Genetic variation corroborates subspecific delimitation in the Namib fog-basking beetle, Onymacris unguicularis (Haag) (Tenebrionidae, Coleoptera)

By

Lamb, Trip
Pollard, Rachel
Bond, Jason E.

Type

Article

Date of Publication

2013

Original Publication

ZooKeys

Volume

353

Pages

47-60

Subjects

integrative taxonomy , Namib Desert , Onymacris , Subspecies , Tenebrionidae

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.353.6228

 

Abstract

The fog-basking beetle, Onymacris unguicularis (Haag, 1875), is currently listed as a polytypic form comprising two subspecies. A flightless substrate specialist, the beetle is endemic to vegetationless dunes in the Namib, where southern populations constitute the nominate subspecies, O. u. unguicularis, and populations some 300 km to the north compose O. u. schulzeae Penrith, 1984. Their taxonomic descriptions are based on minor differences in pronotal and prosternal shape, and the phylogenetic validity of these subspecies has yet to be ascertained. Here we reassess the polytypic status of O. unguicularis by (1) examining diagnostic phenotypic characters in conjunction with a geometric morphometric analysis, and (2) conducting phylogenetic analysis of mitochondrial DNA sequences. Our results confirm pronotal and prosternal differences, which are complemented by geometric morphometric resolution of the subspecies. Phylogenetic analysis recovered two reciprocally monophyletic lineages that exhibit perfect phylogeographic congruence with phenotypic variation. Our genetic data identify southern and northern populations as distinct lineages, corroborate morphometric data regarding subspecific delimitation, and therefore support the recognition of O. u. unguicularis and O. u. schulzeae as valid taxa under the general lineage concept.