Description
Systematics Various authors both in Britain and on the Continent have referred to this widely distributed European species by the name Megachile argentata (Fabricius). However, Hurd (1967) has demonstrated that this was based on a misidentification, as true M. argentata only occurs in north Africa, and is not the same species as that occurring throughout much of Europe. I concur with Hurd in accepting M. leachella Curtis (1828) as the first available name for the European species. Unfortunately Curtis described the species very briefly: “The smallest species of the genus, and may prove to be the M. papaveris Latr. Specimens are preserved in the British Museum”. This brief description is valid under articles 12 and 13 of the International Code of Zoological Nomenclature. Doubt may be raised concerning the homogeneity of the type series because of his inclusion of M. papaveris (Latreille) in the description, as this species name is now applied to a well known Palaearctic Hoplitis. Hoplitis papaveris is a bee not known to occur with certainty in Britain, and thus Curtis may not have been familiar with it. Curtis’s (1828) account shows that he was well able to distinguish the genera Megachile and Hoplitis (i.e. Osmia, which at that time included all Hoplitis species), and therefore it seems unlikely that he would have committed an error of this magnitude. Later revisers (e.g. Shuckard, 1866) unanimously accepted Curtis’ verdict, and Shuckard at least would almost certainly have had access to Curtis’ type material in the British Museum. Unfortunately the type series cannot now be traced.