Sexually dimorphic responses to monofloral honeys in the small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae)

Of twenty species of beetles across six families and fourteen genera found living within the hives of the western honey bee Apis mellifera, only the small hive beetle (SHB), Aethina tumida, displays attributes characteristic of an integrated parasitic lifestyle. This species is a pest that can cause severe damage to weakened hives. SHB adults tend to disperse over long distances after they eclose and appear to rely on food odors to locate beehives to infest. Thus, we hypothesized that the floral sources of nectars processed into honey stored in hives may influence SHB orientation toward hives and dietary preferences within hives. We carried out preference assays of individual SHB in an arena with several protein patty substitute diets, each of which was prepared with one of three monofloral honeys (white tupelo Nyssa ogeche, black locust Robinia pseudoacacia, and buckwheat Fagopyrum esculentum) or a phytochemical-free control. Male and female beetles displayed different responses to food choices. Female SHB preferred monofloral honey diets (74%) over the phytochemical-free control, and, among the three monofloral honeys, exhibited a strong preference for the white tupelo honey diet over control diets. In contrast, 41% of male SHB in individual assays preferred the control diet over diets containing monofloral honeys. These findings suggest that for males the ability to detect sugar sources is the primary determinant of preference, whereas, based presumably on nutritional requirements in support of oviposition, female SHB may be responsive to a broader range of food-related cues to increase the likelihood of identifying well-provisioned hives.