UNIVERSITY PARK, Pa. — About one-third of the food eaten by Americans comes from crops pollinated by honey bees, yet the insect is dying off at alarming rates. In one year alone, between April of 2019 and April of 2020, one study reported a 43% colony loss in honey bees across the United States.
A new study led by Penn State researchers provides preliminary insight on the potential effects of several variables, including some linked to climate change, on honey bees. Their findings show that honey bee colony loss in the U.S. over the last five years is primarily related to the presence of parasitic mites, extreme weather events, nearby pesticides, as well as challenges with overwintering, according to a new study led by Penn State researchers. The study took advantage of novel statistical methods and is the first to concurrently consider a variety of potential honey bee stressors at a national scale. The study, published online in the journal Scientific Reports, suggests several areas of concern to prioritize in beekeeping practices.
“Honey bees are vital pollinators for more than 100 species of crops in the United States, and the widespread loss of honey bee colonies is increasingly concerning,” said Luca Insolia, first author of the study, a visiting graduate student in the Department of Statistics at Penn State at the time of the research, and currently a postdoctoral researcher at the University of Geneva in Switzerland. “Some previous studies have explored several potential stressors related to colony loss in a detailed way but are limited to narrow, regional areas. The one study that we know of at the national level in the United States explored only a single potential stressor. For this study, we integrated many large datasets at different spatial and temporal resolutions and used new, sophisticated statistical methods to assess several potential stressors associated with colony collapse across the U.S.”
The research team, composed of statisticians, geographers, and entomologists, gathered publicly available data about honey bee colonies, land use, weather, and other potential stressors from the years 2015 to 2021. Because these data came from a variety of sources, they varied in resolution over both space and time. The weather data, for example, contained daily data points for areas only few square miles in size, but data on honey bee colonies was at the state level for a several-month period.