Thanasimus formicarius, also known as the ‘Ant Beetle’ or ‘European red-bellied clerid’ (fancy!), is a small but striking species of Beetle native to the UK. It is not un-common but being small and selective in its choice of habitat it is rarely seen in even more rarely reported!
The Beetle is typically found in coniferous woodland where it is a predator of Bark Beetles and is considered to be a natural control against infestation and damage caused by those species.
Both the larval and adult stage of the beetle feed on Bark Beetle. The pink larvae live beneath the bark of the tree within the galleries (tunnels) produced by Bark Beetle larvae. They can spend up to 2 years in their larval stage before pupating into the adult stage. The adult stage can then live up to 10 months during which time it feeds on the adult Bark Beetle and finds a mate. The adult Beetle will then lay its eggs below the bark of a suitable coniferous tree.
Adult Thanasimus formicarius are coloured red, white and black and have large powerful mandibles for catching and tearing into their prey. This species has been previously recorded on the Sefton Coast at Ainsdale NNR and Ince Blundell but the most recent, that at Ince Blundell, was from 1989!
That was until Louise Mills, Environmental Education Tour Guide at the National Trust spotted it and posted her photos in the Merseyside BioBank Active Naturalist Facebook Group to request an identification.
I found this walking around on my arm at the information trailer at the National Trust Formby this Saturday. It was very small, maybe about a centimeter max in length. I also found another one yesterday which was only half the size again… This one had a very red thorax underneath as well as where it joins the head under the wing cases… – Louise Mills
Steve McWilliam named the beetle as Thanasimus formicarius and the photos were sent to Don Stenhouse, our local Beetle expert based at Bolton Museum, who confirmed the ID!
It is Thanasimus formicarius and the location is spot on… – Don Stenhouse
Louise’s sightings on the 10th and 11th of September 2016 are the first reported sighting of this species in 27 years! Well done Louise!
