How are bees affected by pesticides? A new study shows that it affects the bees’ behavior, from socializing to wax cap building.

Neonicotinoid Pesticide Exposure

Previous studies have shown that exposure to neonicotinoid pesticides can actually affect bees’ foraging behavior. It is a problematic issue given the bees’ growing struggles, but a new study shows that foraging behavior may just be the beginning of bees’ pesticide problems.

In a new study, researchers observed bees’ behavior when exposed to neonicotinoids and found that those exposed were actually less social than those who were not exposed and spent less time nursing the larvae. Furthermore, additional testing revealed that the pesticide-exposed bees actually had impaired abilities to warm the nest and to build wax caps.

Bee Behavior Affected

To conduct their study, researchers placed black and white tags with simplified bar codes on each bee, and a camera over the colonies was able to automatically track each bee. Here, the researchers were able to observe how the bees exposed to pesticide spent less time interacting with others and even spent more time at the outer boundary of the colony.

Interestingly, researchers did not notice much effect during the day but strongly observed the results at night. As such, researchers surmise that it could be possible that the pesticides are affecting the bees’ circadian rhythm.

In additional experiments, researchers placed temperature probes in outdoor hives. This is because normally, bees are able to immediately detect temperature drops or spikes and move their muscles to bring the hive back to optimal temperatures. The behavior was observed in all the control samples even in widely fluctuating temperatures, but the pesticide-exposed bees appeared to dramatically lose their temperature-regulating ability.

Furthermore, the bees also lost the ability to build insulating wax caps over the colony.

Tighter Pesticide Regulations

As such, the researchers surmise that perhaps it's time to for tighter pesticide regulations.

“I think we're at a point where we should be very, very concerned about how the ways in which we're changing the environment is undercutting and decimating insect populations that are important not only for the function of every ecosystem...but that are very important for food production,” said study lead James Crall.

The study is published in Science.

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