Evaluation of Antimicrosporidian Activity of Plant Extracts on Nosema ceranae

Nosemosis is one of the most common protozoan diseases of adult bees ( ). Nosemosis is caused by two species of microsporidia; and . is potentially more dangerous because it has the ability to infect multiple cell types, and it is now the predominant microsporidian species in . In this study, we identified two anti-nosemosis plants, and , which reduced the spore development of in spore-infected cells. The most important aspect of our results was that our treatment was effective at non-toxic concentrations. Anti-nosemosis activities of both plants were revealed in honey bee experiments. Specifically, a mixed extract of both and showed stronger activity than treatment with each single extract alone. Although the mechanisms of action of and against are still unclear, our results suggest new medicaments and therapeutic methods to control infection.