Scirtes pinjarraensis Watts, 2004

Watts, Chris H. S., Cooper, Steven J. B. & Saint, Kathleen M., 2017, Review of Australian Scirtes Illiger, Ora Clark and Exochomoscirtes Pic (Coleoptera: Scirtidae) including descriptions of new species, new groups and a multi-gene molecular phylogeny of Australian and non-Australian species, Zootaxa 4347 (3), pp. 511-532 : 526

Scirtes pinjarraensis Watts, 2004

= Scirtes pygmaeus Watts, 2004 , syn. nov.

Notes. Cooper et al. (2014), using sequence data, suggested that Scirtes pinjarraensis and S. pygmaeus Watts were probably conspecific. Examination of further specimens of both taxa confirms this. Watts (2004) separated the two taxa by the presence of a distinctly bent tip to the trigonium in S. pygmaeus which was absent in S. pinjarraensis . Examination of additional specimens of both taxa shows that this bent tip is actually a distinct spine projecting at right angles to the trigonium and surrounded by a number of much smaller spines ( Fig. 22 ). Dissection of more paratypes of S. pinjarraensis showed that a number had identical structures and that the absence of a spine was caused by it being broken off, probably during dissection. We consider, on both morphological and sequence grounds, that S, pinjarraensis and S. pygmaeus are conspecific. Therefore, S. pygmaeus on page preference becomes a junior synonym of S. pinjarraensis .

This terminal structure on the trigonium is unique within Australian Scirtes and readily identifies the species, which is often the commonest scirtid in swamps in southwest Australia. Other than by the male genitalia, the species is recognized from other species in southwest Australia by its small size, dark testaceous colour with pale antennal base and pale sides to the pronotum.

In size, colour and male genitalia S. pinjarraensis resembles S. lynnae , but differs from this species in the hooked left parameroid, presence of a small right parameroid and spines at the apex of the trigonium.

Sequence data place it close to S. helmsi and S. brisbanensis ( Fig. 1 ).

Figures

FIGURE 1. Phylogenetic tree of Australian Scirtes, Ora, Exochomoscirtes and some related Asian species, based on Bayesian inference (BI) analysis of concatenated sequence data of COI, EF 1 - a and TOP 1. A tree with identical topology was obtained using ML analyses of the same data set and a concatenated dataset comprising only COI and TOP 1. Numbers on branches give posterior probabilities (left) from BI analyses and bootstrap proportions (right) as a percentage of 500 pseudoreplicates from a ML analysis.

FIGURES 17 – 22. Tegmen and penis of: 17) Scirtes auratus; 18) S. serratus; 19) S. interstinctus; 20) S. lynnae; 21) S. albamaculatus. 22) Penis of S. pinjarraensis.