Cytological studies of Antipodean Teleogryllus species and their hybrids (Orthoptera: Gryllidae)

Abstract

Testes from nymphs of the last three instars of 10 populations of Australasian "black" field crickets, Teleogryllus commodus and T. oceanicus, and some of their hybrids, were examined to determine the number and morphology of their chromosomes. All populations gave counts of 2n = 27 in the male. The karyotypes of different populations and the hybrids are presented in tabular form with illustrations and idiograms. Some anomalies in chromosome numbers and structure were found, notably the occurrence of polyploid cells in the hybrids of T. commodus populations and in the interspecific hybrids.Chromosomal polymorphism was found to be common, except in some non-continental populations. Lampbrush-like chromosomes were found in metaphase 1 of interspecific hybrids and in the intraspecific hybrids of T. oceanicus. Achromatic gaps occur in T. oceanicus and in a population of T. commodus from Victoria, Australia.