Carabids are beetles (Order: Coleoptera) and so possess two characteristics that distinguish them from insects of other orders:
- Hard forewings (elytra) that cover the abdomen and meet centrally without overlapping;
- Biting mouthparts.
Carabidae can be recognised by a number of general features:
1. Filiforme antennae (in the British sub-families).
2. Five segmented tarsi.
3. Hind coxae forming triangular plates that divide the first sub-abdominal segment.
4. Hind tronchanters are lobed, extending part way along the third hind margin of the femora.
The family Carabidae, commonly called ground beetles, is made up of just over 350 species in Britain and Ireland. Species vary in size from 1.8mm (Elaphropus parvulus) to 35mm (Carabus intricatus) and exhibit a range of colouration. Take a moment to look through our species accounts and picture gallery and you will see that they exhibit an amazing array of irridescent metallic colours.
Carabids are largely noctural, and by day can be found under rocks and stones, in logs and tussocks of grass. They tend to have large eyes, long legs, and strong jaws. Carabids have wide-ranging roles within food webs (Lövei & Sunderland 1996). They are opportunistic predatory feeders preying on soil dwelling insects, including caterpillars, wireworms, maggots, ants, aphids and slugs. They are therefore very important biological control agents within agricultural ecosystems and conserving the natural ground beetle assemblage should reduce the need for chemical controls. However, a recent UK study identified substantial overall declines in carabid biodiversity (Brooks et al. 2012). Three-quarters of the species studied declined, half of which were estimated to be undergoing population reductions of > 30%, when averaged over 10-year periods. This rate of decline is comparable to that reported for butterflies and moths. Although the widespread repercussions of a depletion in such roles for the functioning of ecosystems are poorly understood (Koivula 2011), carabid declines raise concerns for the production of food because their services are particularly valuable to agriculture (Bohan et al. 2011).
Brooks, D. R., Bater, J. E., Clark, S. J., Monteith, D. T., Andrews, C., Corbett, S. J., Beaumont, D. A., Chapman, J. W. (2012), Large carabid beetle declines in a United Kingdom monitoring network increases evidence for a widespread loss in insect biodiversity. Journal of Applied Ecology, 49: 1009–1019. doi: 10.1111/j.1365-2664.2012.02194.x