Gadira petraula

Key Features

  • Gadira petraula is a small moth (Lepidoptera: Crambidae).
  • The wingspan is 16.5–20 mm for males and 9.5–11.5 mm for females.
  • The forewings are white, tinged with greyish and irrorated with blackish. The hindwings are grey, but darker posteriorily and with a pale line just before the hindmargin.
  • It is very similar to Gadira leucophthalma, and on Banks Peninsula the two species can be found together.
  • The forewing dorsum (trailing edge) is mostly unicolorous whitish to grey in G. leucophthalma, whereas it is patterned in grey and black in the slightly smaller G. petraula.
  • Gadira petraula has a short-winged female in contrast to G. leucophthalma.

Distribution and Habitat

  • Gadira petraula is found in the northeast of the South Island as far south as Banks Peninsula.
  • It inhabits rocky places from steep rock faces to mountainous rocky ridges and pavement, all with a cover of lichens (on whch the lavae feed).


  • Loss of habitat due to earthquakes.
  • Disturbance of habitat and fragmentation of populations as a result of road-making, farming practices and stock rubbing against rocks.
  • The flightless female has limited dispersal ability.

Management Opportunities

  • Protect rocky habitat from disturbance.

Monitoring Options

  • This species is difficult to monitor due to its rarity.
  • A standardised count of larval feeding signs, using the conspicuous webbing of the mature larvae as an indicator, can be used.
  • Undertake monitoring in September.

Further Information and Support

  • Landcare Research Threatened species Factsheet.
  • Patrick B.H. and Dugdale J.S. 2000. Conservation status of New Zealand Lepidoptera. Science for Conservation 136. Department of Conservation, Wellington. 33 pp. Link.