OUR SOUTH WEST Home Page    Millennium Archive Home Page

Species Mole cricket - gryllotalpa gryllotalpa, cricket
Habitat COASTAL FLOODAND AND GRAZING MARSH
Background and status The most distinctive features of the mole cricket (35-46mm) are its highly adapted forelimbs, which are specially designed for digging and, unlike other crickets, they do not possess an ovipositor (an egg-laying tube). Both sexes are dark brown with a fine covering of velvet hairs, although the vein pattern in the middle region of the male's forewing differs from the female, the former like a open tuning fork.

Mole crickets are active throughout the year, but are restricted to damp loose soils, where they feed on insect larvae, cockchafers, owlet moths and worms.

Their song, a continuous churring(rrrrr...) sound, is similar to that of the nightjar, or grasshopper warbler, and is usually made by the male at the entrance to his burrow. Like bush crickets, they can detect sound by sense organs located in their knee joints of their fore legs.

In late spring, the female takes up to two to three weeks to lay between 100 -200 eggs, which she deposits in an underground chamber. Here she protects them from predators and inhibits potential fungal infections by regularly licking the eggs.

The hatchlings emerge within two to three weeks to feed on humus and young roots. Being Hemimetabola insects (those that do not under go a complete metamorphosis) there is no pupa stage, and reach maturity within three years.

The mole cricket occurs throughout much of Europe, north Africa and western Asia, but is thought to be declining throughout its range. In the UK the species used to occur in 33 vice-counties, mainly in southern England (also in southern Wales, western Scotland and Northern Ireland). By the mid 20th century its range had contracted substantially to Dorset, Hampshire and Surrey. It may now be extinct, with the last record of a solitary specimen at Wareham, Dorset in 1988, but there have been several unconfirmed records since.

Main Threats

Intensive mechanical cultivation or drainage of soils in arable and horticultural systems.

Lack of suitable grazing or cutting management in damp meadows, allowing the development of tall vegetation which makes the underlying soil too cold for breeding.

Heavy insecticide use.

Conservation and targets

Locate and safeguard any surviving colonies by the year 2000.

Establish breeding colonies of the cricket in captivity by the Year 2000.

If feasible, identify or establish 20 self-sustaining colonies throughout the cricket’s former range by the Year 2005.

Encourage sympathetic management of known or potential sites.

Consider targeting an appropriate land managment scheme such a Countryside Sterwardship, the Habitat Scheme or Environmentally Sensitive Areas to any area found to support the species, to encourage natural colonisation or to facilitate translocation.

Use this species to highlight the problems of the loss of wetland edge.