Farmers' participatory field trials were conducted with transgenic (Bacillus thuringiensis) and conventional cotton (Gossypium hirsurum L.) hybrids in integrated pest management and non-integrated pest management modes using different combinations of refugia for two cropping seasons (2003-05) in Nanded district of Maharashtra in central India and one cropping season (2004-05) in Dharwad district of Karnataka of southern India. At Nanded, the experiments were conducted with Br 'MECH 184' and local popular conventional hybrid 'Bunny' and at Dharwad with 'RCH 2' Br and 'RCH 2' conventional popular cotton hybrid. Results on sucking pests indicated no consistent trend with regard to locations and cropping seasons in Br and conventional cottons. The mean incidence of American boliworm (Helicoverpa armigera Hubner), pink bollworm (Pectinophora gossypiella Saunders) and spotted bollworm (Earias insulana Boisd.) larval population and percentage of damaged squares, boils and shed fruiting bodies at both the locations remained significantly high in conventional cotton treatments compared with all the Br cotton treatments. The population of ladybird beetle and Chrysoperla zastrowi arabica Henry et al. was not adversely affected in all Br treatments compared with the conventional cotton treatments. The yield data indicated higher seed cotton yield in all the Br treatments compared to conventional cotton at both the locations. Integrated pest management was necessary for getting the best out of Br cotton and 20% refugia reduced the seed cotton yield without giving substantial benefit in terms of bollworm control or conserving higher natural enemy population.

Cotton crop is ravaged by more than 162 species of insect pests, causing 50-60% losses. Four different IPM modules viz., bio-intensive, bio-control + insecticides, bio-control + intercrop were evaluated in comparison with the recommended plant protection schedule to manage the pests and diseases in an ecofriendly manner. Among the modules tested, the bio-control + insecticide module proved to be the best in the management of pests and diseases of cotton and gave higher net returns and C/B ratio. The number of sprays were reduced to three in bio-control + insecticide module as compared to six in the recommended plant protection schedule (farmers practice). The use of bio-agents and bio-pesticides in alteration with chemical insecticides provided enhanced activity of the natural enemies apart from reduced quantum of pesticide applied on the crop. The efficacy of different modules proved significant effectiveness of bio-intensive module and paved the way for implementation and evaluation at village level.

Farmers' participatory field trail was conducted in 33.18 ha representing rainfed cotton-growing region in Nanded district of the central zone, to evaluate the performance of Bt cotton hybrid MECH-162 under Integrated Pest Management (IPM), and to compare it with conventional cotton (CC) hybrids/varieties grown with and without IPM. There was significant reduction in bollworm incidence, particularly the American bollworm (Heliocoverpa armigera) and pink bollworm (Pectinophora gossypiella) and the damage caused by them to the fruiting bodies in Bt MECH-162 compared to CC with IPM. In Bt MECH-162, 11.5% of the fruiting bodies were damaged compared to 29.4% in CC with IPM. Maximum damage was observed in CC without IPM, where seven sprays of pesticides were made for control of insect pests in comparison to three on Bt MECH-162. Population of the sucking pests and two natural enemies monitored was also lower in Bt MECH-162 compared to CC. The latter without IPM recorded the lowest population of natural enemies. Seed cotton yield (12.4 q/ha), and net returns (Rs 16231/ha) were highest for Bt MECH-162. CC under IPM recorded an yield of 7.1 q/ha, and return of Rs 10507/ha. The results show that IPM in cotton was most effective with Bt MECH-162, and provided higher return though the initial seed cost for the farmers was higher.

Field trials were conducted at various locations in India to assess sex pheromone response of Helicoverpa armigera males to varying blends of its two sex pheromone components. In the pheromone septa that were used to bait the pheromone traps varying blends were impregnated and the ratio of Z-9 : hexadecenal to Z-11 : hexadecenal in them varied from 0 : 100 to 15 : 85. Results indicated geographical variation in response of males to varying blends of the two sex pheromone components, suggesting male sex pheromone response polymorphism.