Metabolomic analysis of honey bee, Apis mellifera L. response to thiacloprid.

The cyano-substituted neonicotinoid insecticide, thiacloprid, is nowadays widely used in agriculture for controlling insect pests. However, it also simultaneously has adverse effects on the health of important pollinators, such as honey bees. Previous studies have reported that sublethal doses of neonicotinoids impaired immunocompetence, learning and memory performance, and homing behaviour in honey bees. In the present study, using LC-MS-based combined with GC-MS-based metabolomic approaches, we profiled the metabolic changes that occur in the head of honey bee after subchronic exposure to 2 mg/L thiacloprid over 3 days. The estimated total dose of thiacloprid fed to each bee was 0.12 µg. The results showed that there were 115 metabolites significantly affected in thiacloprid-treated bees compared to control. The metabolites with high level of abundance enriched to wide range pathways associated with oxidative stress and detoxification suggest that the honey bees have activated their detoxification system to resistant toxicity of thiacloprid. While, the reduction of serotonin suggest thiacloprid may hinder the brain activity implicated in learning and behaviour development. Our study expand the understanding of the molecular basis of the complex interactions between neonicotinoids and honey bees.