Researchers receive $1,137,000 to study threats to honey bees

Posted: March 4, 2014

Scientists in the Center for Pollinator Research at Penn State have received three grants from the United States Department of Agriculture and National Science Foundation to study various threats to honey bees, including disease, pesticides, and the extinction and invasion of other species into their habitats.

Investigating Disease

With a $467,000 grant from United States Department of Agriculture, a team of scientists -- including Christina Grozinger, associate professor of entomology and director of the Center for Pollinator Research -- will examine and develop tools to mitigate the effects of a gut parasite, Nosema ceranae, that negatively impacts honey bees and has been linked to colony losses.

"Honey bees play a vital role in the agricultural system because they pollinate about 75 percent of our major global crops, including nutrient-rich vegetables, fruits and nuts," said Grozinger. "The microsporidian parasite Nosema ceranae is widespread throughout the United States and the world. This parasite interferes with the digestive system and metabolic function of honey bees, leading to increased mortality of individual bees, which in turn can profoundly impact the social structure and health of the colony. This parasite is regarded as a key threat to bee health and has been implicated in alarming colony losses."

Grozinger and her colleagues -- which include scientists at the United States Department of Agriculture's Bee Research Laboratory and the University of Kentucky -- plan to use genomic and genetic techniques to improve the current understanding of how Nosema ceranae infects bees and spreads throughout their colonies. They will characterize the genes that enable Nosema ceranae to invade honey bee tissues, and use this information to develop specific therapeutics to reduce the parasite's virulence and the host's susceptibility to infection.

Poring Over Pesticides

With a second grant from the United States Department of Agriculture in the amount of $370,000, scientists in the Center for Pollinator Research will investigate the effects of pesticides on honey bees.

"Modern pesticide formulations, particularly when multiple active ingredients are blended, require proprietary adjuvants and 'inerts' to achieve high efficacy for targeted pests," said Christopher Mullin, professor of entomology. "Recently, we have shown that honey bees are unusually sensitive to organosilicone spray adjuvants and other coformulants used in agrochemicals."

In its project, the team -- which also includes Maryann Frazier, senior extension associate -- will analyze the presence and fate of organosilicone spray adjuvants and other coformulants in bee ecosystems. Specifically, they will (1) identify common 'inerts' in agrochemicals and other environmental chemicals used frequently around honey bees or in their preferred foraging areas; (2) develop analytical methods to monitor and determine the fate of pesticide formulation and adjuvant ingredients within bee ecosystems; (3) determine acute and sub-lethal effects of pesticides, their formulation ingredients, important metabolites, and relevant combinations on bee physiological and behavioral systems; and (4) facilitate integration and communication of results to beekeepers, growers, pesticide regulators, the agrochemical industry, and the research community.
"Knowing relevant environmental levels of adjuvants and 'inerts' would allow improved risk assessment of total chemical loads and exposures for bee pollinators and other non-targets species," said Mullin. "In addition, we anticipate that if 'inerts' are influencing pesticide levels and general hive stress, formulation recommendations can be optimized for use in bee foraging areas."

Examining Effects of Extinction and Invasion

A third grant, funded by the National Science Foundation in the amount of $300,000, will enable researchers to investigate the impacts of extinctions and invasions on community stability and biodiversity. The team -- which includes Colin Campbell, postdoctoral scholar in the Department of Biology; Katriona Shea, professor of biology; and Reka Albert, professor of physics and of biology -- will model perturbations to ecosystem structure, specifically the permanent or temporary removal (extinction) or introduction (invasion) of one or more species.
"This model will allow us to assess which species and ecosystem properties contribute to the susceptibility of an ecosystem to catastrophic failure, and which contribute most to stability," said Campbell.

According to Shea, the need to address the impacts of environmental perturbations is increasingly urgent.

"The addition or loss of species to existing ecological communities can have far-reaching consequences for both the community and the greater ecosystem in which the community is embedded," she said. "For example, the recent, rapid decline in pollinator levels poses a serious risk to global agriculture and food security. This project will advance our knowledge of how these complex systems function; only if we can anticipate the effects of environmental perturbations can we act to prevent or ameliorate undesired outcomes."

Scientists in the Center for Pollinator Research develop and implement integrative, multidisciplinary approaches to improving pollinator health, conservation and management for ecosystems services through research, education, outreach and policy.

For more information, please visit the Center for Pollinator Research.