Attraction to old nest cues during nest selection by the solitary bee Megachile rotundata (Hymenoptera: Megachilidae)

SummaryThe alfalfa leafcutting bee, Megachile rotundata F. (Hymenoptera: Megachilidae), is an important pollinator for the commercial production of alfalfa seed. Poor nest establishment is, however, an ongoing problem for bee managers. Megachile rotundata are solitary yet gregarious bees that nest in pre-existing cavities and are attracted to previously used nests. Nest cells contain several components that may serve as cues for nesting females. In the current study, we sought to: 1. determine if there is a preference for cells that previously held male or female conspecific bees; 2. verify attraction to conspecific whole nest cells; and 3. determine which individual nest components of a cell are attractive to nesting females. In a series of cage and open field experiments, M. rotundata females were allowed to initiate nests in blocks containing whole cells or individual cell components from old nests. Statistical analyses of results verified the attraction to conspecific nest cells, with no preference fo...