Recent studies of honeybees and bumblebees have examined combinatory effects of different stressors, as insect pollinators are naturally exposed to multiple stressors. At the same time, the potential influences of simultaneously occurring agricultural agents on insect pollinator health remain largely unknown.
Due to different farming methods, and the drift of applied agents and manure, pollinators are most probably exposed to insecticides but also bacteria from organic fertilizers at the same time.
We orally exposed honeybee workers to sub-lethal doses of the insecticide thiacloprid and two strains of the bacterium Enterococcus faecalis, which can occur in manure from farming animals.
Our results show that under laboratory conditions the bees simultaneously exposed to the bacterium and the pesticide thiacloprid had significantly higher survival rates 11 days post-exposure than the controls, which surprisingly showed the lowest survival.
[C]aloric restriction through behavioural and physiological adaptations may have mediated an improved survival and stress resistance in our tests. However, the decreased food consumption could in long-term also result in possible negative effects at colony level.