Table 1 Comparative pathologies of Varroa destructor and 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]

Accelerated maturation [11, 12]

Accelerated maturation [13, 14]

Faster habituation and lower response probability to odor stimulus but no change in sucrose response [30]

Increased sucrose response based on PER test [31]