Stressed bees are pessimistic pollinators

The bees are having a rough go of it. Declining populations, parasitic wasps, and continued environmental degradation would be stressful situations for any species--and the planet's vital pollinators appear to respond to pressure much like many humans do. New research published on October 9 in the Proceedings of the Royal Society B from a team at Newcastle University suggests that just like us, bees are more likely to make pessimistic choices after being put through the ringer. To test what happens when bees are under duress, the team first trained three groups of the female worker bumblebees to identify and associate different colors with varying outcomes--a blue LED screen represented a location with a sweeter reward, while green indicated a less favorable water solution. Once the bees understood each color's reward amount, researchers then placed the groups in chambers with varying hues that fell in the spectrum between blue and green, then simulated a predatory attack for two groups, either by giving them a light shake or temporarily trapping them with a sponge-tipped robotic arm.