Response of Apis mellifera towards chemical compounds associated with Varroa destructor infested-brood

M. CLARA LIENDO; ROMINA RUSSO; IRINA MUNTAABSKI; LUCAS LANDI; SILVIA LANZAVECCHIA; MARÍA ALEJANDRA PALACIO; JORGE L. CLADERA; ALEJANDRA C. SCANNAPIECO

Congreso; 5th Congress of the Latin American Association of Chemical Ecology; 2018

Varroa destructor constitutes one of the main problems facing the beekeeping. This parasite spends its life in the honey bee nest either on immature stages or on adult bees. Apis mellifera displays a social health mechanism against brood diseases that consists in detect, uncap and remove dead or diseased brood from the hive, the hygienic behavior. The detection and removing of brood infested by worker bees, interrupt the reproductive cycle of the mite and hence limit its population increase in the hive. This behavior would be induced by olfactory cues. In previous studies, we found two novel candidate compounds associated with infested brood that could trigger hygienic behavior: alpha pinene and hexanoic acid ethyl ester. The aim of this research was to evaluate the removal behavior of workers bees towards these two chemical compounds associated to the mite infestation in healthy brood cells. Treated cells were prepared by inserting small filter papers with 2 ul of a compound in two different times of bee brood development: larvae and pupae. Four treatments were applied in 25 healthy larvae: alpha pinene, hexanoic acid ethylester, a mixture of equal parts (Mix) and deionized water (control). After 48 h the number of brood removed cells was recorded. Worker bees removed higher percentages of brood withhexanoic acid ethyl esterand mix than with alpha pinene and control. Also, this tendency was greater when the treated brood were pupae. These results suggest that the stageof brood development and particular odors influence the hygienic behavior.Our results showed new compounds associated to brood infested by V. destructor that triggersthe removal behavior. This information contributes to a better understanding of this social mechanism against the mite and provides tools to the selection of bee strains exhibiting higher tolerance to the parasite.