Withymead Wardens Species Spotlight – Persistent Pseudoscorpions and fearless phoresy

article written by Pete Morton, Withymead Nature Reserve Head Warden

Macro Photography is brilliant, there is a real joy in immersing yourself into the micro landscape of the lawn, hedges or reedbeds and finding yourself surrounded by creatures you never even knew were there. After a few hours hunched or crouched and a stiff back to show for it you may have even got a decent photo or two. On one of my recent forays into the miniature world of Withymead I had stumbled upon a few scenarios that baffled me somewhat. One of which I thought was happenstance but after a second occurrence I thought I would investigate.

In the image above is a Red-legged wasp (Buathra laborator) one of the larger parasitic wasps that can be seen in the UK. If you look closely at its rear leg you can see a small (2mm) Pseudoscorpion (possibly Lamprochernes nodosus) attached at the knee by a claw.

Also known as false scorpions, there are actually 27 know species of pseudoscorpions in the UK, a vastly under studied and under recorded invertebrate, partly due to its size and partly due to the difficulties of identifying the individual characteristics of each.

After watching the pair for a while, the wasp noticed its hitchhiker and a somewhat comical scuffle ensued. After a lot of leg shaking and kicking at the pseudoscorpion, the wasp eventually freed its leg and flew away. A few days later I noticed a click beetle (pictured below) with its own companion which led me to believe this odd behaviour was commonly occurring; so I looked into it. As it happens phoresy is a non-permanent interaction whereby the phoretic individuals attach themselves to a host purely for the purpose of transport. It is a common behaviour among pseudoscorpions and done for a number of reasons. By hitching a ride on a passing invertebrate, they can benefit by reaching new food sources, improving the odds of finding potential mates and assist them in dispersing from where they hatched to reduce the risks of inbreeding in the populous. It’s a bit like grabbing onto a passing helicopter one handed and hoping it’s going past the shops.

Next time you are out and about surveying bees, butterflies, beetles, wasps, flies or anything else for that matter, make sure to keep an eye out for any sneaky pseudoscorpions who may just be hiding in plain sight.