About Hemideina thoracica (White, 1846)
Adult Hemideina thoracica are large-bodied, with weights ranging from 3 to 7 grams and lengths reaching up to 40 millimeters. Their abdomen is brown, and their pronotum is pale with dark markings that resemble hieroglyphs. This unique body coloration makes H. thoracica easy to distinguish from the parapatric Wellington tree wētā (H. crassidens). Like all other species in the genus Hemideina, H. thoracica has spines on its hind legs that serve a defensive function. Morphometric analysis of spination patterns shows that both H. thoracica and H. crassidens lack the mid-tibial '1/3 back' spine, which sets these two species apart from all other Hemideina species. Compared to all other New Zealand tree wētā (genus Hemideina), Hemideina thoracica has the thinnest femur and tibia. Adults of this species are sexually dimorphic: males have enlarged mandibles they use to fight other males. Hemideina thoracica, commonly called the Auckland tree wētā, is endemic to New Zealand, and has a wide distribution across the northern two-thirds of the North Island. It is abundant in the central and northern North Island, where it lives in lowland forest or scrub. As a nocturnal, arboreal herbivore, this species uses tree cavities to rest and hide during the day, and emerges at night to feed. It is parapatric with two other Hemideina species in the North Island: H. crassidens and H. trewicki. In warmer areas, H. thoracica is thought to competitively exclude H. crassidens, which is distributed in the lower North Island and the north-west of the South Island.
