Saturday, 9 April 2016

Lichen Case-bearer (Dahlica lichenella)

Following on from the bagworm post below one of the adults emerged overnight and was not the anticipated Narycia duplicella - instead I got the very unexpected and very rarely recorded Lichen Case-bearer (Dahlica lichenella). 
Harry Beaumont seems happy with the identification; there is just one previous Yorkshire record I'm aware of.

As the cases were originally attached to stone I had to cut them off and carefully glue them in the correct orientation to some card when I got them back home. The female - all 2.8mm of her is parthenogenetic which means she emerges with fertile eggs so no need for attracting a mate.

As soon as she emerges she begins laying in side the old case. After a few hours she will die - job done.

She rarely stayed still and flash was used as it was still semi-light outside but some of the pics came out okay.

I  thought she was just laying eggs around the inner edge of the case so I cut it half to have a look when she had finished. Little did I know the case was almost full from back to front!

My identification is largely based on the empty pupal case, in particular the head capsule (see UK Moths for details).

Just a few eggs to rear through now, hopefully I can release plenty back at the site were I found the cases.

I wonder what will pop out of the other case now as my confidence at ID-ing them is none existent.


Colin D said...

A great sequence Charlie very nicely documented

AndyC said...

Winged males of Dahlica lichenella occur in Europe, though in Switzerland populations with both sexes are far fewer than those with only the parthenogenetic wingless female form. Only females have been recorded in Britain; in a few places in southern England, Cheshire, southern Scotland and Perthshire, but the species may have been under-recorded because of identification problems, and males might yet be found.
Fingers crossed for a Male...well done Charlie

AndyC said...

The only other Yorkshire record if ......2013 (CHF): The record on the map is unconfirmed and this species is not on the Yorkshire list. Only wingless females have been recorded in Britain......Nationaal scarce A

AndyC said...

I doubt many people would have ID it from the case..???

brian leecy said...

Wow,Fantastic ,a great find ,well done getting pics too,just shows what can turn up,by putting the time and effort in.

charlie streets said...

Thanks chaps, it was quite a shock to find what was probably my most wanted moth species when I got out of bed.
Harry tells me it was added to the Yorshire list in 2014, he wrote:
"D. lichenella was added to the Yorkshire list last year when a female was found along with cases at a locality where cases suspected of being this moth had been seen in previous years."