The wart-biter (Decticus verrucivorus) is a bush-cricket in the family Tettigoniidae. Its English and scientific names derive from the age-old practice of using the cricket to bite warts from the skin.
Adult wart-biters are 31-37 mm long, with females being significantly larger than males. They are typically dark green in colour, usually with dark brown blotches on the pronotum and wings (a dark brown morphotype also occurs). The female has a long and slightly upcurved ovipositor.
The Wart-biter has a song consisting of a rapidly repeated series of short bursts of clicks, sometimes lasting for several minutes.
Wart-biters normally move about by walking; they rarely fly, except when frightened. Most can only fly 3 to 4 meters at a time.
Wart-biters need a mosaic of vegetation, including bare ground/short turf, grass tussocks, and a sward rich in flowering forbs. They prefer areas that are not heavily grazed. The species is thermophilous, and tends to occur on sites with a southerly aspect.
The wart-biter lays its eggs in the soil; these eggs normally hatch after two winters. It then passes through seven instar stages between April and June. The adult stage is reached in the beginning of July. Wart-biter populations peak in late July and early August.
This species occurs throughout continental Europe, except the extreme south, ranging from southern Scandinavia to Spain, Italy, and Greece. It is also found in temperate Asia, as far east as China. Geographic features such as mountains have fragmented the species, leading to a wide range of forms and numerous subspecies.
The population of wart-biters has declined in many areas of northern Europe. In Britain, it is a highly endangered species; in 1990, some sites had fewer than 100 adults. The species is the subject of a United Kingdom Biodiversity Action Plan.