Bees exposed to one dose of pesticide could take generations to recover

The knock-on environmental effect of dwindling bee populations could be severe

Samuel Webb
Tuesday 23 November 2021 14:06
Comments
The Humble Honey Bee

Bees exposed to a single dose of pesticide may require generations to recover, new research has revealed.

Pesticide is known to cause population decline in bees but the extent it has over time is still not fully understood.

Clara Stuligross and Neal M. Williams of the University of California say the chemicals may produce carryover effects that influence reproduction and population dynamics over time.

The researchers state: “Global insect declines are profoundly concerning, especially for groups like bees that provide important services to humanity.

Pesticide exposure, both directly to foraging bees and via carryover effects from past exposure, dramatically reduced bee reproduction, which reduced population growth.

“Carryover effects reduced bee reproduction by 20% beyond current impacts on foraging bees, exacerbating the negative impact on population growth rates.”

This indicates that bees may require multiple generations to recover from a single pesticide exposure.

Pesticides are linked to global insect declines, with impacts on biodiversity and essential ecosystems.

The researchers found that the combined threats reduced blue orchard bee reproduction by 57 per cent and resulted in fewer female offspring.

“Just like humans, bees don’t face one single stress or threat,” said lead author Clara Stuligross, a Ph.D. candidate in ecology at UC Davis.

“Understanding how multiple stressors interplay is really important, especially for bee populations in agricultural systems, where wild bees are commonly exposed to pesticides and food can be scarce.”

The study found that pesticide exposure had the greatest impact on nesting activity and the number of offspring the bees produced. Pesticide exposure reduced bee reproduction 1.75 times more than limiting their food.

The team conducted their research by exposing the blue orchard bee to the neonicotinoid insecticide imidacloprid, the most widely used neonicotinoid in the United States. It’s also among the most frequently applied insecticides in California.

The study authors said the research can help farmers make decisions about how they manage the environment around orchards.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Please enter a valid email
Please enter a valid email
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Please enter your first name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
Please enter your last name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
You must be over 18 years old to register
You must be over 18 years old to register
Opt-out-policy
You can opt-out at any time by signing in to your account to manage your preferences. Each email has a link to unsubscribe.

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged in