LABORATORY EVALUATION ON INSECTICIDAL TOXICITY TO INDIAN HONEY BEE, APISCERANA INDICA F. (HYMENOPTERA: APIDAE)M. Gokulakrishnan, C. Gailce Leo Justin, S. Sheeba Joyce Roseleen and J. Ejilane
The honey bees are crucial for pollination of a wide range of plants, which is vital for the development and maintenance of biodiversity. Honey bees are critical pollinator around the world, yet it is increasingly vulnerable to illnesses, pesticides, and biotic stresses. Agricultural pesticides are a major cause of pollinator decrease around the world. The relative toxicity of seven insecticides to Apiscerana indica was determined under laboratory conditions. In the laboratory experiment, three methods were evaluated to assess the toxicity of insecticides. Topical and oral bioassay methods revealed similar mortality percentage for all insecticides. Honey bee mortality was reported to be substantially higher in topical and oral bioassays than in indirect filter paper disc bioassay tests. Insecticides viz. profenoFos50EC, thiodicarb 75WP, Imidacloprid 17.8SL, fipronil 5SC, emamectin benzoate 5SG caused100 percent mortality in all the evaluation methods. Chlorantraniliprole 18.5SC and acetamiprid 20SP were found to be moderately and less toxic to honey bees respectively. In all the three methods the minimum LC50 value was obtained in emamectin benzoate 5SG followed by imidacloprid 17.8SL, fipronil 5SC, profenophos 50EC, thiodicarb 75WP, chlorantraniliprole 18.5SC and acetamiprid 20SP. The toxicity of these recommended insecticides varied greatly from extremely toxic to moderately toxic, and A. ceranaindica was killed at all recommended insecticide dosages except in acetamiprid and chlorantraniliprole. Hence, these insecticides should be handled with extreme caution because they kill non-target insects like pollinators.