While out in a southeast Michigan floodplain forest this afternoon I came across this common sawfly (Hymenoptera: Tenthredinidae) hiding in clump of sedge leaves (Carex sp., Cyperaceae). The larvae of these wasp-like insects eat plant material and many species are host-specific, feeding only on particular plants. While some species are economically important pests of cultivated plants, the majority have relatively harmless relationships with their hosts. My first thought was that this sedge may be a host plant for this sawfly species. The sawfly may have been hanging out waiting for a mate, with the female subsequently laying her eggs on the sedge.
On the other hand the sawfly may have simply found the sedge to be a comfortable place to hide from the impending cold. Although the weather has been perfect here for a while, tonight we’re dipping below freezing for the first time in weeks. With the high today only in the 40s F, it seemed as if most insects would be seeking shelter for the night.