Parasite-host interactions between the Varroa mite and the honey bee from Argentina: an approximation to grooming behavior.

RUSSO RM ; MUNTAABSKI I; LIENDO MC; LANDI L; MERKE J; PIETRONAVE H; FAIN H; GALINDO-CARDONA A; LANZAVECCHIA S; SCANNAPIECO AC

San Juan

Conferencia; Puerto Rico Honey Bees and Evolution of Invasive Organisms on Islands; 2019

Varroa destructor is associated with high winter mortality of Apis mellifera colonies in the Americas. One mechanism limiting Varroa population growth in colonies is the ability of some honey bees to groom mites from their bodies. In Argentina, a stock of honey bees from a subtropical region has been obtained after several years of survival without acaricide treatment. In order to explore the contribution of grooming behavior to Varroa-tolerance, we compared two lines (M, mite-tolerant vs C, susceptible). Eleven colonies from each line were evaluated for two consecutive seasons. The number of colonies that survived the winter season was higher in M than in C lines. The dynamics of Varroa infestation were similar between lines, but M maintained the mite loads at lower level. M showed a higher proportion of fallen and damaged mites than C lines through the season. Our results suggest that grooming behavior could explain the difference in Varroa-tolerance between M and C lines, by regulating the mite loads prior to the exponential mite population grown. The level of the fallen mites appears to be a good predictor of grooming and could be used as a selection target of programs breeding for Varroa tolerant honey bees.