My plan is to have a short blog at the end of each week, covering one species in a little more detail. I’ll try to pick particularly interesting or enigmatic species, that not everybody may have heard of.
So the species this week is: Platyarthrus hoffmannseggii! Or if you’d prefer, the Ant Woodlouse. This small, white Woodlouse grows up to 4-5mm in length, and is easily recognised but its colour, short antennae, rounded body, and by occurring exclusively in Ant nests. I’ve found it most frequently under slabs, logs and stones in the nests of the Yellow Meadow Ant (Lasius flavus), and the Black Garden Ant (Lasius niger), though it has been recorded from the nests of the ‘Red Ants’ (Myrmica spp.). It is fairly frequent throughout the South of the UK, but probably under-recorded. It feeds on Ant droppings, mildew and general detritus within the nest. I’m never quite sure why the Ants don’t prey on their cohabitants, as it’s made clear by observing the nests that the Ants are aware of the Woodlice being present. Any suggestions are welcome on that!
The Ant Woodlouse is also blind, so taps its antennae rapidly on the ground in front of it in order to feel where it’s going. Because of the way it bumbles about, and its substantial name, I think that Platyarthrus hoffmannseggii is the most characterful of all the British Woodlice. (Please feel free to prove me wrong!).
The photo below shows a few of them wondering around in a Lasius flavus nest under a slab in my garden.
For some better photos (without having to wait for me to set up my macro lens!) follow this link to the excellent British Myriapod and Isopod Group (BMIG) website:
And for a nice distribution map:
So if you haven’t seen Platyarthrus hoffmannseggii already, go out and find it before it gets too cold!