Explanation of Names
Macremphytus MacGillivray 1908
Larvae start out covered with a powdery waxy white coating, which they shed later in the year to become yellow with black cross-stripes or spots on top.
D.R. Smith on distinguishing the larvae: The larva of M. semicornis is not known; larvae of M. lovetti and M. testaceus are very similar. Larvae of the two common eastern species can be separated as follows:
M. tarsatus: both the feeding stages and prepupal stage have a rectangular black mark on each segment.
M. testaceus: the feeding stages are uniformly green (no black marks), though the whitish bloom may make them look white.
Color changes when molting to the prepupal stage; there are black spots on the body (not the rectangular pattern as in tarsatus).
M. lovetti Pacific Northwest; M. semicornis e. Canada & ne. US; M. testaceus and M. tarsatus in e. US & Canada
Larvae bore into wood in fall to pupate and overwinter. In wild conditions this would normally be dead wood on the ground, but they have also adapted to bore into man-made structures. Dave Smith has reared them by giving them corks to bore into.