Doctoral candidate Samuel Ramsey has been named both the Judge’s First Place and People’s Choice award winners in the annual Three Minute Thesis (3MT) contest, sponsored by Universitas 21 (U21), a global network of leading research universities. Ramsey, a doctoral candidate in the Department of Entomology, conducts research on a tiny parasitic mite, Varroa destructor, which is the single biggest contributor to the decline in health of honey populations worldwide. Originating in Asia, the invasive Varroa mite is wreaking havoc on honey bee colonies, both by feeding on adult and immature bees and by serving as a vector for five debilitating viruses.
For nearly 50 years, researchers have believed that the mite fed on the hemolymph (the “blood”) of the honey bee. Ramsey has done extensive research on the feeding habits and nutrition of the Varroa mite that provides strong evidence that this model is incorrect, and that current methods of controlling the parasite are not only ineffective, but may contribute to pesticide resistance.
Ramsey’s research establishes that the mites are primarily feeding on the honey bee’s fat body tissue—an organ in insects that serves a similar role to the human liver. Since several existing systemic pesticides were formulated assuming the mites fed on hemolymph, this discover explains why these pesticides were never successful in controlling the mites. The mites never would have ingested enough to kill them, but this frequent exposure may contribute to future resistance. Ramsey’s work also explains why honey bees suffer so many negative consequences from a parasite we believed was only consuming a small amount of their blood. His discovery will enable researchers to develop more targeted control techniques that could help restore honey bee populations worldwide