Eucnemidae

COLEOPTERA > POLYPHAGA > ELATEROIDEA > Eucnemidae

A small family of rarely sighted, extremely secretive woodland beetles that are represented in Britain by just seven species, although only four of these appear to have been officially recorded in recent years.

The general body shape is very similar to that of their click beetle cousins in the Elateridae family and, certainly in respect of species such as Epiphanis cornutus and Hylis olexai, could easily be mistaken for a regular click beetle until you take note of the unusual form of the antennae; notably the offset second segment, but in conjunction with specific features for each species. The two other forms that could possibly be encountered, namely Melasis buprestoides and, if you were really lucky, Microrhagus pygmaeus, have pectinate (toothed) or long serrate antennae and, in respect of that feature alone, are not likely to be misidentified.

Melasis buprestoides is the most frequently observed member of the family but, even so, there are only around 160 confirmed records nationwide and, checking again at the time of this latest update, there have been very few in recent years. I'm sure there are more awaiting verification, but the available data still provides a useful indicator regarding the general scarcity of these species.

It's a distinctive species with the pronotum broadest at the front angles which project forward (rounded in males, but more pointed in females), a head that is largely hidden when viewed from above, and a body that is covered in a fine yellow pubescence, particularly noticeable around the anterior edge of the pronotum. The eccentric placement of the second antennal segment can be clearly seen in the first (dorsal view) photo, and with segments 6-10 pectinate in the male, but serrate in the female. The individual feature here was found on the underside of a piece of Beech deadwood and was around 8mm long.

Epiphanis cornutus is a particularly scarce and apparently local species with, at the time of writing, only 50 or so registered sightings on the NBN Atlas database from across the whole country, half of which are unconfirmed, and with none reported from Dorset, Hampshire or Wiltshire. It would suggest that the individual I found on low-growing vegetation in Horton Wood might be questionable, but the photographs featured here were examined by a well-published beetle expert and then subsequently by one of Europe's leading authorities on click beetles. Initially there were thoughts that it may have been the extremely rare, currently unlisted, Dromaeolus barnabita, but later dismissed, and in respect of the form and length of the final antennal segments positively confirmed as Epiphanis cornutus rather than the even rarer, but not dissimilar Hylis olexai.

The other two species that have been mentioned here Microrhagus pygmaeus and Hylis olexai have 74 and 21 records respectively, but significantly some twenty or more reported sightings of the former have been during the last few years, including a couple from my wider general area, so Microrhagus pygmaeus is definitely a species that I'm going to be looking out for as I doubt whether many casual observers will ever have seen three different members of this family. From illustrations and the few photos I've seen it has splendid long, strongly pectinate in the female, and serrate in the male, antennae that would be more suited to a cerambycid longhorn beetle. I believe that they're most likely to be found in ferns under oak trees.

Updated, April 26 (v.2)