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.