When a Cornell-led team of scientists analyzed two dozen environmental factors to understand bumblebee population declines and range contractions, they expected to find stressors like changes in land use, geography or insecticides.
Instead, they found a shocker: fungicides, commonly thought to have no impact.
“Insecticides work; they kill insects. Fungicides have been largely overlooked because they are not targeted for insects, but fungicides may not be quite as benign – toward bumblebees – as we once thought. This surprised us,” said Scott McArt, assistant professor of entomology and the lead author on a new study published Nov. 15 in the journal Proceedings of the Royal Society B.
While science has studied insecticides, such as neonicotinoids, that attack bugs’ central nervous systems, this new work shows how fungicides – particularly chlorothalonil, a general-use fungicide often found in bumblebee and honeybee hives – may negatively affect bee health, said McArt, a fellow at Cornell’s Atkinson Center for a Sustainable Future.
Building on a large data set collected by Sydney Cameron, professor of entomology at the University of Illinois, the scientists discovered what they call “landscape-scale” connections between fungicide usage, pathogen prevalence and declines of endangered United States bumblebees. (Landscape scale refers to the area in which foraging bumblebees live, about 2 kilometers in diameter.)
While fungicides control plant pathogens in crops, the bees pick up their residue when foraging for pollen and nectar. As farms use both insecticides and fungicides, the scientists worry about synergy. “While most fungicides are relatively nontoxic to bees, many are known to interact synergistically with insecticides, greatly increasing their toxicity to the bees,” McArt said.
Chlorothalonil has been linked to stunted colony growth in bumblebees and an increased vulnerability to Nosema, a fatal gut infection in bumblebees and honeybees.
“Nosema can be devastating to bumblebees and honeybees,” said McArt. “Since fungicide exposure can increase susceptibility of bees to Nosema, this may be the reason we’re seeing links between fungicide exposure, Nosema prevalence and bumblebee declines across the United States in this data set.”
For domestic and global agriculture, bumblebees are a key component due to their ability to use “buzz pollination” that vibrates and shakes pollen loose from flowers. In the United States, bees contribute more than $15 billion to the economy and $170 billion to global agribusiness, according to global economic research and a 2012 Cornell study. While half of crop pollination work is done by commercially managed honeybees in the U.S., the other half is done by bumblebees and wild bees. In New York, pollination services contribute $500 million to the state’s agricultural economy.
McArt and his Cornell colleagues will continue to investigate fungicide-insecticide synergisms and fungicide-pathogen interactions under the New York State Pollinator Protection Plan and a new grant from the New York Farm Viability Institute.
The Latest on: Bee decline
- The 10 Prettiest Plants That’ll Bring All the Butterflies, Hummingbirds and Bees to Your Yardon March 22, 2020 at 7:26 am
The expression “busy as a bee” certainly applies when it comes to our tiny garden visitors that carry minuscule pollen grains from flower to flower. Those industrious insects—along with other ...
- Bee Counter Will Have You Up To Your Nectar In Hive Dataon March 22, 2020 at 1:04 am
With the world’s bee population in decline, it’s more important than ever to monitor the health of hives. One way to do that is to count the bees as they leave and reenter the hive. You can use the ...
- 'Drag Race' Recap: Season 12 Episode 4 — [Spoiler] Eliminatedon March 20, 2020 at 6:50 pm
And Friday’s episode tested the queens’ handling of balls like never before. But first, the mini challenge: Ru’s dirty dozen was tasked with raising awareness about the world’s declining bee ...
- The four simple ways you too can ‘bee’ a pollinator gardeneron March 20, 2020 at 1:50 am
Consider becoming part of the solution to the declining populations of bees by taking some of these relatively easy steps — you will be glad you did. Steve Smith is the owner of Sunnyside Nursery in ...
- AP Source: Raiders decline option to stay in Oakland in 2020on March 18, 2020 at 5:02 pm
A person familiar with the team’s plans says the Raiders have declined an option to remain in Oakland for 2020 and are on target to move into their new Las Vegas stadium this summer.
- Drag Race Sneak Peek: Season 12's 'Queen Bee' Is Revealed — Watchon March 18, 2020 at 11:24 am
The queens of RuPaul's Drag Race Season 12 are getting into formation. As revealed in this 11-minute clip from Friday's episode (VH1, 8/7c), the remaining contestants transform themselves into winged, ...
- Aduro: Float Like A Butterfly, Sting Like A Beeon March 18, 2020 at 10:03 am
Numerous catalysts should drive momentum in 2020. Aduro is collaborating with leading pharmaceutical companies like Merck, Eli Lilly, and Novartis. Corporate re ...
- Bee-saving practices sometimes are more marketing than real helpon March 14, 2020 at 5:04 am
Such products as bee hotels are advertised as safe nests, but some may be dangerous. Other promotions distort environmental priorities.
- Bee lawns generate national buzzon March 13, 2020 at 10:24 am
The stakes are high: More than 1 in 3 bites of food taken in the United States depends on bees and other pollinators. But bee populations have been declining at unusually high rates in recent years.
- How Yorkshire volunteers are fighting back against decline in butterfly numberson March 11, 2020 at 9:53 am
Nick Hall from Butterfly Conservation Yorkshire and Ros Forbes-Adams, pictured next to a bee house in the wood meadow at Three Hagges Wood near Escrick ... Published every five years or so, it cited ...
via Google News and Bing News