Four common species of bumblebees in central Maine each utilized the nectar from a great variety of both native and exotic flowers. The number of individuals that utilized a nectar resource was directly related to supplies available. Seasonally, ° 92% of the “standing crop” of food energy available per day was utilized in 1972. No interference competition was observed, and competition was primarily exploitative. Small wild bees generally foraged at high temperatures from the small food rewards left after Bombus exploitation. Overlap in resource utilization in the guild of bumblebees was avoided by differences in tongue length. Open (short—corolla) flowers were visited primarily by short— and secondarily by long—tongued bumblebees. Deep—corolla flowers were visited primarily by long—tongued bumblebees. Pollen flowers were utilized more by short—tongued than by long—tongued bumblebees. However, the bumblebee forager spectra on given flower species varied from one locality to the next as well as seasonally. Colony polylecty is probably a necessary correlate of social behavior, given short blooming times of the host plants relative to the long durations of the colony cycles. In turn, colony polylecty of eusocial bees may decrease species richness in the bee community due to competition.