70.062 Epirrhoe rivata (Wood Carpet)
fw: 14-16mm; Jun-Jul; bedstraws (Galium spp); local in England & Wales
Epirrhoe rivata (Wood Carpet) §2 male
ID: Similar to X.alternata (Common Carpet) and probably under-recorded because of this similarity. Larger (fw of X.alternata 13-14mm); white postmedian fascia broader (white band >½ width of median fascia at costa in X.rivata, <½ width in X.alternata); no grey line through white postmedian fascia of hindwing (present and usually well-marked in X.alternata). The grey line through the white postmedian band on the forewing seems to be more variable but is usually weakly marked in X.rivata and may be largely absent particularly in its dorsal half.
Male genitalia: Indistinguishable from X.alternata.
Female genitalia: A comparative image is shown at Moth Dissection but this does not make it entirely clear what the diagnostic differences are. Judging from these images and comparison of my own preparations I propose the following. In both species there is a sclerotisation that extends from the left side of the ductus bursae into the corpus bursae. In X.rivata the portion of this sclerotisation in the ductus bursae is shorter and narrower than the portion in the corpus bursae. In X.alertnata the portion in the ductus bursae is longer than the portion in the corpus bursae and about the same diameter.
Male genitalia: Indistinguishable from X.alternata.
Female genitalia: A comparative image is shown at Moth Dissection but this does not make it entirely clear what the diagnostic differences are. Judging from these images and comparison of my own preparations I propose the following. In both species there is a sclerotisation that extends from the left side of the ductus bursae into the corpus bursae. In X.rivata the portion of this sclerotisation in the ductus bursae is shorter and narrower than the portion in the corpus bursae. In X.alertnata the portion in the ductus bursae is longer than the portion in the corpus bursae and about the same diameter.
§1 Cyffdy Farm, Gwynedd; 21/06/2010
§2 Heydon, Cambridgeshire; 12/06/2025; male; fw 15.0mm
§3 Heydon, Cambridgeshire; 12/06/2025; female; fw 14.4mm
All images © Chris Lewis
§2 Heydon, Cambridgeshire; 12/06/2025; male; fw 15.0mm
§3 Heydon, Cambridgeshire; 12/06/2025; female; fw 14.4mm
All images © Chris Lewis
Page published 10/04/2013 (§1) | §2&3 added and text amended 01/10/2025
