I have now recorded a fairly complete life cyle of a batch of Osmoderma emericola grubs I collected February 16, 2006 from a large wind-toppled maple. I began finding eggs in the container of adults. Although I never witnessed copulation, the adults like to burrow down into the frass/woodrot almost as much as grubs, and it may be that is where they copulate too.

They eggs were laid only a few at a time by several females and I collected them daily for two or three weeks, kept them separately, and first noticed the hairy little hatchlings May 30. For over a week now I have left recently laid eggs in the container with the adults to see how they fare.

The adults have also expired one or two at a time. I don't know what they might eat in the wild but I gave them a small chunk of watermelon on three occasions, which they seemed to relish. I pickled the dead and they are available for collectors.