Morphological differences in seta across Andrena bee species and sexes

Andrena species are solitary bees that provide important pollination services in both agricultural and native ecological systems. Adult bee specimens gather pollen with their branched hairs, called setae, as primary food source for their larvae. Andrena bees are known for rubbing the underside of their metasoma (abdomen) against flower anthers to collect pollen which they move subsequently to the scopae on their hind leg. Other body parts including the head were not known to be used for pollen collection. Conversely, male Andrena frons have more dense pilosity for unknown reasons. Recently setal morphologies in Bumblebees have been classified. Plumose setae structures were shown as important indicators for species level identification. Plumose structures function to collect pollen, aid heat retention, and possible mechanosensory use. Distribution of plumose setae in Andrena bees would likewise provide insight into their adaptive ecological function.
No studies delve into which setal branching types occur in Andrena and if there is sexual dimorphism amongst these setal types. This study aims to describe the setal morphology of several Andrena species. Describing the setal distribution on metasomal sternites (the ventral plates of the abdomen) and the frontal head regions of female and male specimens; to elucidate possible sexual dimporphism and intra or interspecific differences that might be utilized for species characterization.
By understanding the distribution of setae between sexes and species, it may be possible to better speciate between Andrena bees. This research could provide valuable information for understanding the adaptive ecological functions of these important pollinators.