PREDATOR-PREY SCENARIO IN DIFFERENT CULTIVARS OF COTTON

Five cotton cultivars, such as CIM-496, CIM-534, NIAB-111, MNH-786 and Bt-121 were compared in the experiment for resistance against insect pests and presence of predators among them at Agriculture Experimental Farms of University College of Agriculture, Bahauddin Zakariya University, Multan, Pakistan. It was found that there was a significant variation in resistance in these cultivars of cotton against different insect pests but the population of the predators found to be non-significantly different among these cultivars of cotton. Application of synthetic insecticides significantly reduces the predators and pests/prey population as compared to the un- sprayed field. Bt-121 and MNH-786 were the most tolerant cultivars against both the sucking and chewing insect pests of cotton but the application of insecticides would still be required to keep the population of insect pests below the economic damage. It is therefore, recommended that only such cultivars of cotton i.e. Bt-121 and MNH-786, should be sown which are resistant to pest attack because in this way number of insecticide applications in the cropping season could be reduced. Similarly, only those insecticides should be used, which possess minimum toxicity to non-target organisms. Uses of environmental friendly insecticides are accordingly required to be encouraged in Pakistan to avoid deleterious effects of poisons on beneficial insects.