Conservation survey finds native New York state pollinators at risk
A New York state survey supported by Cornell bee experts shows that more than half of important native pollinators are at risk of extinction, potentially threatening crops, wildflowers and insect diversity.
The three-year Empire State Native Pollinator Survey, released Aug. 4 by the State Department of Environmental Conservation (DEC), found that at least 38% — and as many as 60% — of the pollinators targeted by the survey are at risk. run because they are rare or are declining. For bees, up to 24% of species may be at risk and a further 11% are considered potentially extirpated, or known only from historical records. The study is one of the most systematic assessments of pollinator conservation status conducted by any state, according to the authors.
The research provides a basis for future monitoring of wild bees, wasps, flies, beetles and moths that are the main pollinators of crops, wildflowers and host plants, and provides recommendations aimed at preserving biodiversity – from preserving habitats to reduced use of pesticides.
“There’s some evidence that the abundance of many of these species has really declined, and that’s worrying,” said Bryan Danforth, a professor in the Department of Entomology at the College of Agriculture and Life Sciences. “A lot of New York state agriculture relies on insect-pollinated crops, so that’s a practical reason for concern. And if we lose some of these bees, we’re losing a really interesting bit of insect diversity in New York. would also lose some native wildflowers.”
Danforth’s lab led the survey’s identification of more than 20,000 bee specimens now housed in the Cornell University Insect Collection, one of the largest in North America, with samples dating back to the 1860s. Lab manager Maria Van Dyke led the survey. taxonomic effort, supported by a team of trained students.
Danforth and Van Dyke were part of an advisory committee that helped design the research in 2017 that was administered by the New York Natural Heritage Program, part of the State University of New York’s College of Environmental Science and Forestry, under a contract of the DEC.
The researchers first identified the “focal taxa” they would look for, a representative subset of native pollinators (excluding honeybees, which are not native). They then compared historical data, including from Cornell’s collection, with extensive field surveys conducted in grassland, woodland, wetland and roadside habitats across the state — about 50 sites per year from 2018 to 2020.
Overall, assisted by citizen scientists who uploaded photos to the iNaturalist platform, the study awarded NatureServe conservation status, or “S ranks,” to 457 species.
Using conservative criteria, less than half of the species were ranked as safe, with 23% classified as high-risk and another 15% not seen in New York since 2000. But more typical criteria for determining risk species suggested that 60 % possibly in New York at risk.
“That’s a lot of species that we can’t find in the state in great numbers, that seem to have disappeared from much of their former range, or that we can’t find at all despite quite a significant effort over three years,” said Matthew Schlesinger. , chief zoologist for the New York Natural Heritage Program and author of the research report. “When we lose species, we lose part of what makes New York unique.”
Although they provided the best estimates available, the authors said their methodology could have overlooked some species, for example by not sampling agricultural habitats.
Surveyors confirmed the absence of the rusty patched bumblebee (Bombus affinis), which the US declared an endangered species in 2017 and is believed to be no longer present in New York. They found only a single specimen of the red-bellied mine bee (Andrena erythrogaster), which was classified as severely in decline.
“This is the kind of thing we worry about,” Danforth said. “This bee was historically present in upstate New York, very common, and is now off the radar.”
On the other hand, Danforth and Van Dyke were reassured to find the hawthorn mine bee (Andrena crataegi), an apple pollinator that seems to be abundant even in non-agricultural habitats. And while they remain rare and risky, surveyors collected specimens of all three oil bee species (genus Macropis) previously collected in New York. The bees rely solely on oils obtained from yellow loosestrife plants to coat their brood cells and provide for their offspring.
“While they are probably not as common as they were in the past,” Van Dyke said, “isolated populations of these specialized bees can still be found in wetland habitats in New York.”
The research could prompt policymakers to update lists of threatened and endangered species, thereby protecting the habitats of the most vulnerable species. The report highlights several other conservation and land management practices that can benefit pollinators, including reduced use of pesticides and herbicides; control of invasive species; discouraging high beehive densities that could transmit disease; minimizing light pollution; and more careful roadside mowing and prescribed burns.
“Once we identify species that are in decline,” Danforth said, “we can make recommendations for preserving habitats and host plants that are critical to supporting those native pollinators.”
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