Nesting biology and foraging patterns of the solitary bee Melissodes rustica (Hymenoptera: Apidae) in northwest Arkansas

Field observations of nesting behavior and foraging activity of the solitary bee Melissodes rustica (Say) were made at a nesting stte in northwest Arkansas. The nesting phenology is unusually late in the year for bees, with females emerging in mid- to late September and provisioning burrows until the first hard frost in late October or early November. More than 200 females constructed and provisioned individual burrows at the aggregation. Daily actively patterns were closely correlated whh surface soil temperature and wind speed. Females made six to seven foraging trips per day, all of which included pollen provisions except the last. Pollen was apparently gathered from the genera Aster and Erigeron in the family Asteraceae. Trip duration increased later in the day, as did the time spent in the burrow between trips. Hence, females spent more time collecting pollen and took longer to dispose of the pollen as the day wore on. On the last trip of the day, females returned without pollen. There was little variance among the continously observed females for any of these patterns. Females continued to enter a single burrow for more than 10 days, and provisioned more than one cell per burrow. No communal nests were observed and no nest parasites (e.g., Triepeolus) were collected from the aggregation. We speculate on possible causes of the late nesting phenology of this bee.