Taxonomic revision of the Afro-Arabian anthidiine bee Pseudoanthidium ochrognathum sensu lato (Apoidea: Anthidiini), based on morphological and genetic data

Abstract

The megachilid bee Pseudoanthidium ochrognathum (Alfken, 1933) is known from coastal and inland sand dunes of both North Africa and the Arabian Peninsula. While we found some differences in the colour pattern and punctation of the integument between these two populations, the DNA sequence of the mitochondrial cytochrome c oxidase I (COI) gene was found to be largely identical; the difference in the base sequence (Tamura 3-parameter) was less than 1% and therefore did not support species-level distinctiveness. After examining the holotypes of Anthidium arenosum Warncke, 1982, described from Iran, and P. micronitens Pasteels, 1981, described from Saudi Arabia, both taxa are proposed as junior synonyms (syn. n.) of P. ochrognathum. On the other hand, Anthidium beaumonti Benoist, 1950 (stat. res.), which was considered as a synonym of P. ochrognathum, is revealed to be different based on morphological and morphometric parameters, and its status as a valid species is resurrected. This taxon includes “A. ochrognathum var. obscuratum Benoist”, which is considered herein to be a colour morph. Additionally, P. rubellulum Pasteels, 1969 (stat. res.) is treated as a valid, closely related species occurring in a limited range in southern Israel, and is therefore removed from synonymy with P. ochrognathum. The species-level differences in colouration and punctation between P. rubellulum and P. ochrognathum are confirmed by a genetic distance of 6.0–6.7% in the COI gene. It is suggested to refer to the three species P. ochrognathum, P. beaumonti and P. rubellulum as the P. ochrognathum species group.