Completely Stuck

Part of my work duties entail setting/checking various pest traps around the premises. By and large it's a fairly quiet affair, the occasional Wood Mouse in a trap or a lost Endrosis sarcitrella in a guest room blunder trap. For me, the most eagerly anticipated part of the trap inspections is when I pop the lids of the five blunder traps that are strategically placed around the kitchen/drystore area. This is where I'm quietly hoping to find a decent exotic pest species. The one I'm really keen to find is Oryzaephilus surinamensis, aka the Saw-toothed Grain Beetle. So far I've come up with an Adistema watsoni, the first record for Scotland and barely found anywhere else in Britain other than in museum blunder traps, and an adult Dermestes peruvianus, found scampering in the drystore area and later handed to me in a cup! During lockdown the hotel was, of course, closed for business. The kitchens were deep-cleaned, the storerooms emptied and my hopes for Oryzaephilus were temporarily put on hold. I did find a Pholcus phalangioides, but otherwise it was quiet throughout.   

But now the hotel is fully open and the kitchens are busy busy once more. There are lorryfuls of food deliveries arriving almost daily, each with the potential of bringing me some lovely pest species to discover, happy days! Today I discovered one. Well, four of one in fact. 

Gotta love an indoor psocid!

I do sometimes find psocids in the sticky traps, but this stood out as something different and I was pretty sure I'd not seen one quite like this before. Scanning the rest of the sticky trap I found three more, all the same species. Psocids tend to shrivel in on themselves after they've been dead a while, these four were all in good shape, so clearly hadn't been stuck in the trap for very long, maybe a couple of days or so. 

Full complement of wings on this individual

I have a copy of the RES Key to Psocoptera (also available as a free download here) and the National Barkfly Recording Scheme has plenty of images and keys too, so it wasn't too tricky to determine my mystery arrivals as belonging to the genus Lepinotus. There are only three species recorded from Britain, two of which are strictly indoor species, the other one occurs outdoors as well as indoors. In short, the key features to check for are a blackish stripe between the eye and antennal socket, postclypeus patterning, the eye colour and whether or not the wings are reticulated. 

This is an awful crop of a wing. Sorry!

It's not particularly evident in this image, but there's a reticulated patterning running across the wing membrane. Look for the small, pale circular spots and suddenly you'll see it (I would take a clearer shot, except the one remaining wing on this specimen has now dropped off and the kitchen is busy at the moment, hence I can't grab another individual from the trap...)

This reticulated pattern is/was quite easy to discern through the microscope, so I'm happy that this is Lepinotus reticulatus. It doesn't have the blackish facial line or greyish-brown eyes of Lepinotus patruelis and it lacks the pronounced reticulate patterning across the postclypeus of Lepinotus inquilinus. 

This is a known pest species, I have informed the bosses and the head chef. The area in question is about to be hit rather hard with some deep-cleaning action and a fogging machine. I'll be monitoring the traps every two or three days rather than weekly (and hoping for one that's still alive and kicking so that I can tick it!)  

The best part of all this is that I know however clean they keep that kitchen, more pests will continue to be brought in by the delivery guys. One day I shall find my Saw-toothed Grain Beetle, and a happy day (for me, at least!) that will be. 

Here's a proper pic of a Lepinotus reticulatus, as found on a sticky trap in Oxford University Museum of Natural History.