| Varroa destructor | Nosema ceranae |
---|---|---|
Type of parasite | ectoparasite | endoparasite |
Mode of action | Sucks hemolymph/transmits viruses | Attacks epithelium of the gut |
Mode of transmission | Enters brood cell before operculation; phoresis-carried between cells by adult bees (males and females) | Oral transmission between workers, matrices of the hive |
Stage(s) attacked | Nymph/adult | Adult |
Physiological effects | Reduced weight, metabolism, vitellogenin titers, and proportion of normal hemocytes; increased ecdysteroid titers [24, 25] | Increase oxidative stress; degeneration of gut epithelium [26]; reduced vitellogenin level [27]; induces pheromone (ethyl oleate) production [28] |
Lifespan decrease [12] | Lifespan decrease | |
Behavioral effects | Impaired orientation [22] | Impaired orientation [29] |
 | ||
 | Faster habituation and lower response probability to odor stimulus but no change in sucrose response [30] | Increased sucrose response based on PER test [31] |