Evaluation of acute contact toxicity of imidacloprid to Apis mellifera under laboratory conditions

Abstract

Neonicotinyl, systemic insecticides are very popular amongst the growers due to their low mammalian toxicity and the ability to move systemically into the entire plants, observed to be highly toxic to bees and are well known causal of colony collapse disorder in beekeeping industry throughout the world. In this communication, evaluation of imidacloprid toxicity to assess the risk posed to honey bees in field young worker bees of A. mellifera were carried out using hand operated micro-applicator under laboratory at 25±2 oC and 65±5 relative humidity in Sloan, Himachal Pradesh during august 2017. The toxicological investigations carried out on ten individuals of young, workers of Apis mellifera per replication were topically treated with imidacloprid dose ranged between 0.005 to 0.12 µg/bee. Mortality of bees was data recorded after 24 hours of treatments and subjected to probit analysis. LD50 value worked out to be 0.037 µg/bee with a fiducial limit of 0.019 and 0.068 µg/bee. It was concluded that mortality data in relation to dose was homogeneous, as the determination of acute contact toxicity of imidacloprid is essential at sublethal levels