Bark-Gnawing Beetle from Singapore

Subject: Bewildering Fungus eater
Location: Singapore
September 9, 2014 6:39 am
Hi Daniel
Hope you’re well.
Was wondering if you could help me narrow down an ID for the attached insect. It was on a dead log together with a lot of fungus weevils and fungus beetles so I suspected it liked the fungus too. I’ve never seen anything like it before. As usual when I see something bewildering I think of you 🙂
Signature: David

What's That Beetle???
What’s That Beetle???

Dear David,
Your images are spectacular, and this is truly an odd looking beetle, and we haven’t even a guess at its identity at the time of posting.  Alas, we cannot research this at this time because we must rush off to work.  Perhaps one of our readers has a clue or the time to investigate.  It does appear to be carrying some Mites on the elytra.  The placement of the eyes is quite unusual, almost like those of a frog that lies submerged with only its eyes visible above water.

Beetle from Singapore
Bark-Gnawing Beetle from Singapore

Hi Daniel and David:
My first impression was that it looked like an odd Jewel Beetle (Buprestidae) but I could find nothing similar online. I believe this is actually a Bark-gnawing Beetle (Trogossitidae), a relatively small and obscure family of beetles. The dorsal markings resemble some Leperina (=Lepidopteryx) species, but I think there are too many dissimilarities for that to be the correct genus. I believe it is probably a species of Xenoglena, for which the lack of elytral scales and dorsally placed eyes are diagnostic. Information is generally lacking for Asian Trogossitidae, but Kolibáč (2009) provided a very complete (and technical) description of the family. Google Books provides access to this document – see page 46 for discussion and page 37 for representative pictures of Xenoglena sp.  I have a feeling it could be X. deyrollei, but I have found no image for that species so I really can’t be certain.  If you have difficulty accessing that site the same information for Xenoglena sp. is also provided  Despite the common name for the family, these beetles are actually predatory. According to Kolibáč (2009) “Adults dwell on fallen trees and dry branches, hunting for xylophagous insects. They fly and run at great speed and appear very like some jewel beetles in body shape.”  Regards. Karl


1 thought on “Bark-Gnawing Beetle from Singapore”

  1. Thanks Karl. Your reply is such a fascinating read. I had never seen this beetle before or anything resembling it. Yes I found it on a fallen tree as mentioned. I’m off to do some research on this Trogossitidae family.


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