Olfactory cues involved in hygienic behavior in Apis mellifera to Varroa destructor.

MARÍA CLARA LIENDO; PATRICIA FERNANDEZ; IRINA MUNTAABSKI; MARÍA ALEJANDRA PALACIO; JORGE LUIS CLADERA; ALEJANDRA CARLA SCANNAPIECO

Congreso; III Congress of the Latin American Association io Chemical Ecology- ALAEQ; 2014

Introduction: The infestation caused by the parasitic mite Varroa destructor (Acari: Varroidae) is one of the major problems facing the apicultural sector. Honeybees have a resistance mechanism against brood diseases (e.g, varroosis) that consists in detect, uncap and remove dead or diseased brood from the hive (hygienic behavior). Previous studies showed that the detection of diseased brood by worker bees would be triggered by olfactory cues. The aim of this study was to collect and identify volatile compounds associated with infested bee brood with V. destructor at different times of mite reproductive cycle. Material and methods: Newly capped bee brood was artificially infested with a mite (foundation female). At different times (62 hs, 5 days and 10 days post-infestation) 25 individuals were removed and placed in glass aeration chambers. Volatiles were collected for 24 h on filters containing adsorbent material (Hayesept Q). As a control, in one of the chambers non-infested brood was placed. Volatiles were eluted with metilene chloride, afterwards adsorbed on an SPME fiber before analyzing by means of GC-MS. Differences between infested and non-infested brood have been evaluated by comparing chromatographic profiles. Results: We found differences between the profiles obtained from infested and control brood as well as among different infestation times. Results also suggest differences in the area of the peaks between infested and control brood, and along advancing infestation. The identification of characteristic peaks in infested brood is being undergoing. Conclusions: The results of this study will allow to propose possible candidate compounds or a mixture of compounds that trigger the hygienic behavior in honeybees through the infestation with V. destructor. This information will contribute to understand the mechanism by which bees defend against the parasite, providing information on varroa control strategies and genetic selection of Apis mellifera tolerant colonies.