The blackburni/murchisona species complex in Australian Pseudotetracha (Coleoptera: Carabidae: Cicindelinae: Megacephalini): evaluating molecular and karyological evidence

Our phylogenetic analysis of three endemic species of the Australian tiger beetle genus Pseudotetracha (Fleutiaux, 1864) from South Australia used sequences of two fragments of the mitochondrial genes 16S rRNA and cytochrome oxidase III. A matrix for each gene and two combined matrices were constructed. We compared these three riparian species, together with data from nine taxa of this genus available in GenBank, using parsimony and Bayesian methods. These molecular results are in agreement with the phylogenetic hypothesis for the blackburni/murchisona species complex previously proposed based on morphology, whereas other recent molecular analyses have questioned the existence of this species complex. In all of our analyses, samples of P. blackburni divided into two statistically supported clades, one of which is more closely related to P. mendacia and P. pulchra than to the other P. blackburni clade. This suggests the existence of a cryptic new species. Additionally, we analysed chromosomes of the second metaphase cells of members of the two clades. The observations showed different karyotypes as blackburni‐1 has two types of second meiotic metaphase cells with 11 and 12 chromosomes, whereas in blackburni‐2, all cells have 12 chromosomes, adding evidence for the putative existence of two species.