This shiny, iridescent dung beetle is relatively common during the summer in the hills of Galicia, NW Spain. It is a type of dor beetle (Family: Geotrupidae) and appears to specialise on horse dung, at least that is where they can be found in the hills of Galicia. Cleaning up after the Galician ponies!
The beetle is a very shiny, metallic green colour, with a distinct reddish hue, on the upper or dorsal surface; underneath they are shiny blue. These beetles are so shiny that you can sometimes see yourself reflected in their pronotum (back) or elytae (wing cases), as shown below. I have however, occasionally come across much duller coloured ones, which have presumably just emerged from underground, or feeding on dung. They also have lovely, shiny blue legs!
These dung beetles are a variety, or subspecies of Trypocopris (=Geotrupes) pyrenaeus, probably T. pyrenaeus var. coruscans which only occur in central or western parts ofm the Iberian peninsula, as well as Galicia in the north-west. (1) A picture of a beetle – T. pyrenaeus var. coruscans – which looks very similar to the ones shown here, can be seen on this Spanish site of Galician arthropods (1). What characterises this species (T. pyrenaeus) are: i) distinct striae on the wing-cases; and ii) and a distinct marginal ridge, or flange, around the entire base of the pronotum. The reddish sheen is also diagnostic. So these beetles seem to fit the description for this species, although it is difficult to go entirely on photographs alone. Some magnificent pictures of Geotrupid beetles can be seen on the site called World Wide Beetles (2).
These dung beetles are good parents take care of their young. Both males and females are earth-boring, and burrow down into the soil to construct brood chambers, where they rear their larvae. They provision the chambers with dung for the developing larvae to feed on during a long development period, up to 8 months to a year I believe. If you pick them up and handle them, as below, they eventually get fed up and fly off!
I am a retired entomologist with a background in quarantine pests and invasive invertebrates. I studied zoology at Imperial College (University of London) and did a PhD on the population dynamics of a cereal aphid (Metopolophium dirhodum) in the UK. I spent 5 years with the British Antarctic Survey studing cold hardiness of Antarctic invertebates and 17 years with the Food and Environment Research Agency. My main interests now are natural history, photography, painting and bird watching.