28.013 Crassa tinctella (Plain Bark Moth)
ws: 14-16mm (MBGBI4.1), fw 6-8mm (Sterling & Parsons) ; May-Jun; lichens on willows (Salix spp); NS-B in ancient woodland in southern half of England and N.Wales
Crassa tinctella §1 male
ID: Very similar to Crassa unitella, which flies Jun-Aug. C.unitella has a head down resting posture while C.tinctella has a horizontal posture. In C.unitella the head and palps are contrasting bright ochreous yellow vs much less contrasting ochreous orange in C.unitella - though this difference may be less apparent with wear.
Male genitalia: In C.unitella the aedeagus has a strongly dentate sclerotisation near the apex of the tunica and a weak linear cornutus; in C.tinctella the apex of the tunica is very weakly dentate and has a moderate linear cornutus.
Female genitalia: In C.unitella the introitus is funnel-shaped and the bursa lacks a signum; in C.tinctella the introitus is more strongly sclerotised and more cyclindrical and the bursa contains a moderate plaque-like signum
Male genitalia: In C.unitella the aedeagus has a strongly dentate sclerotisation near the apex of the tunica and a weak linear cornutus; in C.tinctella the apex of the tunica is very weakly dentate and has a moderate linear cornutus.
Female genitalia: In C.unitella the introitus is funnel-shaped and the bursa lacks a signum; in C.tinctella the introitus is more strongly sclerotised and more cyclindrical and the bursa contains a moderate plaque-like signum
§1 Orlestone Forest, Kent; 18/05/2020; male; fw 7.0mm
§2 Orlestone Forest, Kent; 24/06/2020; female; fw 6.0mm
All images © Chris Lewis
§2 Orlestone Forest, Kent; 24/06/2020; female; fw 6.0mm
All images © Chris Lewis
Page published 28/05/2020 (§1) | §2 added 27/01/2021
