tough thick walled, closely woven, spherical cell referred population buildup starts after 100 to 110 days of crop Early instar larva Pupa: Pupae are light ' R o s e t t e d f l o w e r ' as “ hibernaculum” with no exit hole. Always, the long- emergence, while the peak infestations occur after 140 brown when fresh, (improper opening of term larvae occur during end of crop season, where there days. The crop with late maturity suffers heavy attack gradually become dark petals) is typical of are mature bolls present and larvae often form their with 50-75 % of the bolls showing damaged locule (s) in Exit hole by larva before pupation brown as the pupation bollworm attack. Small hibernaculae inside seeds. Hibernacula may occupy proceeds. Pupa measures exit holes (smaller than single seeds or double seeds. P. gossypiella hibernate as up to 7 mm in length. the feeding holes of other full fed larvae during cold weather. Diapause larvae often Adult: The adult moth is two bollworms viz., spin up in the lint of an open boll and if still active in greyish brown with Earias & Helicoverpa) ginnery, will spin up on bales of lint, bags of seed or in blackish bands on the Late instar larva are seen on developing cracks and crevices. Moths emerging from the forewings and the hind green bolls. Stained lint hibernating larvae are long lived with females and males wings are silvery grey. around feeding areas alive for 56 and 20 days, respectively. Moths emerge from resulting in bad quality Improper opening of boll Seasonal Dynamics: pupae in the morning or kapas is seen in open Insect is highly adaptable to different climatic conditions in the evening, but are bolls. Improper boll and larvae hide over unfavourable season inside empty n o c t u r n a l , h i d i n g opening with damaged amongst soil debris or seeds are obvious. Small cracks during the day. round holes are seen on Nature of Damage: Adult of Pectinophora the septa between locules Larva when attacks the of open bolls. Lint of pink bud of less than 10 days bollworm attacked bolls Pectinophora damage in open bolls old, shedding of bud is of inferior quality. occurs and larva dies. But Life History: with older bud, larva can Early in the season, eggs are laid in any of the sheltered complete development. places of the plant axis of petioles or peduncles, the There can be cent percent underside of young leaves, on buds or flowers. Once the p i n k b o l l w o r m bolls are 15 days old, Rosetted bloom cottonseed in which they are well protected and remain infestation on bolls but these become favored open bolls. In the last five years, the levels of incidence alive for many months. Survival of the pest from one there need not be any sites for oviposition. were high during 2002 & 2003, whereas 2005 had the season to another is entirely through hibernating larvae in shedding. Larva in flower Incubation period is 3-6 lowest incidence as well as damage. The higher damage seeds, soils and plant debris. Incidence of P. gossypiella bud spins webbing that days. First two instars are levels despite lower incidence arise due to less number of prevents proper flower white, while from third during the season commences from the moth emerging bolls available at the end of season. If the pink bollworm opening leading to i n s t a r p i n k c o l o u r from the over wintering larvae through the summer appears early in the crop season due to favourable “rosetted-bloom”.