Researchers from the University of New Hampshire conducted a study to document declines in about 100 wild bee species critical to pollinating crops throughout New England. What they discovered, according to the study, was a collapse in the wild bee population across the state, reported AP.

Researchers analyzed 119 species in the state from a museum collection at the college dating back more than a century. Sandra Rehan and Minna Mathiasson published the study in the peer-reviewed journal called Insect and Conservation Diversity this month. They concluded 14 species found across New England were on the decline by as much as 90%. Several of the species include leafcutter and mining bees.

"We know that wild bees are greatly at risk and not doing well worldwide," Rehan, assistant professor of biological sciences and the senior author on the study, said in a prepared statement. "This status assessment of wild bees shines a light on the exact species in decline, besides the well-documented bumblebees. Because these species are major players in crop pollination, it raises concerns about compromising the production of key crops and the food supply in general."

The AP noted that wild bee populations across the world are in decline, and scientists have blamed a wide range of factors including industrialization, insecticides, herbicides, parasites, disease, and climate change. Bees are crucial for pollination, and about one-third of the human diet derives from plants that are directly pollinated by bees.

Greg Burtt, founder of Burtt’s Apple Orchard in Cabot, Vermont, told the AP that his farm relies heavily on wild bees for crop production.

"Making sure that pollinators in the area are healthy and doing well is definitely something we’re concerned about," Burtt said.

Jeff Lozier, a bee expert from the University of Alabama who didn't participate in the study, said the results are a critical step in expanding research into lesser-known species of bees. He cautioned that the study relied upon bees in a museum that were not collected "for the purpose of large scale population surveys."

"The most important use of the data in my view is in providing a baseline set of hypotheses for groups of species that are potentially declining or stable across a much greater set of species than is usually examined, which can then be investigated in more detail to determine why they may be changing," Lozier said in an email interview. "This study doesn’t really determine the why quite yet, but gives us a reference point for further study."

The study noticed that half of those wild bees on the decline were located in higher elevation regions like the White Mountains than in the state's coastal areas. The study said as the wild bees shift northward, some of the species don't have the same kind of flowers and plants to pollinate.

"They have nowhere else to go," Rehan said. "That is the biggest concern."

Rehan warned as wild bee populations collapse so will crop yields, which could produce food shortages across the country. She says wild bees are facing similar threats that have also caused honeybee populations to plunge - including the overuse of pesticides and herbicides, a lack of seasonal wild plant diversity and volatile weather.