70.098 Dysstroma citrata (Dark Marbled Carpet)
fw: 14-19mm; Jul-Aug in south, Jul-Oct in Scotland; many woody herbaceous plants and trees; common in woodland, heathland and moorland throughout GB. Two subspecies: D.c.citrata - everywhere except northern isles; D.c.pythonissata - Shetland and Orkney.
Synonym: Chloroclysta citrata
Synonym: Chloroclysta citrata
Dysstroma citrata (Dark Marbled Carpet) §1
ID: D.truncata (Common Marbled Carpet) and D.citrata (Dark Marbled Carpet) are both very variable and very similar to each other. They can be distinguished by the following features, which are illustrated in the galleries on the Dysstroma page:
1) Forewing median fascia has a 2-3-pointed projection from its distal margin - the projection is longer and its apices more pointed in D.citrata.
2) Hindwing median cross-line has a pointed ~90 degree angle in D.citrata and a rounded obtuse angle in D.truncata - best seen on underside.
Male Genitalia
3a) Cornutal bundle occupies ~1/2 diameter of aedeagus in D.truncata, ~3/4 in D.citrata.
3b) Peripheral and central cornuti similar in D.truncata; peripheral cornuti much stronger than central cornuti in D.citrata.
Female Genitalia
4a) In D.truncata the sclerotisation of the ductus bursae (DB) is about as long as the diameter of the DB, while in D.citrata the sclerotisation is about twice as long as the diameter of the CB.
4b) The 'frill' of scleorisation in the posterior portion of the corpus bursae has a transverse anterior border in D.truncata, while in D.citrata its anterior border is rounded.
4c) The corpus bursae is broader in D.truncata so that the signum occupies 1/6 to 1/8 of its transverse diameter, while that of D.citrata occupies 1/4 to 1/5.
In dark specimens, a short white flash just distal to the costal end of the forewing median fascia can be a good feature for D.citrata; it may present in D.truncata but is usually much less distinct. In my experience, the cross-lines on the underside of the hindwing are more boldly marked in D.citrata and the antemedian cross-line is never well-developed in D.truncata.
1) Forewing median fascia has a 2-3-pointed projection from its distal margin - the projection is longer and its apices more pointed in D.citrata.
2) Hindwing median cross-line has a pointed ~90 degree angle in D.citrata and a rounded obtuse angle in D.truncata - best seen on underside.
Male Genitalia
3a) Cornutal bundle occupies ~1/2 diameter of aedeagus in D.truncata, ~3/4 in D.citrata.
3b) Peripheral and central cornuti similar in D.truncata; peripheral cornuti much stronger than central cornuti in D.citrata.
Female Genitalia
4a) In D.truncata the sclerotisation of the ductus bursae (DB) is about as long as the diameter of the DB, while in D.citrata the sclerotisation is about twice as long as the diameter of the CB.
4b) The 'frill' of scleorisation in the posterior portion of the corpus bursae has a transverse anterior border in D.truncata, while in D.citrata its anterior border is rounded.
4c) The corpus bursae is broader in D.truncata so that the signum occupies 1/6 to 1/8 of its transverse diameter, while that of D.citrata occupies 1/4 to 1/5.
In dark specimens, a short white flash just distal to the costal end of the forewing median fascia can be a good feature for D.citrata; it may present in D.truncata but is usually much less distinct. In my experience, the cross-lines on the underside of the hindwing are more boldly marked in D.citrata and the antemedian cross-line is never well-developed in D.truncata.
Dissection
Male genitalia
Female genitalia
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§1 Eskdale, Cumbria; 24/08/2007
§2 Patterdale, Cumbria, 28/08/2008 §3 Fersit, Argyll; 29/07/2013; male §4 Skye; 09/08/2013; female; fw 16.5mm §5 Skye; 08/08/2013; female; fw 16.0mm §5 Skye; 07/08/2013; male; fw 14.9mm §6 Skye; 07/08/2013; fw 16.3mm §7 Skye; 08/08/2013; fw 16.2mm All images © Chris Lewis |
§8 Fersit, Argyll; 28/07/92013; female
§9 Dalmunzie (Glenshee), Perthshire; 26/08/2016; male; fw 16.1mm §10 Dalmunzie, Perthshire; 26/08/2016; female; fw 16.6mm §11 Dalmunzie, Perthshire; 26/08/2016; female; fw 17.1mm |
Page published 20/04/2013 (§1-2) | §3-8 added and text revised 27/10/2014 | §9-11 added 13/12/2016
