A Tenuous Case

I made use of a couple of free hours this afternoon. First off, I headed to Swithland Reservoir in glorious sunshine. I'd only just got out of the car when I noticed a few ducks close to the dam by the overflow, including two of my favourite species beginning with G ....

Gadwalls were preening and having a drink in between bouts of courtship ...

No such luck for this lone drake Goldeneye.

After grabbing a few snaps, I set about my main purpose. Staring at walls. It didn't take long to find the expected Psychidae.

Luffia lapidella f. ferchaultella

Dahlica sp. - found a good number of cases in a slightly different section of the boundary wall to where I usually look. All looked to be D. lichenella, no potential D. triquetrella.

I noticed one moving about, surprisingly. They overwinter as full-fed larvae and should be pupating by now. When I got my hand lens out to have a good look at this one I noticed something else very close by .....

Bristly Millipede - never ceases to amaze me how these are invisible when you are actually looking for them.

Whilst I was enjoying these wall-dwellers, they were not what I was actually looking for. News came through during the week that Keith Tailby and Mark Hammond had found putative silk-tube cases of Infurcitinea argentimaculella. The photos seemed compelling, if a little inconspicuous. They'd been found at Ulverscroft and along the Swithland Res walls, but I was seeing nothing. After a quick call to Keith, I decided to head over to Ulverscoft and try there.

I was soon looking at a much more promising habitat, with the dry stone wall covered in a powdery blue-grey lichen (Lepraria sp.). If you think looking for larval cases of Psychidae is tenuous, you ought to try this .....

This is likely to overwinter as a small larva, but should be starting to become active again in spring, so it seems likely that bigger cases are old and vacated. I've collected a couple to have a look at, but definitely this is one to make an effort to return to in a couple of months. With lichens generally doing better now, and with eg the spread of lichen-feeding footmen spp., seems likely that this has also done well in the last decade or so and could well be wide-spread. After all, even when it's on your radar (which it wasn't) it is not exactly jumping out at you!

Just before getting back in the car, I had a quick look at the outer wall and quickly found more Psychids.

Narycia duplicella