The Orthopteroid insects of Norfolk Island, with descriptions and records of some related species from Lord Howe Island, South Pacific

Abstract

The Orthoptera and Blattodea of Norfolk I. and adjacent Philip I. are discussed as a result of two recent expeditions sponsored by the Australian National Parks and Wildlife Service and CSIRO. The origins, affinities, taxonomy and ecology of species is presented. Relevant notes and descriptions of related species from Lord Howe I. are also included. Twenty species of Orthoptera are known from Norfolk I. and Philip I. Crickets are the dominant group (10 species) probably because they oviposit in plant tissue which is readily dispersed overseas. Ten orthopteran species have their origins in mainland Australia. Three are definitely of New Caledonian origin; the remainder are from south-east Asia. Fifty-five per cent of species are endemic and 72% of these are flightless. Introduced wild olive on Philip I. is considered important in pro-viding litter and cover in which a number of endemic species survive on this otherwise ecologically devastated landscape. Seven species are described as new: Phisis tardipes, sp. nov.; Austrosalomona personafrons, gen. et sp. nov.; A. zentae (Lord Howe), gen. et sp. nov.; Caedicia gracilis, sp. nov.; C. araucariae, sp. nov.; C. noctivaga, sp. nov.; C. mesochides (Lord Howe), sp. nov.

Eight species of Blattodea (cockroaches) are recorded from the islands. Only three are considered native, the others have been introduced through commerce. Evidence is presented suggesting that Periplaneta americana (L.), present on Norfolk but not on Philip, has outcompeted and eliminated a native cricket on Norfolk; the cricket is present and common in similar habitats on Philip I. No new species are described.