For all the degradation in this land

 

The garden's offerings of field mushrooms have started to go over now and I spent half an hour yesterday on my hands and knees looking at some of the more manky ones!

There were a fair number of beetles in amongst the fast forming mush, mostly Proteinus brachypterus. One rather globular individual caught my eye and I was pleased on looking down the microscope to clap eyes on my first Onthophilus striatus.

This 2mm histerid is reasonably common in decaying matter across the south of England becoming more sporadic the further north you get. The above image doesn't do it justice but it's a remarkably intricately sculptured beetle.

There were also a few of this Omalium staph. 

These are not an easy group. But this one is the commonest of the genus. It has rather bulging sides to the head and the impressions in front of the ocelli are large and rounded. This means it should be O. rivulare, and luckily for my keying skills the aedeagus agrees with me!

 

It was good to compare to another Omalium that I had been looking at the day before. This one had come to light back in May and is O. caesum.

Its elytra are relatively shorter and the head somewhat longer. It's first and second antennal segments are darker too and this is one of the features that separates it from the closely related O. rugatum.

  

The aedeagus is a fair bit different from rivulare but the differences between caesum and rugatum appear to be slight.

The best images I can find are at the french site, galerie-insecte.org. You can see O. rugatum and O. caesum the lateral view (from the side) seems to be the best way to distinguish the two, but as I haven't knowingly seen rugatum yet I'll have to get back to you if that actually is the case.

The post title comes from a new discovery, for me at least, the rather wonderful Lebanon Hanover.