Farming’s chemicals mix killing more bees – studyon August 4, 2021 at 11:06 pm

- Advertisement -
- Advertisement -
- Advertisement -
- Advertisement -

Commercial formulas, which contain multiple chemicals, should require their own licences, researchers say.

European honey bees

image sourceGetty Images

Agricultural pesticides sold to farmers ready-mixed into “cocktails” can kill twice as many bees, according to an analysis of 90 studies.

Each measured the impact of environmental stresses such as pesticides and poor nutrition.

And they say commercial formulas, which contain multiple chemicals, should now require their own licences.

Meadow

image sourceVictoria Gill

“Exposure to multiple pesticides is the norm, not the exception,” Dr Harry Siviter, from the University of Texas at Austin, who led the study, told the BBC Radio 4’s Inside Science programme.

One 2016 study showed bee colonies containing larger numbers of pesticides were much more likely to die.

“If you have a honeybee colony exposed to one pesticide that kills 10% of the bees and another pesticide that kills another 10%, you would expect, if those effects were additive, for 20% of the bees to be killed,” Dr Siviter said.

But a “synergistic effect” could produce 30-40% mortality.

“And that’s exactly what we found when we looked at the interactions,” he said.

“So we really should consider the interaction between those chemicals” when licensing commercial formulas for use, Dr Siviter said.

“We don’t continue to monitor pesticides once they’re licensed for use, so we’re proposing post-licensing observations.

“If those pesticides [used in combination] harm bees, that harm is recorded.”

Another study published this week, however, suggests bees around the world are developing the ability to “clear out” a particularly damaging parasite – varroa, a mite that lives and feeds on honeybees and larvae.

Varroa mites (red spot) on a honeybee

image sourceUniversity of Hawaii

Bees already have complex organised hygienic behaviours, such as removing infected broods of larvae from the hive.

And now, data published in the Royal Society journal Proceedings B, from 40 years of research into colonies that survive infestations, without any chemical treatment, reveals they are evolving to “repurpose” that behaviour against varroa.

“We’re seeing this resistance increasing around the world,” Isobel Grindrod, from the University of Salford, said.

“And we’re also seeing an increase recently in bee-keepers not having to treat [the mites] with chemical treatments.”

“Pressure” from the mites was driving healthy bees to adapt, she said.

“Their adaptability is really important, and that’s why we need to maintain healthy bee colonies – to keep that adaptability – because there will be other, new diseases and pressures in the future.”

Hear more about bees’ battles with parasites and pesticides on BBC Inside Science on Radio 4 and BBC Sounds

Follow Victoria on Twitter.

- Advertisement -

Discover

Sponsor

Latest

VA Delays Rollout of Electronic Medical Records System Again, Citing Pandemic

The COVID-19 pandemic is taking its toll on an unlikely mark: the Department of Veterans Affairs' new electronic health record system. VA officials told congressional leaders...

Florida building collapse: Fifth body found in survivor hunton June 27, 2021 at 4:13 am

It comes after a 2018 report highlighting a "major error" in the building's design was made public.The death toll has risen to five after...

Local elections: Tories warn of post-Corbyn Labour ‘bounce’on March 27, 2021 at 1:13 am

The party promises to "build back better" from the pandemic as it launches its English elections push.image copyrightconsarvative partyThe Conservative Party will launch its...

American, Delta and others apply for relief grants — now comes the hard part

KEY POINTS U.S. airline executives face a test to see which sacrifices they are willing to make in exchange for federal aid that would...

Senior MP demands answers for leaseholderson May 30, 2021 at 3:43 am

Clive Betts asks why guidance for leaseholders selling or remortgaging flats is not being followed.Clive Betts asks why guidance for leaseholders selling or remortgaging...