49.329 Cydia illutana (Larch Cone Moth)
ws: 12-14mm (BTM), fw: 5.5-6.5 (Sterling & Parsons); Norway spruce (Picea abies), larch (Larix decidua), silver fir (Abies alba); pRDB coniferous woods in S.England
Cydia illutana §3 female
ID: Forewing dark grey-brown; a curved white mid-dorsal mark; white costal strigulae which give rise to leaden metallic striae; ocellus a few blackish spots or dashes bounded proximally and distally by leaden metallic striae. Very similar to C.coniferana, C.cognatana (which only occurs in Scotland) and C.indivisa and likely to need genital determination.
Male genitalia: C. coniferana is readily distinguished by a projection from the anteroventral margin of the valva just proximal to the cucullus; there is a more angular junction between sacculus and neck of the valva in C.cognatana and C.indivisa than in C.illutana. Judging from images at Moth Dissection, the latter 3 species may be distinguished on features of the aedeagus: C.indivisa has a relatively short stout aedaegus with an apical (non-linear) cluster of ~7 unequal thorns; C.illutana has a relatively long narrow aedeagus with an line of cornuti in its apical half (the number of cornuti seems to be very variable ~8–24); C.cognatana also has a long narrow aedeagus but it only has ~2 small thorns in its apical half.
Female genitalia: The species are best distinguished by the arrangement of sclerotisations within the ductus bursae; in C.illutana the colliculum is quadrate and anterior to this is a dentate sclerotised plaque, the ductus seminilis opening between these two sclerotisations.
Male genitalia: C. coniferana is readily distinguished by a projection from the anteroventral margin of the valva just proximal to the cucullus; there is a more angular junction between sacculus and neck of the valva in C.cognatana and C.indivisa than in C.illutana. Judging from images at Moth Dissection, the latter 3 species may be distinguished on features of the aedeagus: C.indivisa has a relatively short stout aedaegus with an apical (non-linear) cluster of ~7 unequal thorns; C.illutana has a relatively long narrow aedeagus with an line of cornuti in its apical half (the number of cornuti seems to be very variable ~8–24); C.cognatana also has a long narrow aedeagus but it only has ~2 small thorns in its apical half.
Female genitalia: The species are best distinguished by the arrangement of sclerotisations within the ductus bursae; in C.illutana the colliculum is quadrate and anterior to this is a dentate sclerotised plaque, the ductus seminilis opening between these two sclerotisations.
§1 Covert Woods, Kent; 09/06/2022; female; fw 6.2mm
§2 Covert Woods, Kent; 09/06/2022; male; fw 5.8mm
§3 Covert Woods, Kent; 09/06/2022; female; fw 6.9mm
§4 Franchises Lodge RSPB, Wiltshire; 25/06/2025; male; fw 4.7mm
All images © Chris Lewis
§2 Covert Woods, Kent; 09/06/2022; male; fw 5.8mm
§3 Covert Woods, Kent; 09/06/2022; female; fw 6.9mm
§4 Franchises Lodge RSPB, Wiltshire; 25/06/2025; male; fw 4.7mm
All images © Chris Lewis
Page published 08/07/2022 (§1-3) | text amended 23/09/2025 | §4 added 05/10/2025
