Scott McArt, a research scientist in the Department of Entomology at Cornell University, is looking to find out why there has been a decline in the bee population.

McArt gave a presentation on the loss of bee colonies at the State University of New York College of Environmental Science and Forestry on Thursday as part of the Adaptive Peaks Seminar Series. During the presentation, he posed the question of why the pollinators are doing so poorly, and explained research he has done to try to determine the answer.

In 2014-15, New York state lost 54.1 percent of its honey bee colonies, which is above the national average, McArt said. This problem is not a problem to only honey bees, as other types of bees and pollinators are experiencing a decline as well.

Bees serve as crucial pollinators. One-third of the food people eat is reliant upon pollinators, while the other two-thirds are somewhat reliant on pollinators, McArt said.

There are six main drivers of pollinator loss, McArt said. They are agrochemicals including insecticides, fungicides and herbicides; pests and pathogens; climate change; lack of habitat diversity; and poor management practices by beekeepers.

While he recognizes these factors individually, McArt said it is important to notice the interaction between the factors, such as agrochemicals leading to an increase in the susceptibility of bees to pests and pathogens.

Pests and pathogens can also be tied to poor beekeeping, he added.

“About 95 percent of beekeepers in New York are hobby beekeepers, and they are new at it,” McArt said. “They don’t know they have to treat for varroa mites. It is not surprising that they are losing over 50 percent of colonies in this state — varroa will wipe out your colony very quickly.”

One of the main research efforts in McArt’s lab is to find the relative importance of the different factors. By knowing this, specific ways of preventing the bee decline can be targeted, he said.

McArt participated in a landscape analysis that suggested the strongest predictor of honey bee colony loss is exposure to fungicides.

Fungicides are the most prevalent residue brought by honey bees to colonies, and this is true for bumble bees as well, McArt said.

If the fungicide load in the pollen is increased, there is an increase in the probability of bees becoming infected with Nosema, McArt said. Nosema is a fungus that attacks the gut of the honey bee, according to the Advance Science website.

This poses an issue, as growers have no restrictions on how much fungicide they can spray during bloom, McArt said.

McArt also discussed an ongoing research project involving 120 experimental hives being placed in 30 apple orchards throughout New York state. The hives were assessed last summer for pathogens, parasites, diet and colony performance before and after pollination and every three weeks.

Researchers determined a 13 percent summer loss rate for the honey bee colonies, which McArt said was typical across New York state.

Once the weather warms up, the research team will assess the hives to determine the winter loss rates. McArt said he is confident the team will be able to pull out a factor that is not pesticides, but added that the team cannot be sure until the winter loss rates are determined.

McArt also talked about his involvement as a science adviser on a task force that was created last summer by New York state Gov. Andrew Cuomo as part of the state’s Pollinator Protection Program.

In January, after listening to the recommendations from the task force, Cuomo proposed $500,000 in the executive budget for the Pollinator Protection Plan. On April 1, specific funding allocations will be unveiled.

Published on March 28, 2016 at 12:14 am

Contact Taylor: tnwatson@syr.edu