The common red-winged dung beetle is two species
When we were out collecting dung beetles from bison dung at the Plains Conservation Center a week ago, by far the most numerous beetles were the red "Europeans". The red-winged Aphodius dung beetle, believed to be an invasive from Europe and having been brought over by the first settlers on their dirty ships, is one of the most abundant dung beetles in North America. It was known as Aphodius fimetarius Linnaeus, 1758, described by the father of scientific naming in his Systema Naturae over 250 years ago. Because it is so common and widespread on both sides of the Atlantic, few people have bothered studying it in detail. Now it turned out to be two – two distinct species with quite some difference in the mitochondrial DNA, different distributions, different chromosomes, and even different phenology in Colorado. Although they are difficult to differentiate in the field, under the microscope most of them can be identified by external morphological characters alone. The differences in the chromosomes were discovered fourteen years ago by Christine Wilson, at the time a PhD student with Robert Angus at Royal Holloway, University of London. Not many people "believed" her then. In the following decade, several authors found potential differentiating characters. We now published a comprehensive analysis of different character systems based on over 4400 specimens (4401 to be exact) in Systematic Entomology, clarifying the species status of both sibling taxa, namely Aphodius fimetarius and A. pedellus (De Geer, 1774), once and for all. Here is the abstract. Ask me for a pdf of the paper. Discoveries can indeed be made amongst the most common and apparently well-known bugs.
(Photo by Chris Grinter; Aphodius pedellus, Germany, Saxony, Hundshübel, 31 July 1983, leg. FT Krell; DMNS ZE.5662)
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