Temporal variation of fatty acid composition and pesticides in honeybees Apis mellifera and beebread

A twelve-month study was conducted on changes in fatty acid composition and pesticide residues in honeybees and beebread. In honeybees, saturated fatty acid and monounsaturated fatty acid gradually increased as summer began then decreased when spring started, and polyunsaturated fatty acid had an opposite seasonal trend. Similar fluctuation was observed in the beebread collected from the same hive as those honeybees through summer to fall, especially in the essential fatty acids omega-6 and omega-3. Honeybees lipid metabolism can be disrupted after being exposed to a sub-lethal level of pesticide. Although three out of sixteen analyzed pesticides were detected in beebread samples summer through fall in our study, we were not able to find any negative affect of those pesticides on the honeybees fatty acid composition. Temporary field-realistic pesticide exposure may weaken honeybees but are unlikely to show any reflection in their fat bodies if the colony was otherwise healthy.