The forewing measures 17mm. The moth guides say you can differentiate the males by looking at the abdomen, but I think my specimen is a female. Here is an "underneath" photo.
All help/suggestions welcome.
Steve Trigg, Cookham
A Blog for moth recorders in Bucks, Berks and Oxon
Friday, 26 September 2014
Treble-bar or Lesser Treble-bar?
75 moths in the garden trap last night. New for the year were Large Ranunculus, Black Rustic, Grey Pine Carpet and Red-line Quaker, and also this Treble-bar - or is it a Lesser Treble-bar?
The forewing measures 17mm. The moth guides say you can differentiate the males by looking at the abdomen, but I think my specimen is a female. Here is an "underneath" photo.
All help/suggestions welcome.
Steve Trigg, Cookham
The forewing measures 17mm. The moth guides say you can differentiate the males by looking at the abdomen, but I think my specimen is a female. Here is an "underneath" photo.
All help/suggestions welcome.
Steve Trigg, Cookham
Depends which moth guide you use Steve. Skinner says the basal line in Lesser is very sharply angled and round in the Treble-bar, which makes yours a Lesser Treble-bar.
ReplyDeleteHi Steve, using the sharply-angled basal line to determine Lesser Treble-bar works in most cases (including your example) but some are not as clear-cut, which is why the underside view of the abdomen tip is regarded as a more reliable feature. However, that only works in males...
ReplyDeleteThanks Peter and Dave. I can see the difference now in the shape of the basal line.
ReplyDelete