New Zealand has an unusually high number of wingless, or at least flightless insects whose Australian relatives may be winged. The stick insects (order Phasmatodea, 21 species) are all wingless, as are wētā and most grasshoppers and crickets (of 109 species, five are winged).
Grasshoppers and crickets
Large, short-winged, flightless grasshoppers are extremely abundant in the tussock grasslands of the South Island, where their feeding can have a significant impact on herbaceous plants. New Zealand’s mole cricket or honi (Triamescaptor aotea) is the world’s only mole cricket without wings. Elsewhere, these burrowing insects rub their wings together to produce a loud mating call, but in New Zealand they are silent. It is not known how the voiceless species seeks a mate.
Flightlessness is common in moths (usually only the females), as it is in beetles, wasps, cockroaches, earwigs and stoneflies. On the subantarctic islands nearly 40% of insects have lost the ability to fly.
Cannibalistic tiger moths
Being wingless, the female alpine tiger moth Metacrias remains in her cocoon, surrounded by the eggs that she has laid. The tiny hatchling larvae then proceed to eat her. Her energy is recycled to give the larvae a strong start in life – as herbivorous caterpillars.
Flightlessness in stoneflies (order Plecoptera) is associated with low temperatures and high winds. In southern New Zealand, especially where rainfall is high, many stoneflies have left freshwater streams to live among snow tussock or under stones. The adults of 25 of the 104 New Zealand and subantarctic species are wingless or have reduced wings. This contrasts with Australia, where only one of the 196 species is flightless.