|Schäffler, I; Dötterl, S: A day in the life of an oil bee: Phenology, nesting & foraging behavior, Apidologie, 42, 409-424 (2011)|
Little is known about the bionomics of solitary, ground-nesting bees. We established a population of the oil bee, Macropis fulvipes, in a flight cage and recorded the emergence phenology, sex ratio, nesting behavior, and foraging behavior of individually marked bees. The population was protandrous and the sex ratio was balanced in three of the four observation years. The date of first emergence varied even though the sum of temperatures before emergence was similar across years. Adults of both sexes fed on the pollen of Lysimachia punctata host plants. Females additionally visited flowers to collect oil for the nest-cell lining, as well as oil and pollen for larval provisions. Duration of collecting trips, flower visits, and nest stays were influenced by the reward collected. Bees required 12 collecting trips and 460 visitations to flowers to complete a single cell. Therefore, to sustain a viable population of 50–500 individuals, 20,000–200,000 flowers are required. Our study shows that observations in a closed system can provide new insights into the bionomics of bees.