Taxonomy

Appearance of the field cricket, Gryllus campestris:

Adults:
  • Large
  • Shiny black colour
  • Distinctively large head, particularly in the male.
  • The fore wings, with a yellow basal patch, just cover the abdomen in the male but are shorter in the female. 
  • The hind wings are vestigial in both sexes so flight is not possible.
  • The underside of the hind legs basally is reddish-orange. 

Total body length:

  • Male: 19-23mm
  • Female: 17-22mm

Fore Wing length:

  • Male: 12-14mm
  • Female: 10-14mm

Ovipositor:

  • Female: 8-12mm
Nymphs:

Nymphs are also shiny black with a golden pubescence, with the distinctively large head.

Distinguishing Gryllus campestris from close relatives:

The large head and short wings readily distinguish G. campestris Linnaeus from the closely related southern field cricket, Gryllus bimaculatus De Geer.

G. bimaculatus is occasionally introduced to the UK or released from culture here (it is reared as a food source). However, it has a southern European/North African/Asian distribution and is unlikely to become established outdoors in the UK (Marshall and Haes 1988).