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Showing posts with label staph. Show all posts
Showing posts with label staph. Show all posts

Monday, January 7, 2019

Not sweating the small stuff


I picked up these two beetles off an Autumn bracket fungus on a lunch time walk. Both are pretty small at around 2mm each.

The first is pretty distinctive when seen well. A very thin, pointy neck and bulging elytra point to Autalia, one of the easier of the nightmarish aleocharine staphs. There are four species in this genus and they invariably turn up in dung, decaying material and on fungi.

Of the four species only 2 are multi-colored like this - impressa and longicornis. The differences are subtle and best gauged against reference material. So this will have to go down as Autalia sp. until I can compare with others. 

There's a useful overview of the genus here.

This size of beetle is also at the limits of my dissection skills, which may go someway in explaining why I failed to find any genitalia when I took a look inside!


The other beetle from the same fungus is another staph and is equally small. I think this is in the genus Proteinus and if so is possibly ovalis but I'm not sure. So for now will have to join the others in my box of beetles labelled as 'No f***ing idea."


Monday, March 13, 2017

Struggling with staphs

So I've been trying to ID a bunch of staphs that I have left over from last season and I must admit to having mixed success. They certainly aren't easy. Well at least for me!

Take this one for instance


I think this a Xantholinus sp. At 8mm and with microstructure (but not too strong microstructure) it keys out as Xantholinus gallicus - but there aren't many records on NBN and I guess I'll need to wait and compare to some known specimens in a collection somewhere.

Someone somewhere reading this will be asking what the $%£@ is microstructure?

So glad you asked.....

You can make it out at about 40x magnification but it's the very fine structure (in this case) on the pronotum

Microstructure of Xantholinus gallicus (credit http://www.micropics.org.uk/) 
Pretty nifty when you see it well.