From one bee to another

Their size may deceive you, but bees easily earn their reputation as a vital component in agricultural and natural systems. Honey bees pollinate numerous fruits, nuts and vegetables, and the bee industry has an estimated annual value of $15 billion.

Researchers at MSU, including Michelle Flenniken, Ph.D., along with scientific collaborators from Israel, co-discovered a virus that infects mining bees and honey bees. The new virus was named Andrena associated bee virus-1, or AnBV-1, since the team determined that the virus was most widespread in mining bees —part of the family Andrena.

“It is important to investigate the impact of viruses on bee health and longevity, since in many regions of the world there have been high annual losses of honey bee (Apis mellifera) colonies and local population declines of other bee species, including mining bees (Andrena),” Flenniken said.

Flenniken is an associate professor in the department of plant science and plant pathology in MSU’s College of Agriculture. According to Flenniken, her lab on campus aims to “understand the impact of viruses on honey bees at the colony, individual bee, and cellular levels with the long-term goal of mitigating the number of honeybee colony losses that are associated with virus infections.”

Flenniken joined the project when she was contacted by Israeli researchers Nor Chejanovsky, Ph.D., and Yael Mandelik, Ph.D. Together, with additional help from Asaf Sadeh, Ph.D., funding was obtained from the United States-Israel Binational Science Foundation (BSF), which promotes scientific relations between the U.S. and Israel to investigate the ecology of bee viruses and, more specifically, virus transmission between different bee species in the same geographic area and the factors that may influence virus transmission.

More than 1,300 bee specimens from 14 sites in the central part of Israel were collected, along with the two most abundant bee species (mining bees and honey bees). Members of the Flenniken Lab, including Katie Daughenbaugh, Ph.D. and MSU doctoral students Alex McMenamin and Brian Ross, worked with Charles Carey, Ph.D., a bioinformatic specialist, to quantify virus prevalence and abundance in the bee samples. They also conducted RNA sequencing data analysis and carried out laboratory-based experiments in which the new virus was propagated. Tanner Wiegand, a Ph.D. student at MSU, determined the phylogenetic relationship of AnBV-1 and other insect viruses. With the collective efforts of MSU and Israeli researchers, a statistical model was created that examined the roles of ecological factors, including floral diversity and abundance, in the transmission of the virus.

“[Our data] indicated that AnBV-1 infection prevalence in honey bees was greater in habitats with low floral diversity and abundance, and that interspecific virus transmission is modulated by the floral community in the habitat,” Flenniken said. “These results suggest that land management strategies that aim to enhance floral diversity and abundance may reduce AnBV-1 spread between co-foraging bees.”

In the meantime, it is unclear what the impact of the virus is on bee health. Flenniken said the virus is not necessarily of immediate concern since the virus and bee hosts have likely co-evolved for years. That said, since viruses are obligate intracellular pathogens —pathogens that reproduce inside the cells of the host— the virus may be taxing on the bees.  As a result of the virus being identified, members of the Pollinator Health Center will further study the impacts of the virus on bee health at cellular and individual levels. In addition, the team will likely carry out AnBV-1 testing on bee specimens from other locations, including Montana, and look for the virus genome in existing sequence databases.

To view the teams’ published paper, visit https://www.mdpi.com/1999-4915/13/2/291.