Megachile inimica

Taxonomy

Megachile inimica is in the subgenus Sayapis within the genus Megachile. The genus Megachile is known by the common name “leafcutter 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 inimica was recorded in Minnesota for the first time through the Bee Atlas project in 2018 blocks! We found nests in two locations in Bee Atlas blocks in southern Minnesota, and nests in a third location in 2023.

Description

Megachile are primarily characterized by having large chewing mandibles and scopae (pollen-collecting hairs) under females' abdomens. Megachile inimica is closely related to Megachile pugnata, and looks similar at first glance. Like many Megachile species, M. inimica 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, and the males have elaborately modified forelegs with yellow coloring and hair extending from the lower portions. (see pictures)

Nest Structure

Megachile inimica use cut whole leaf pieces, chewed vegetation, and soil particles to make partitions between cells in their nests. Plugs are made from cut whole leaf pieces covered with a mixture of chewed vegetation and soil particles. In Bee Atlas blocks, the plugs had grass or wood fibers pressed into the outer surface.

Hole Sizes

M. inimica nested in column 2 (1/4" - 5/16") holes and upper column 1 (3/8") holes in Bee Atlas blocks.

Voltinism

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

Activity Period

We have only a small amount of information on nesting dates, but it appears that M. inimica may nest later than other Megachile in Minnesota.

References

No information at this time.