70.110 Epirrita filigrammaria (Small Autumnal Moth)
fw: 14-18mm; Aug-Sep; heather (Calluna vulgaris), bilberry (Vaccinium myrtillus), sallows (Salix spp); common in upland areas of Scotland, N.England & N.Wales
Epirrita filigrammaria (Small Autumnal Moth) §1 male
ID: Very similar to the other three Epirrita species; averages smaller but with overlap through most of the size range. Usually distinguishable from the other three species by flight season as none of them fly before the end of September.
Male genitalia: Octavals short, widely spaced and inclined medially. Valvae with an angular prominence on the ventral border but without a distinct dentate projection (which is present in E.dilutata and E.christyi). Dissection group suggests that E.autumnata and E.filigrammaria cannot be separated on male genital features. Pierce states that the octavals are smaller with a shallower excavation between them in E.autumnata and that the number of hairs on the christae, ~19 in E.autumnata, ~7 in E.filigrammaria, provides a clear distinction.
Female genitalia: There is probably no reliable means of separating female Epirrita species, though Pierce suggests that the signa of E.autumnata are distinctly smaller than those of the other 3 species.
Male genitalia: Octavals short, widely spaced and inclined medially. Valvae with an angular prominence on the ventral border but without a distinct dentate projection (which is present in E.dilutata and E.christyi). Dissection group suggests that E.autumnata and E.filigrammaria cannot be separated on male genital features. Pierce states that the octavals are smaller with a shallower excavation between them in E.autumnata and that the number of hairs on the christae, ~19 in E.autumnata, ~7 in E.filigrammaria, provides a clear distinction.
Female genitalia: There is probably no reliable means of separating female Epirrita species, though Pierce suggests that the signa of E.autumnata are distinctly smaller than those of the other 3 species.
Dissection
Male genitalia
Female genitalia
§1 Dornie, Ross-shire; 12/09/2014; male; fw 16.8mm
§2 Dornie, Ross-shire; 12/09/2014; male; fw 16.4mm
§3 Dalmunzie (Glenshee), Perthshire; 28/08/2016; male; fw 14.2mm; to light
§4 Dalmunzie (Glenshee), Perthshire; 29/08/2016; female; fw 14.0mm; to light
All images © Chris Lewis
§2 Dornie, Ross-shire; 12/09/2014; male; fw 16.4mm
§3 Dalmunzie (Glenshee), Perthshire; 28/08/2016; male; fw 14.2mm; to light
§4 Dalmunzie (Glenshee), Perthshire; 29/08/2016; female; fw 14.0mm; to light
All images © Chris Lewis
Page published 09/12/2014 (§1-2) | §3-4 added 04/01/2017
