Studies in Australian Gryllacrididae: Taxonomy, biology, ecology and cytology

Abstract

This study utilises new taxonomic characters to define the Australian Gryllacrididae. Notes on biology, ecology and behaviour are presented. The chromosome complements of ten species are reported and illustrated. Nullanullia maitlia Rentz. gen. et sp. nov. was shown to be facultatively parthenogenetic in the laboratory. Kew taxonomic characters include the structure of the mandible and maxilla, the femoroabdominal stidulatory apparatus, the structure of the fastigium of the vertex, the punctation and colour of the frons, the size. shape and the medium and textured ocelli, and the detailed structure of male and female genitalia including sculpture of the ovipositor.

Arrolla Rentz, gen. nov. is proposed to include A. rotamah (type species), A. lawrencei, A. platystyla, A. weiri, A. tibialis. A. turramurrae, A. lewisi, A. longicauda spp. nov.; A. fuscifrons (Ander) is transferred from Pareremus Ander to Arrolla Rentz. gen. nov. Apotrechus Brunner is defined and includes A. unicolor Brunner (type species), and A. illawarra Rentz. sp. nov. Kinemania Rentz, gen. nov. is described to include a single Tasmanian species. K. ambulans (Erichson) hitherto included in Apotrechus. Wirritina Rentz, gen. Nov. is proposed to include W. brevipes (Ander) (type species) formerly placed in Apotrechus and W. naumanni Rentz, sp. nov. Cooraboorama Rentz. gen. nov. is described for a single species, C. canberrae Rentz. sp. nov. Notes on several well-knoun species of Pareremus are presented with illustrations and redescriptions of types. 'Pareremus' atrofrons (Tepper), based on immatures, is probably misplaced in Pareremus. Penthoplophora Tepper. originally described as a stenopelmatid. is synonymised with Ametrus Brunner: no stenopelmatids are known from central Australia. The monotypic genera Ametrosomus Tepper and Apteronomus Tepper are redescribed and their type species described and illustrated. Moorscra Rentz, gen. nov. is described to include three fully-winged species: M. canobolas (type species), M. curragundi Rentz, spp. nov. Mooracra sp. 1 is illustrated but not described. Paragryllacris Brunner is redefined and its type species. Gryllacris combusta Gerstaecker, is described and illustrated. Chauliogryllacris Rentz. gen. nov. is proposed to include seven species, two of which are well-known — C. lobata (Brunner) and C. exserta Brunner. The genus also includes C. grahami (type species) and C. nungeena Rentz spp. nov.; other species are noted but not described. Nunkeria Rentz, gen. nov. is described to include two species, N. maitila, (type species) and N. feehani spp. nov. Nullanullia Rentz gen. nov. includes two species, N. maitlia (type species) and N. kotla spp. nov. Hyalogryllacris Karny is discussed and its large number of species (25) noted. H. hyalina (Brunner) (type species) is described and its role as a host for the sphecid wasp, Sphex vestitus. is noted. Hyalogryllacis sp. 9 is illustrated but not described. This paper reports the first cytological information for the Gryllacrididae from Australia. Chromosome numbers of 10 species indicate three clusters of species. These are not taxonomically relevant. One cluster with four species showed relatively high counts 2n = 26 female, 25 male; another cluster with three species showed a reduced diploid number apparently as a result of fusions; a third cluster contained three species with numbers ranging from 2n = 14 female to 2n = 10 female; in this group the number of large metacentrics has been reduced to either two or one. It seems that karyotype evolution in the gryllacridids has evolved in at least three ways: (1) Robertsonian fusion. (2) alterations in the amount and location of heterochromatin, and (3) structural rearrangements other than fusions.