Susceptibility Comparison of Bumblebee and Honeybee to Acetamiprid and Imidacloprid

Abstract

midacloprid and acetamiprid are neonicotinoid insecticides introduced in the market for the control of insect pests of agricultural crops, but unfortunately these insecticides are causing harmful effect on non-target organisms including honeybees and bumblebees. Insecticides of this group effect acetylcholine nicotinic receptors. Apis mellifera, the European honeybee and Bombus haemorrhoidalis are important pollinators for wild and managed crops in Pakistan, but unfortunately their population is declining day by day at alarming rate. This study was design to find out the susceptibility level and insecticidal toxicity comparison on A. mellifera and B.  haemorrhoidalis to acetamiprid and imidacloprid under controlled laboratory conditions by using contact and oral exposure methods. The results of oral method by using sugar solution showed that honeybee is more susceptible as compared to bumblebee on both insecticides. Maximum mortality i.e. 20%, 35%, 66%, in honeybee and 16%, 29%, 45% in bumblebee workers at acetamiprid and at imidacloprid 46%, 67%, 83% in honeybee and 34%, 56%, 72% in bumblebee were observed respectively after the exposure of 3hrs. 6hrs. and 24hrs. Similar susceptibly results were found on pollen and contact method. Overall results demonstrate that these both neonicotinoid insecticides are toxic for bumblebees and honeybees, and honeybee workers are more susceptible as compared to bumblebee workers at company recommended field realistic dose.