49.229 Epinotia caprana (Large Willow Roller)
ws: 16-22mm (BTM, MBGBI5.2), fw 8.0-10.5mm (Sterling & Parsons); Jul-Oct; willows (Salix spp), bog-myrtle (Myrica gale); local on moor, fen, heath, moss and gravel throughout GB
Synonym: Astatia semifuscana (Pierce & Metcalfe)
Synonym: Astatia semifuscana (Pierce & Metcalfe)
ID: Polymorphic and variable with intergradation between forms.
Similar to E.maculana/sordidana/brunnichana/solandriana and may require genital dissection for confident identification.
Form caprana: forewing divided longitudinally into purplish-brown or ferruginous-brown costal 2/3 and whitish dorsal 1/3; the dorsal 1/3 may be more or less heavily suffused grey or ochreous; the dividing line is indented near 1/2 and near tornus.
Form brunneofasciana: chestnut basal patch, median and subterminal fasciae; remainder of forewing suffused grey
Form griseana: forewing suffused grey; basal patch, median and subterminal fasciae grey, indistinct
Form fuscomaculana: forewing greyish-fuscous with more pronounced fuscous median fascia and distal margin to basal patch
Form fuscofasciana: forewing ferruginous with fuscous median fascia and distal margin to basal patch
Form piceana: forewing ferruginous to chestnut, unicolorous or with some paler areas
Form fuscana: melanic
Form sciurana: costal and dorsal broadly purplish-brown; central longitudinal ferruginous streak, expanding to occupy terminal area.
Male genitalia: Differences between the Epinotia species occur in the shape of the valva, but these are quite subtle. All the confusion species mentioned above are shown at Moth Dissection and illustrated in MBGBI5.2. They have an elongate valva with a ventral emargination and groups of short spines on the ventral margin of the sacculus and along the ventral margin of the cucullus. In E.caprana the margin of the sacculus is evenly rounded; the ventral emargination is a moderate even curve and there is a further shallow emargination of the cucullus. In E.maculana both the sacculus and the ventral emargination are angular. In E.sordidana the ventral emargination is very shallow. In E.brunnichana and E.solandriana the ventral emargination is deeper giving a more obviously defined cucullus
Female genitalia: Epinotia species have a sclerotised ostium, a ring of sclerotisation in the ductus bursae at or near the origin of the ductus seminilis; and 2 elongate rounded-ended signa in the bursa copulatrix. All the confusion species mentioned above are shown at Moth Dissection and illustrated in MBGBI5.2. E.caprana has medium length, stout signa of fairly even width, with the left signum slightly larger than the right. The shape of the ostium is presumably of some importance as there are close-up images of it at Moth Dissection - these show a horseshoe of sclerotisation on the anteroventral and lateral margins and a broader more diffuse sclerotisation of the posterodorsal margin - (it is not clear to me that this pattern is shown in the illustration is MBGBI5.2). (It should also be noted that the ostium in nature is set at an angle to the anterior-posterior plane of the image - so the photographic appearance will depend on the degree of flattening achieved in preparation to some extent). E.maculana has the ductus bursae about the same length as the bursa copulatrix while in E.caprana the ductus bursae is distinctly shorter than the bursa copulatrix. Other possible differences are that in E.caprana the posterodorsal expansion of the ostial margin broadens so that it extends lateral to the lateral margins of the ostium, while in E.maculana there is no lateral extension; and in E.maculana the signa appear more or less exactly the same size. E.sordidana may be best distinguished by having the ductus bursae longer than the bursa copulatrix. E.brunnichana and E.solandriana both have long narrow signa (length > 2x width). E.brunnichana may be further distinguished by having the left signum attached to the bursa copulatrix at a much lower level than the right signum.
Similar to E.maculana/sordidana/brunnichana/solandriana and may require genital dissection for confident identification.
Form caprana: forewing divided longitudinally into purplish-brown or ferruginous-brown costal 2/3 and whitish dorsal 1/3; the dorsal 1/3 may be more or less heavily suffused grey or ochreous; the dividing line is indented near 1/2 and near tornus.
