Bagworm? (Cumbria, UK) (1 Viewer)

Hello

This larva was found on a fencepost in woodland near Carlisle earlier today. Three others were found nearby but not photographed.

It was roughly triangular in cross-section, and the case was measured at about 6mm in length.

Presumably it's a bagworm (Psychidae) of some sort? If so, is it possible to id the species from these photos?

Thanks

Paul

Having done a bit more work on this, it looks like it's one of the Lichen Case-bearer bagworms - perhaps Dahlica inconspicuella? Probably not possible to reliably id from these photos though...

According to Micro Moths of G.B. & Ireland, by Sterling and Parsons, British Wildlife Publishing 2012, for D. inconspicuella the larval case is: ''5-6 mm, slender, triangular in cross-section, covered with fine granular material. It is usually whitish grey or greenish grey, sometimes with lichen fragments attached. The case is usually found on tree trunks and fences, and under scree, shingle and rubble on the ground,and is sometimes numerous. Similar cases: Bankesia conspurcatella, which is pale brownish and has minute woody fragments attached; D. lichenella, from which it is practically indistinguishable. Cases may also be confused with D.triquetella,a rare species recorded from a few well-scattered locations....''
In the book none of these is mapped for the Carlisle area though.
Your local moth recorder might well be able to help so, from a Butterfly Conservation list of county moth recorders, dated June 2017:

VC69 & VC70 Westmorland with North Lancashire & Cumberland
All species
Record Collator: Gary Hedges
Email: [email protected]
Tel: 07719 519225

Best of luck with IDing this,

Thomas

Thanks for that, Thomas.

I submitted my sighting - along with photos - to the Cumbria branch of BC and it's been provisionally listed as Dahlica inconspicuella. However, I don't think it's yet been assessed by the County Moth Recorder, and so it may not withstand scrutiny!

There are currently no county records (at least according the NBN Atlas) for this bagworm - or in fact for any of the other similar-looking species you listed. I'd be surprised if they're all locally scarce though, and I imagine that the reason there aren't any records is due to id issues.

In fact I found another bagworm a few days later near Brampton, in a very similar habitat. The larva wasn't visible at the time, and so I collected the case and took some shots later in the day at home (see attached). This also had a triangular cross-section and was measured at about 7mm in length and so it's perhaps a better fit for Dahlica lichenella.

This has also been submitted to BC for consideration, but I'm not very optimistic about it. I believe it's possible to determine the species from the pupal sack, but I'm not intending to hold onto it for that long!

Regards

Paul

Hi Paul,

Really interesting stuff so I hope you do get the IDs sorted out in the end.

Cheers,

Thomas