New research suggests exposure to a "widely-used" pesticide causes bumblebees to be born small and grow less than they would naturally.
Pyrethroid pesticide is commonly used to protect flowering crops from insect damage, but it could be taking a toll on insects that help rather than hurt the plants, a Royal Holloway University of London news release reported.
Researchers believe the chemical "reduces the size of individual bees produced by a colony," the news release reported.
A research team tracked bee colony growth progressed over a four-month-long observational period. They weighed bees using micro-scales and monitored the number of queens and male bees each colony produced.
"We already know that larger bumblebees are more effective at foraging. Our result, revealing that this pesticide causes bees to hatch out at a smaller size, is of concern as the size of workers produced in the field is likely to be a key component of colony success, with smaller bees being less efficient at collecting nectar and pollen from flowers," researcher Gemma Baron of Royal Holloway, said.
This study marks the first time researchers have looked at the damaging effects of pyrethroid pesticides over the course of a bumblebee's entire lifespan.
"Bumblebees are essential to our food chain so it's critical we understand how wild bees might be impacted by the chemicals we are putting into the environment. We know we have to protect plants from insect damage but we need to find a balance and ensure we are not harming our bees in the process," Professor Mark Brown said.
The use of these pesticides is expected to increase in the near future in Europe.
"Our work provides a significant step forward in understanding the detrimental impact of pesticides other than neonicotinoids on wild bees. Further studies using colonies placed in the field are essential to understand the full impacts, and conducting such studies needs to be a priority for scientists and governments," Doctor Nigel Raine, said in the news release.
