Notes on pitfall trapping on Headlong Peak, Mount Aspiring National Park

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Abstract
A series of 12 pitfall traps baited with ethylene glycol smelling of carrion, was installed from forest in the Dart Valley (900 m) to the limit of continuous vegetation on Headlong Peak (1830 m). The traps were installed to sample the ground surface fauna of major habitats in the area in February 1980. Trap catches, and weights of 0.1 g or more, are tabulated for Orthoptera, Blattodea, most Coleoptera, and Calliphoridae (Diptera). Other Arthropoda caught are discussed briefly. There is a major discontinuity at the timberline between the faunas of high altitude forest and alpine vegetation. Another faunal discontinuity occurs at about 1800 m, just below the limit of continuous vegetation, and associated with a substantial change in composition of the vegetation. The weight of insects caught in any alpine trap exceeded the weight of insects caught in any forest trap by at least 10 times. Large orthopterous alpine herbivores represented by far the greatest biomass. The burrowing weta Zealandosandrus maculifrons (Stenopelmatidae) and the alpine grasshopper Sigaus australis (Acrididae) were most important. A giant weta Deinacrida sp. nov. (Stenopelmatidae) were frequent above 1800 m, although only one was caught in a trap. The most numerous predators were Agonum sp. 1 (Carabidae) and Creophilus oculatus (Staphylinidae). The former was the only species caught in all pitfall traps. All Orthoptera and Blattodea caught in alpine traps are exclusively alpine, but some of the Coleoptera extend upwards from high altitude forest, and others also occur in lowland grasslands.