Entomology

Entomology section conducted research on different aspects to protect the crop from insect pests of cotton. It was observed that thrips, jassid and whitefly damaged the crop in early stage when the crop was in vegetative growth during the months of June and July. On the other hand, bollworms showed their damage during August to September. Whereas, pink bollworm damaged the crop in fruiting parts from July to harvesting in both Bt. as well as non Bt. varieties in Sindh. The cotton growers applied different groups of insecticides to control the pink bollworm but did not obtain successful results cultural practices and use of sex pheromone traps gave significant result in suppressing this insect. The lepidopterousinsects were monitored by sex pheromone and light trap throughout the year. Maximum lepidopterouspests were caught in sex pheromone trap as compared to light traps. However less number of pink bollworm male adults was caught in pheromone traps as compared to the last year.   

Host plant resistance studies were carried out on three promising varieties developed by plant breeding section viz. Bt.CRIS-671, Bt.CRIS-673 andBt.CRIS-638 compared with standard Bt.CRIS-508. Maximum population of thrips (29.13/leaf) was recorded in Bt.CRIS-673 whereas jassid (3.58/leaf), in Bt.CRIS-508 whereas maximum population of whitefly (1.63/leaf) was observed in Bt.CRIS-638 and maximum bollworm damage (5.0 %) were recorded in Bt.CRIS-671 under unsprayed condition. It was advised that poisonous chemical should be used carefully when alternate control measures fail to control the pests. Pest scouting service and trainings were also provided to growers regarding cotton production and protection technology to get better cotton yield. Indiscriminate use of insecticides for the control of cotton insect pest should be avoided which developed resistance in insect, also causes leaf burning and fruit shedding etc.