Synanthropes

A synanthrope is a species that lives near, and benefits from, an association with human beings and the somewhat artificial habitats that people create around themselves. The association can vary. Species from warmer climates may make the move northwards aided by the warmer environment offered by our heated homes and buildings. Others have made use of the concentrations of stored food products that we create in various places.

I've recorded a few species of beetle in the house and garden that fall in to this category over the last few years. Blaps mucronota is the most spectacular of these and seems to live under the kitchen floorboards. I've also had several species to light on those warm summer nights.

Yesterday I had a quick sieve of the compost heap and found two species that fall neatly into this category. Firstly was Alphitophagus bifasciatus a species of tenebrioid that also has the name Two-banded Fungus Beetle. It's now found across the globe and I first recorded it to light last year.

The second species was completely new for me and had me going round the houses for quite a while.

Looking at it it was obviously a cryptophagid, and I was pretty sure it was in the genus Cryptophagus. But no, the pronotal shape didn't fit, no median tooth and the upper projection wasn't right. So must be a Micrambe. Again, no for similar reasons. I ended up just flicking through the very useful family pages at UKBeetles for inspiration.

And there it was, a member of Silvanidae, Ahasverus advena, aka the Foreign Grain Beetle. This used to be quite scarce but has expanded its range over recent years with records as far north as Cheshire and Yorkshire. Another one of those few species doing very well out of us humans.

You are a force you are a constant source...

 ... of new beetles.

Last night's warm temperatures had me putting out two light traps in the garden, one MV and one actinic. The latter often delivers the better diversity of beetles especially in the first hour or two of darkness.

However, it is rubbish at holding the beetles as there are too many small escape routes for smaller stuff to leave by. The trick is to hang around the trap and regularly check the sides and surrounding area and pooter up the most interesting bits for further scrutiny.

I quickly found some Bradycellus verbasci, Trechus quadristriatus, Anotylus rugosus as well a couple of Cryptophagus that will need further inspection before I probably cry and give up.

Then two of these beetles appeared...

My first thought was that it was a Mycetophagus species, but the size of 2.5mm ruled that out. I then used the old rule that if you can't get a beetle to family then go and check the Tenebrionidae! 

So this is Alphitophagus bifasciatus aka the 'two-banded fungus (or flour) beetle. It's an established introduction and there doesn't appear to be a huge number of records (33 on NBN and 2 on iRecord). It is usually found in mouldy grain and flour and occasionally in rotting vegetation and on fungi.

New for me and new for the garden. The light traps continue to deliver 😀