Indian journal of Experimental Biology Vol. 37, April 1999, pp. 374-378 Effect of four benzophenylureas on population of safflower aphid, Dactynotus carthami HRL.and lady bird predators, Coccinella septumpunctata L.and Coccinella sp. S Chakraborty * & M L Chatterjee Department of Agricultural Entomology Bidhan Chandra Krishi Vi swavidyalaya P. O. Krishi Viswavidyalaya, Mohanpur 741252, India Re ce ived /2 May /998; revised 29 November /998 A detailed fi e ld study was conducted to asses the bi oefficacy of 4 benzophenylureas viz, triflumuron, ditlubenzuron, te- flubenzuron and flufenoxuron, agaist the safflower aphid, D. carthami and their safeness to the lady bird predator s, C. sep- tumpunctata and Cocc in ella spp .. The chemicals were applied @ 25 , 50, 75 and 100 g a.i. /ha and all of them exhibited good bioflicacy. Amongst them triflumuron was the most effective one. against the aphid. The toxicity of these urea derivati ves was dose-dependent. They inhibited the process of chitin biosynthesis and caused moulting fai lure, deformity and mosaic formation in the wide populations. In veiw of increasing regulatory and social demands for safer, biodegradable, specific, environmental friendly and economical insecticides, the focus of insect control has shifted towards biorational approaches of pest managment involing insecticides which adversely affect or modify the biochemical and physiological processes of the target organism. The discovery of the 'paper factor" and subsequent development of novel group of insecticides 2 called' insect growth regulators I is a biorational approch for alternate pest managment. Apart from direct killing, the chemicals regulate insect's growth and development and found relatively selective and comparatively safer to the natural enemies'-I o. In order to have a better understanding of the effects of the chemicals at field level, a detailed study has been made with 4 benzophenylureas on the safflower aphid, Dactynotus carthami HRL.(Aphididae: Hemiptera) and the lady bird predators, Coccinella septumpunctata L. and Coccinella sp. (Coccinellidae : Coleoptera). Materials and methods The test chemicals were 4 formulated benzophenylurea compounds, namely triflllmuron { I (4-trifluoromethoxyphenyl)-3-(2-Chlorobenzoyl)- urea} (25 WP), diflubenzuron {1-(4-chlorophenyl)-3- (2, 6-difluorbenzoyl) urea} (25 WP), teflubenzuron • Present address: Regional Research Station, BCKV P.O.-Patiram 733133, West Bengal {1-(3, 5-dichloro-2, 4-difluorophenyl)-3-(2, 6-difluo- robenzoyl) urea} (15 SC) and flufenoxuron { 1-4 (2- chloro-4-(trifluoromethylphenoxy) 2-fluoropheny l- 3- (2, 6-difluoro-benzoyl) urea} (10 EC). The chemicals were applied @ 25, 50, 75 and 100 g active ingradientlha (ga i/ ha) . Test insect The test insects were the safflower aphi d, Dactynotus carthemi and lady bird redator s, Cocci nella septumpunctata and Coccinella sp .. Adults, grubs and nymphs we re counted altogether while taking the field data. Test procedure The experiments were conducted for two consecutive seasons. They were laid out in randomized block design with three replications for each treatment along with an untreated check. Each plot measured 4mx4m. A high yielding sufflower cultivar was used for raising the crop following recommended packages of practices and left fo r natural infestation for some time. Three sprays were given at an interval of 15 days in cluding water spray as control with the help of a 51 capacity brass sprayer @ 400 I I ha. The count of the live insect was taken from 5x3 randomly selected tagged plants per treatment excluding the border plants and the average