Lucanidae
   Although worldwide an extensive family of almost 1000 species there are only eight european species of which 3 occur in Britain. They are all very distinctive insects which become instantly familiar and will not be misaken for any other group. The Stag beetle, Lucanus cervus L., is not (yet) on our Watford list despite descriptions from people claiming to have seen the species locally but we remain optimistic as we have recorded it a few miles south in Uxbridge, Cowley (especially) and Hayes where it is common. Although the species is xylophagous and variously associated with woodland this is perhaps not the best habitat to record them as, in our extensive experience, they seem very much at home infesting large dead or dying tree stumps near human habitation e.g. in large gardens, alleyways or wasteland. The species is attracted to light and on many occasions we have sat in pub gardens on summer nights watching them, sometimes in numbers, flying around bright tungsten spotlights. Our most recent nocturnal expedition to see this species was in 2005 to Cowley, Middx when, by torchlight, we saw many males flying along the wooded borders of a large lake around midnight.
   Adult lucanids burrow into wood to lay eggs, all species are polyphagous (generally angiosperms) and larvae are long lived e.g. more than three years in Lucanus. All are common where found across England and Wales becoming rarer northwards although Sinodendron can be elusive. They are best searched for at night when large numbers may be found, during the day Dorcus may be found under logs or in bark crevices, Sinodendron flies in hot sun or may be found crawling on trunks. Although Dorcus and Sinodendron occur throughout the year, warm sunny days and humid evenings are the best time to find them.
    10-75mm. Mandibles well developed and visible, in male, Lucanus enlarged and used for competing with other males, female mandibles normal. Antennae genticulate and asymetrically clubbed, the segments forming this are thick and not close fitting (cf Scarabaeidae, Geotrupidae). Tarsi 5 segmented, claws robust and with a well developed bisetose empodium between , this is absent or very small in other Scarabaeoidea families. 5 visible sternites.
   Identification is straightforward, Jessop, Britton and Joy all deal with the group as do many colour guides. There are several fairly recent accounts of Lucanus distribution but Colin Pratt's extensive review is a must for anybody interested in the species.

Clarke, J.T., 1966. The distribution of Lucanus cervus (L.) in Britain. Ent.Mon.Mag.. 102:199-204
Hall, D.G. 1970. Lucanus cervus (L.) in Britain. Ent.Mon.Mag. 105:183-184.
Pratt, C.R. 2003. A modern review of the history of the Stag beetle, Lucanus cervus (L.) in Great Britain. Booth museum of Natural history, Brighton. (CDROM).


Sinodendron
cylindricum

Sinodendron
cylindricum

Dorcus parallelipipedus F

Dorcus parallelipipedus M

Lucanus cervus