Gadira petraula is a species of moth in the family Crambidae. This species is endemic to New Zealand and is only found in mid Canterbury. G. petraula inhabits coastal, montane and low alpine rock sites. The larvae live in rock crevices in a silk shelter from which they emerge to feed. Their host plants are moss or lichens. The adult female is flightless and the male is on the wing in March. This species is classified as "At Risk, Naturally Uncommon" by the Department of Conservation. The 2010 and 2011 Christchurch earthquakes destroyed much of this species preferred habitat. Rock climbers cleaning rocks of the larval host plants are also a threat to the survival of this species.
