BIOLOGICAL VARIABILITY IN THE PARTHENOGENETIC GRASSHOPPER WARRAMABA VIRGO (KEY) AND ITS SEXUAL RELATIVES. II. THE WESTERN AUSTRALIAN TAXA.

Abstract

The genus Warramaba is a complex of seven species of morabine grasshoppers (Eumastacidae, Morabine) occurring in southern Australia. This complex includes W. virgo (Key) (formerly Moraba virgo), a parthenogenetic species reproducing by obligate thelytoky, and six sexually reproducing taxa. All but one of the latter are taxonomically undescribed and carry the code designations of the Australian National Insect Collection, i.e., W. picta Key, P196, P169, P152, P125 and P188. The geographic distribution of this complex of species is highly disjunct. Only the parthenogenetic form occurs in eastern Australia but it is widely distributed. About 30 clones are known primarily occurring in the sandy areas of New South Wales and northern Victoria. In this region, virgo is associated with three different species of Acacia which is the primary food plant. Additional clones of virgo were recently discovered in Western Australia with an approximate 1000 mile break in the distribution between the clones in eastern and western Australia. No intermediate clones are known between Broken Hill, N. S.W., and Kalgoorlie, W. A. Further, the six sexually reproducing taxa are confined to Western Australia. In eastern Australia, the parthenogenetic species has been extensively studied cytogenetically (White et al., 1963; White, 1966; White and Webb, 1968; Webb and White, 1975), electrophoretically (Wilks, 1973) and morphometrically (Atchley, 197 7a). However, the western Australian populations of virgo and the sexual species have not been studied although preliminary cytogenetic analyses have been carried out on some of the species (White and Webb, 1966; White et al., 1973). Thus, the purpose of this paper is to extend a series of morphometric analyses on the parthenogenetic grasshopper Warramaba virgo (Key) to the parthenogenetic and sexually reproducing taxa occurring in Western Australia. In the analyses reported here, we are interested in 1 ) ascertaining the relative morphometric divergence and variability in the parthenogenetic species W. virgo and a closely related sexually reproducing species; 2) providing a mechanism to discriminate between virgo and the closely related species P196; and 3) elucidating the phenetic relationships among the various virgo group taxa.