
Bombus impatiens nectaring on Lantana sp. in Okemos, Michigan. Photo taken September 24, 2017 by F. W. Ravlin. Canon 5D Mark III, 100 mm macro.
Pyrethroid pesticides are effective. Sometimes too effective.
Researchers at Michigan State University’s entomology department have unlocked a key to maintain the insecticide’s effectiveness in eliminating pests without killing beneficial bugs, such as bees. The study, featured in the current issue of Proceedings of the National Academy of Sciences, shows that molecular tweaks can make the difference.
Pyrethroids target the voltage-gated sodium channel, a protein found in nerve and muscle cells used for rapid electrical signaling. Pyrethroids basically work by binding to the voltage gate of the sodium channel and prevent it from closing. The nervous system becomes over-stimulated and the insect is killed. These pesticides, however, don’t have the same effect on humans, or other mammals for that matter.
Ke Dong, MSU insect toxicologist and neurobiologist and co-author of the paper, honed in on a single protein that could afford bumble bees the same resistance as humans – tau-fluvalinate, a pyrethroid insecticide. Dong worked with Shaoying Wu, lead author from Henan Agricultural University (China), who conducted the research in Dong’s lab as a visiting scholar.
“For the first time we are showing that unique structural features in bee sodium channels interfere with the binding of tau-fluvalinate to bumble bee sodium channels,” Dong said. “This opens the possibility of designing new chemicals that target sodium channels of pests but spare bees.”
Sodium channels are large transmembrane proteins of more than 2,000 amino acid residues. Dong’s lab spent many years unraveling this groundbreaking advance. The scientists initially started with sodium channels from other bugs, such as mosquitoes, fruit flies, cockroaches, mites and ticks, to find where pyrethroids bind on insect sodium channels to effectively kill them. They got some help from nature.
“By examining wild mosquitoes that have become resistant to pyrethroids, we were able to help narrow down the potential sites on which to focus,” Dong said.
Specifically, in a previous study, Dong and the team identified mutations that made the channels more resistant to pyrethroids. Working with Boris Zhorov, a computer modeling expert from McMaster University in Canada, they identified two distinct pyrethroid binding sites on insect sodium channels. They also uncovered the molecular differences between mammals’ and insects’ differing reactions to pyrethroids.
For the current study, the team focused on a longstanding enigma that bumble bees and honey bees are highly sensitive to most pyrethroids, but they were resistant to tau-fluvalinate. Currently, tau-fluvalinate is widely used to control agricultural pests and also varroa mites, which are one of the biggest threats to bees worldwide.
Eventually, the team discovered that the channel is resistant to tau-fluvalinate but sensitive to other pyrethroids. Further mutational analysis and computer modeling revealed that specific amino acid residues in bumble bee sodium channels are responsible for the selective toxicity.
Future research will examine sodium channels from various pest and beneficial insects to explore the features of pyrethroid binding sites, which could lay the groundwork for designing new and selective pesticides. It also will shed light on how pests develop resistance to insecticides over time and how beneficial insects respond to them in the field.
Learn more: REFINING PESTICIDES TO KILL PESTS, NOT BEES
Check this out if you are interested in beekeeping: Flowers Across Sydney
The Latest on: Pesticides
[google_news title=”” keyword=”pesticides” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Pesticides
- Study identifies pesticides that could influence Parkinson’s diseaseon June 3, 2023 at 3:00 am
The researchers investigated 288 pesticides using agricultural records and discovered that long-term exposure to 53 of these pesticides was associated with Parkinson's disease ...
- Use of irresponsive pesticides causing health hazards: Dr Jalalon June 2, 2023 at 2:20 pm
The irresponsive use of pesticides for the crops and fruits is not only causing health hazards but also resulting in rejection of the agricultural produces in the international markets. This was ...
- Europe has lost over a half-billion birds in 40 years. The single biggest cause? Pesticides and fertilizerson June 2, 2023 at 9:11 am
A trickle of studies warning that the enormous variety of living things on Earth is diminishing has turned into a flood. The evidence for these losses within regions and globally is undeniable. But ...
- Environmental groups sue French state over use of pesticideson June 2, 2023 at 2:51 am
A coalition of French environmental organisations on Thursday accused the French state of negligence in regulating the use of pesticides. A final ruling will be handed down by the Paris ...
- Scientists Identify 97 Pesticides and Flame Retardants in Study of Primate Populationon June 1, 2023 at 9:01 pm
In Uganda’s Kibale National Park, researchers studied the chemical exposure of four species of primates (chimpanzees, Ugandan red colobus, olive baboons and red-tailed monkeys), adding to previous ...
- EPA finds no PFAS in 10 pesticideson June 1, 2023 at 2:48 pm
Yes! I want to get the latest chemistry news from C&EN in my inbox every week. ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly ...
- Europe has lost over half a billion birds in 40 years. The single biggest cause? Pesticides and fertiliserson June 1, 2023 at 8:25 am
This data paints a grim picture: an estimated 550 million birds have been lost from Europe’s total population over the last 40 years or so. It is a shocking statistic, and tells us something profound ...
- The 2023 ‘Dirty Dozen’ pesticides in produce list is outon May 31, 2023 at 2:25 am
The Environmental Working Group has released its annual "Dirty Dozen" list, which names the top 12 produce items with the most pesticides.
- Residential Areas and Early Postnatal Complications among Pregnant Women Linked to Banned and Current Pesticideson May 30, 2023 at 9:01 pm
A study published in Chemosphere supports accumulating scientific research confirming that prohibited and current use pesticides are readily detectable in the human placenta. All pregnant women ...
- The 'Dirty Dozen': These fruits, veggies contain the most pesticideson May 30, 2023 at 3:01 pm
This list details which fruits and vegetables contain the most pesticides. Can you guess what came out on top?
via Bing News