D3044: (1st Place) Lifespan and behavioral maturation of honey bee (Apis mellifera) workers expressing Varroa sensitive hygiene (VSH)

The western honey bee, Apis mellifera (Hymenoptera: Apidae) is experiencing heavy mortality due to different biotic and abiotic stresses. One major cause of such mortality is the infestation with the ectoparasite Varroa destructor (Mesostigmata: Varroidae), commonly known as the Varroa mite. Several honey bee lines have been selectively bred for traits linked to low Varroa mite levels, such as Varroa sensitive hygiene (VSH). Several studies have shown that summer workers from Varroa-resistant (VR) and tolerant honey bee stocks differentially regulate the expression of genes associated with several aging hallmarks compared to ones from Varroa-sensitive (VS) stocks. Thus, we hypothesized that summer VR workers have different lifespans and, since worker lifespan is tied to the pace of task progression, behavioral maturation rates compared to VS workers. We investigated this relationship by tracking the lifespan, foraging onset age, and foraging lifespan of summer workers from two VR stocks that display VSH, the Pol-line and Russian stocks, and one VS stock, the Italian stock. We found that summer Pol-line and Russian workers lived longer and foraged much later than their Italian counterparts. The foraging lifespan of Pol-line, Russian, and Italian summer workers were similar, indicating that long lifespans of Pol-line and Russian summer workers might be partially due to delayed foraging onset. Our results provide the first evidence of a potential relationship between Varroa resistance and longevity, independent of Varroa infestation, in honey bee workers. Future work will involve more VR and VS stocks, and colonies per stock to better assess that relationship.