Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Other
Publication Acceptance Date: 2/20/2019
Publication Date: 2/21/2019
Citation: Bauchan, G.R., Ochoa, R., Ramsey, S. 2019. How the Varroa mite was discovered to feed on fat bodies rather than hemolymph. Proceedings of the Entomological Society of Washington. https://entomologytoday.org/2019/02/21/inside-look-how-varroa-mite-diet-discovered/.
Technical Abstract: The parasitic bee mite, Varroa destructor is the greatest single driver of the global honey bee health decline. For 50 years, researchers and beekeepers have operated under the conclusion that Varroa feed exclusively on the hemolymph (blood) of honey bees. A recent study using a multi-disciplinary approach of feeding assays, observational analysis and various microscopy technologies use used to test this conclusion. Observational studies of mites feeding on bees showed that the mites primarily feed on the abdomen of the bee. Scanning electron microscopy and transmission electron microscopy revealed that the mites feed on adult bees by puncturing the membrane between the ventral abdominal plates. Fat body and hemolymph tissue were differentially stained in host bees and fluorescence microscopy and confocal laser scanning microscopy studies were used to determine the contents of the host meal consumed by the mite. Fat body tissue was detected as the primary tissue in the mite’s digestive system while only negligible amounts of hemolymph were detected. Finally, invitro feeding studies proved that the mites could only survive long enough to produce eggs if fat body was a component of the feeding system. Collectively, this multi-disciplinary generated a paradigm shift in our understanding of how, where, and what this mite obtains when parasitizing host honey bees. This research provides a path forward for the development of strategies to controlling this major pest of honey bees world-wide.