Form brunneofasciana: chestnut basal patch, median and subterminal fasciae; remainder of forewing suffused grey
Form griseana: forewing suffused grey; basal patch, median and subterminal fasciae grey, indistinct
Form fuscomaculana: forewing greyish-fuscous with more pronounced fuscous median fascia and distal margin to basal patch
Form fuscofasciana: forewing ferruginous with fuscous median fascia and distal margin to basal patch
Form piceana: forewing ferruginous to chestnut, unicolorous or with some paler areas
Form fuscana: melanic
Form sciurana: costal and dorsal broadly purplish-brown; central longitudinal ferruginous streak, expanding to occupy terminal area.
Male genitalia: Differences between the Epinotia species occur in the shape of the valva, but these are quite subtle. All the confusion species mentioned above are shown at Moth Dissection and illustrated in MBGBI5.2. They have an elongate valva with a ventral emargination and groups of short spines on the ventral margin of the sacculus and along the ventral margin of the cucullus. In E.caprana the margin of the sacculus is evenly rounded; the ventral emargination is a moderate even curve and there is a further shallow emargination of the cucullus. In E.maculana both the sacculus and the ventral emargination are angular. In E.sordidana the ventral emargination is very shallow. In E.brunnichana and E.solandriana the ventral emargination is deeper giving a more obviously defined cucullus
Female genitalia: Epinotia species have a sclerotised ostium, a ring of sclerotisation in the ductus bursae at or near the origin of the ductus seminilis; and 2 elongate rounded-ended signa in the bursa copulatrix. All the confusion species mentioned above are shown at Moth Dissection and illustrated in MBGBI5.2. E.caprana has medium length, stout signa of fairly even width, with the left signum slightly larger than the right. The shape of the ostium is presumably of some importance as there are close-up images of it at Moth Dissection - these show a horseshoe of sclerotisation on the anteroventral and lateral margins and a broader more diffuse sclerotisation of the posterodorsal margin - (it is not clear to me that this pattern is shown in the illustration is MBGBI5.2). (It should also be noted that the ostium in nature is set at an angle to the anterior-posterior plane of the image - so the photographic appearance will depend on the degree of flattening achieved in preparation to some extent). E.maculana has the ductus bursae about the same length as the bursa copulatrix while in E.caprana the ductus bursae is distinctly shorter than the bursa copulatrix. Other possible differences are that in E.caprana the posterodorsal expansion of the ostial margin broadens so that it extends lateral to the lateral margins of the ostium, while in E.maculana there is no lateral extension; and in E.maculana the signa appear more or less exactly the same size. E.sordidana may be best distinguished by having the ductus bursae longer than the bursa copulatrix. E.brunnichana and E.solandriana both have long narrow signa (length > 2x width). E.brunnichana may be further distinguished by having the left signum attached to the bursa copulatrix at a much lower level than the right signum.
§1 Dungeness, Kent; 25/07/2017; male; fw 8.4mm; to light; form sciurana
§2 Dungeness, Kent; 26/07/2017; female; fw 10.0mm; to light; form?
§3 Dungeness, Kent; 25/07/2017; male; fw 8.9mm; to light; form piceana
§4 Dungeness, Kent; 25/07/2017; male;to light; form caprana
§5 St Marys, Isles of Scilly; ??/??/20??; male; fw 8.2mm
§6 Cockayne's Wood, Essex; 09/10/2023; male; fw 9.6mm; specimen supplied by Gavin Price
§7 Cromdale, Moray; 27/08/2024; male; fw 9.2mm
All images © Chris Lewis
§2 Dungeness, Kent; 26/07/2017; female; fw 10.0mm; to light; form?
§3 Dungeness, Kent; 25/07/2017; male; fw 8.9mm; to light; form piceana
§4 Dungeness, Kent; 25/07/2017; male;to light; form caprana
§5 St Marys, Isles of Scilly; ??/??/20??; male; fw 8.2mm
§6 Cockayne's Wood, Essex; 09/10/2023; male; fw 9.6mm; specimen supplied by Gavin Price
§7 Cromdale, Moray; 27/08/2024; male; fw 9.2mm
All images © Chris Lewis
Page published 01/09/2017 (§1-4) | §5 added 27/12/2021 | §6 added 01/12/2023 | §7 added 18/10/2024