It came in through the bathroom window

December 17th, 2015

It came in through the bathroom window

    Getting ready for going to the lab the other day, I walked into the bathroom to see a new visitor in the white bathroom sink. Long parallel antennae extended straight forward beyond the head of this beetle, with the very tips of the antennae aimed gracefully outward from the vertical axis of the body. This brownish beetle was flat and slim with a parallel-sided body only about 8 mm long. This was clearly not the normal elaterid that somehow makes it into our bathroom.

In fact, this turned out to be a member of the family Cupedidae, the reticulate beetles, named for the rows of regular punctures that run up and down the elytra. This species, Tenomerga cinerea, had been collected in Ithaca before, with a little over 40 specimens at Cornell. Cupedidae is a small, primitive family that’s not collected very often; the family includes a total of 33 species in 9 genera worldwide. CUIC has 6 of these species in 5 genera, which seems like pretty good representation to me. Mesozoic fossils tell us that there used to be lots more cupedids than now.

The Cornell Insect Collection began in 1871. The first specimen of T. cinerea at Cornell was collected in 1891 and since then, about 1 year in every 3 a specimen destined for CUIC is collected around July or August. About ¼ of the 44 specimens at CUIC were collected at lights and they came from Georgia to Rensselaer Co., NY and from Ohio to Long Island. However, about half of the CUIC specimens were collected around Ithaca, so T. cinerea must find what it needs in our region.

We don’t really know what T. cinerea does to entertain itself most of the time. Cupedid larvae are found mining rotting wood where it’s thought that they have some kind of association with wood rot fungi. Antennae on adult T. cinerea are longer than half the length of their bodies which made me think of the cerambycids being studied in my laboratory. We know little more about the biology of these rare cupedids. Perhaps one of these days, an entomologist will be able to tell us a bit more about their roles as forest decomposers and why the adults have such long antennae.

Ann Hajek--Associate Curator