Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

FNZ 2 - Osoriinae (Insecta: Coleoptera: Staphylinidae) - Distribution

McColl, HP 1982. Osoriinae (Insecta: Coleoptera: Staphylinidae). Fauna of New Zealand 2, 96 pages.
( ISSN 0111-5383 (print), ; no. 02. ISBN 0-477-06688-7 (print) ). Published 23 Dec 1982


Generally, the known distribution of New Zealand osoriines reflects that of indigenous forest, and in areas where little of the original vegetation remains (e.g., parts of Northland, around Auckland, Hawkes Bay, south Taranaki and the southern West Coast of the North Island, and east of the Main Divide in the South Island) very little information regarding distribution could be obtained. Some species persist when native forests are cleared and planted with exotic species (e.g., McColl 1974). Certain species appear to be adapting to modification of their forest habitat, and are maintaining large populations. Others appear to be present in such small numbers, and/or in such scattered localities, that I can only surmise that these are relict populations which will ultimately disappear.

One species described by Broun from south Auckland appears to be extinct already. However, since exact habitat requirements for every species are not known, some apparently rare species may occur in adequate numbers in small microhabitats within the forest floor.

Sympatry is the rule rather than the exception, and is greatest at Mount Messenger (TK), where seven species occur. The continued separation of sympatric species is assured by the form of the copulatory piece and the bursa copulatrix, and these characters are considered to be of the greatest specific significance.

Full collecting data for all material examined are recorded in McColl (1981). These data are briefly summarised here: a paragraph each is devoted to substrate types and associated plant species; altitudinal range; months in which specimens have been taken; and sympatry with other Osoriinae. Sympatry is expressed at two levels - co-occurrence of species in a particular sample, and occurrence together at a particular locality (but not, so far, in the same litter sample).

It must be stressed that collecting data reflect the foraging habits and seasonality of entomologists first and foremost. Only intensive collecting and careful identification can lead us towards a true picture of the natural limits of species as inconspicuous as the Osoriinae. As an aid to visualisation of known range, distribution maps are given for all species, regardless of the richness or paucity of the known material.

It is hoped that collectors will respond actively to the challenge of the many gaps revealed by this study. New data, preferably supported by voucher specimens, will be welcomed by the author and by the Systematics Section of DSIR's Entomology Division.

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