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

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

Congreso; III Congress of the Latin American Association of Chemical Ecology; 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 (tipo de adsorbente?) before analyzing by means of GC-MS. Differences between infested and non-infested brood is being evaluated by comparing chromatographic profiles. Results: Results suggest differences between the profiles obtained from infested and control brood as well as among different infestation times. Though, analysis is still undergoing. We expect higher differential peaks in the case of infested brood with respect to the control, and increased differences along advancing infestation. We seek for characteristic peaks in infested brood that trigger the hygienic behavior in honeybees through the infestation with V. destructor . 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.