Overview
All Australian Pyrgomorphidae have conical heads and an elevated median process is present on the prosternum of all known species. The fastigium often has the region near the margins raised and uneven and separated from the central portion by lateral sulci which join the median sulcus anteriorly to form a Y. The integument varies from smooth to granular, rugose or tuberculate.
Description
All Australian Pyrgomorphidae have conical heads and an elevated median process is present on the prosternum of all known species. The fastigium often has the region near the margins raised and uneven and separated from the central portion by lateral sulci which join the median sulcus anteriorly to form a Y. The integument varies from smooth to granular, rugose or tuberculate.
Distribution
Only two subfamilies are recognised with only one, the
Pyrgomorphinae
, occurring in Australia. This subfamily has been divided into 31 tribes, 5 of which occur in Australia. The Psednurini, revised by Key (1972) is an endemic tribe with three slender, stem-like genera found around the coastal margins of the continent. They are found on upright, monocotyledonous plants where they reside head upwards. The Atractomorphini comprise only an African genus and
Atractomorpha
which has a widespread distribution in Africa, Asia and Oceania and 3 species in Australia (Key and Kevan 1980). The population cytogenetics of
Atractomorpha
similis
in Australia has been studied by John and King (1983). The Desmopterini contribute two genera which live in leaf litter or on bushes and trees in the northern rainforest.
The most spectacular tribes are the endemic Petasidini and Monistriini (Key 1985). The beautiful Petasidini (
Petasida, Scutillya
) are the most spectacular Australian grasshoppers. Petasidini and Monistrini are usually associated with plants belonging to a restricted group of families that are aromatic. These hosts seem to contribute a distasteful quality to the grasshoppers which is reflected by their aposematic colouration. Petasidini are fully winged. The 4 genera of Monistriini comprise species that are wholly brachypterous or in which a percentage of specimens are fully winged. In both tribes males frequently ride on the backs of the much larger females even when not in copula. The basic chromosome number of both tribes is 2n [male] = 19. Peters (1981) has worked extensively on the cytogenetics of the species.