Nosema ceranae appears to be more virulent than Nosema apis. In other words, it is more likely to kill an entire colony. A microscopic examination of the spores shows that Nosema apis spores are usually “race track” ovals, while Nosema ceranae are slightly smaller and almond-shaped. Also, the two species differ in the number of coils formed by the polar filament inside the spore. However these differences are not always reliable indicators. Tests of the Nosema DNA are used when it is necessary to be certain of the species.
- Tom Webster, Kentucky State University
Bee Informed Partnership