Story: Insects – overview
Page 9 – Alpine insects
Exposed shrublands, tussocklands and rocky areas above the treeline are home to some of New Zealand’s endemic insects. Many of these are dark with dense hair, which allows them to absorb the sun’s energy. Included among them are butterflies, grasshoppers and cicadas, which could be described as sunbathers.
Black mountain ringlet butterfly
The black mountain ringlet butterfly (Percnodaimon merula) rests on warm rocks or floats lazily in the warm air just above a rock surface. They lay their eggs on stones, and the pupae form under thin, flat rocks that heat up in strong sunlight. Caterpillars feed on blue tussock.
Grasshoppers and cicadas
Large, flightless grasshoppers are common in the alpine zone. The highest-living alpine grasshopper, Sigaus villosus, is grey and covered with short hair, blending into its rocky habitat. It frequently jumps into tarns, where it floats, or onto snow patches, where its long hind legs work like ski poles to propel it to safety.
Bristly, black cicadas, known as Māori cicadas (Maoricicada species), occupy the same habitat. They are the highest-living alpine cicadas in the world.
Insects often have a chemically complex relationship with the plants they eat, and become dependent on a single type of plant. Black and white alpine weevils in the genus Lyperobius depend on speargrass (Aciphylla), a relative of the carrot. Their larvae tunnel inside the taproot, while adults eat the leaves. Seventeen species of large, flightless Lyperobius are distributed throughout the South Island mountains, each eating particular species of speargrass or its near relative, Anisotome.