Toxic nectar affects the behavior of insect pollinators

Natural toxins in nectar and pollen can poison insects and affect their memory, behavior and reproductive success, researchers have found. Toxins in lupin pollen cause bumble bees to produce fewer offspring while chemicals found in rhododendron nectar are toxic to honeybees but not bumble bees, toxic effects that could be contributing to the worrying decline in pollinator species.

http://sciencedaily.com/releases/2014/12/141211210006.htm