INTRASPECIFIC KARYOTYPE VARIATION IS NOT CONCORDANT WITH ALLOZYME VARIATION IN THE AUCKLAND TREE WETA OF NEW-ZEALAND, HEMIDEINA-THORACICA (ORTHOPTERA, STENOPELMATIDAE)

Nine karyotpes are described within a single species of common New Zea land tree weta. Their diploid numbers range from 11 to 25. The distrib ution of the karyotypes suggests that each had a single origin except the 17-karyotype which was the most common karyotype and had a disjunc t distribution. The overall level of allozyme diversity observed is si milar to that seen within many widespread taxa. The distribution of al lozyme alleles did not coincide with the distribution of karyotypes wi thin this species and the Neighbour-Joining tree was not concordant wi th the chromosome based sub-divisions of the species. Thus, no evidenc e was found to suggest that chromosomal differentiation has been actin g as a barrier to the flow of alleles within H. thoracica. The lack of concordance of genetic markers is thought to result from rapid chromo some radiation and reticulate evolution. Northland peninsula of North Island, New Zealand is a region of high chromosomal and allozymic dive rsity in H. thoracica. This may have resulted from geographic isolatio n during the Pliocene when Northland formed an archipelago of many sma ll low-lying islands. (C) 1997 The Linnean Society of London.