Rare native beetle under threat
THE sword of Damocles hangs over a fine native beetle, which may cease to exist within months! The rare ground beetle
Holcaspis brevicula (family: Carabidae) has the attractive shape and sculpturing typical of its family and is about a centimetre long, dark brownish black, and flightless. It occurs only in a small area of the Canterbury Plains in Eyrewell Forest, northwest of Christchurch, between the Waimakariri and Ashley rivers. Holcaspis species generally inhabit forest.
The original vegetation in this beetle’s habitat was low forest and kanuka, which was mostly felled and replaced by Pinus radiata plantation 84 years ago. Despite the pine trees having been planted, felled, harvested and replanted at least three times, H. brevicula has managed to live on in the plantation. Tiny relicts of kanuka within this area are far too small for the beetle to survive in those places alone.
A proposed dairy conversion would see all of the pine trees felled and the habitat replaced by pasture for 14,000 cows, an action that would drive the officially ‘‘critically endangered’’ H. brevicula to immediate extinction. This would be a sad and morally dubious outcome, given that we are currently living through the humancaused sixth great mass extinction event of life on Earth. A sufficient area of forest should be left for the survival of H. brevicula.