Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

FNZ 27 - Antarctoperlinae (Insecta: Plecoptera) - Popular summary

McLellan, ID 1993. Antarctoperlinae (Insecta: Plecoptera). Fauna of New Zealand 27, 70 pages.
( ISSN 0111-5383 (print), ; no. 27. ISBN 0-477-01644-8 (print) ). Published 18 Feb 1993
ZooBank: http://zoobank.org/References/67EDF1AB-4FCB-4ED5-84E1-F1EBF4E1D201

POPULAR SUMMARY

The Antarctoperlinae are a group of stoneflies found only in New Zealand and southern South America. In the classification system of Western science New Zealand has thirty-two species, comprising five in genus Vesicaperla and twenty-seven in Zelandobius. Vesicaperla species are found only in the South Island, but Zelandobius species are represented throughout New Zealand except in the subantarctic islands.

The juvenile forms (nymphs) are markedly different in habitat preference. Nymphs of Zelandobius are found only in streams and rivers,where they feed on detritus and algae. In contrast, Vesicaperla nymphs are terrestrial, living in cool, humid microclimates deep in alpine vegetation. They feed on the outer layers of dead plant material and the hyphae (thread-like strands) and spores (fruiting bodies) of fungi that grow on it.

Nymphs grow and moult several times before finally emerging as soft-bodied adults. These have two pairs of wings in most Zelandobius species, but wings are missing in all but one of the Vesicaperla species. Adult females live for only a few weeks, feeding on plant material and mating before depositing eggs.

Nymphs and adults of Vesicaperla species have developed distinctive dark and pale colour patterns for camouflage in their predominantly tussock grass habitats. When disturbed they resort to behavioural adaptations, common among plant-dwelling insects; such as imitating part of a plant by extending their limbs and antennae and swaying gently.

Zelandobius adults are small to medium-sized insects, rather drab except when the wings are spread to reveal their dark and pale colour pattern. The wings are used for flight, but normally these insects prefer to run in order to escape trouble.

Anglers tie trout flies (artificial lures) to represent stoneflies, but there is no specific pattern assigned to Zelandobius, which is unknown in New Zealand trout fishing literature despite its importance as a food source for native and introduced fishes. Some species, by their presence or absence, are useful indicators of water quality.

Some of the larger stoneflies can be identified with the naked eye, but most identification must be done using a stereoscopic microscope to check features of the wings, body, legs, and genitalia (reproductive structures).