FIELD TOXICITY OF SOME INSECTICIDES AGAINST APIS MELLIFERA (LINNAEAUS) HONEYBEES ON MUSTARD
SURENDRA KUMAR SHARMA *
BEE RESEARCH STATION. CSK. HPK VISHVAVIDYALAYA, NAGROTA BAGWAN-176047, INDIA
*Author to whom correspondence should be addressed.
Abstract
Field weathered toxicity of insecticides at recommended Concentrations against 4pix iiwllijru L. honeybees on mustard crop variety varuna for two years were worked out. Relaive efficacy, the PT values in the order of d-mcthyl >dimelhoate >cypermcthrin >endosulfan were observed. Relative persistence in terms of their LT values was recorded as d-methyl (0.63 hrs) followed by cypcrmethrin (2.42 hrs). dimethoatc (2.60 hrs) and endosulfan (11.51 hrs). The LC values of these insecticides on this crop «gainsi A itwll.fr’ra workers under laboratory conditions were recorded as; 70.09. 78.05. 186.76 and 1138.15 ppm for d-methyl. cypermethrin, dimcthoate and endosulfan, respectively. The regression equations for field toxicity of hesc insecticides have also been worked out. Among these insecticides endosulfan was observed to be the saÑr and d.niethyl as the highly toxic against forager honeybees.
Keywords: Apis mellifera, mustard (Brassica juncea), toxicity, demcton-methyl, diineihoate, cypermethrin, endosulfan, PT, forager honeybees, LC, LT