Metal pollutants and their impact on honey bees (Apis mellifera L.): Examining behavior, survival, and ecology

Rapid industrialization and urbanization worldwide has continued to release more and more anthropogenic contaminants into the environment.  Pollutants such as selenium, cadmium, copper, and lead have appeared in honey bee (Apis mellifera L.) hives throughout the world, yet there is very little research on their toxic effects.  Our work focuses on the toxicity of various pollutants to behavior, survival, and ecology of the common pollinator, the honey bee.  We conducted laboratory bioassays involving proboscis extension reflex (PER) and survival.  Foragers dosed with certain pollutants exhibited reduced learning, and larvae experienced high mortality even at low doses.  In a cage study examining the honey bee colony as a whole, caste differences in selenium distribution reduced brood exposure, but even modest transfers of selenium can cause developmental defects.  In greenhouse and semi-field studies, certain plant species accumulated pollutants in their flowers, yet still remained attractive to foraging honey bees.  Knowing which pollutants pose the most risk to pollinators is crucial information for farmers and beekeepers alike.  Minimizing exposure to environmental stressors is essential for maintaining healthy honey bee colonies for optimal pollinating services.