Megachile frugalis

Taxonomy

Megachile frugalis is in the subgenus Sayapis within the genus Megachile. The genus Megachile is known by the common name “leaf cutter bees” because many members cut out circular or oval pieces of leaves and use them to line their nests. There are some exceptions; some Megachile use tree resin and others use masticated vegetation and mud in addition to leaf pieces. Megachile frugalis was recorded in Minnesota for the first time in 2018, through the Bee Atlas project! We found a nest in one location in a Bee Atlas block in southern Minnesota.

Description

Megachile are characterized by large chewing mandibles and scopae (pollen-collecting hairs) under females' abdomens. Megachile frugalis is closely related to Megachile pugnata and Megachile inimica, and looks similar at first glance. Like many Megachile species, M. frugalis is a mostly dark bee with light hair bands across the females' and males' abdomens. They are a large Megachile, about the size of honeybee workers. However, unlike M. pugnata and M. inimica, the males do not have elaborately modified forelegs. (see pictures)

Nest Structure

The nest structure of Megachile frugalis was described for the first time through the Bee Atlas project. Like M. pugnata and M. inimica, M. frugalis use cut whole leaf pieces, chewed vegetation, and soil particles to make partitions between cells in their nests. The nest contained an empty vestibule between the last cell and the outer plug, which was made from a single layer of chewed leaves mixed with soil particles. (see pictures)

Hole Sizes

The one M. frugalis nest we found was in a lower column 2 (5/16") hole in Bee Atlas blocks.

Voltinism

M. frugalis appears to be univoltine in Minnesota, meaning they complete 1 generation per year.

Activity Period

We have observations from only one M. frugalis nest in the Bee Atlas project. That nest was completed between the 3rd week in July and the second week of August.

References

No information at this time.