49.187 Endothenia oblongana (Downland Marble)
ws: 11-15mm (BTM), fw 5-7mm (Sterling & Parsons); Jun-Jul; common knapweed (Centaurea nigra); local in England & Wales
Endothenia oblongana §1 male
ID: Similar to E.genitianaeana which averages larger (fw 6-9mm) and E.marginana (fw 5-7mm). Males of E.marginana are distinct in having a white hindwing. Minor differences from its congeners in forewing pattern are mentioned in BTM and Clifton&Wheeler: the white subterminal fascia is relatively narrow and the terminal area relatively heavily suffused, resulting in less white than dark distal to the median fascia.
Male genitalia: In E.gentianaeana and E.oblongana the aedeagus is without cornuti, in E.marginana the aedeagus has (~9 short stout) cornuti. In all three species there is a spined ventral extension of the sacculus; in E.gentianaeana and E.oblongana this extension is at ~1/3 of the valva so that the valva beyond the extension is relatively long, in E.marginana this extension is close to 1/2 of the valva so that the valva beyond the extension appears relatively short. In E.oblongana the uncus is rounded; in E.gentianaeana the uncus is also rounded but its posterior margin is indented (two of the images labelled as E.gentianaeana at Moth Dissection show a rounded uncus without indentation); in E.marginana the uncus is flattened. MBGBI5.2 also illustrates a small difference between the 3 species in the exact form of the saccular extension, but I have yet to be convinced that this is useful in distinguishing E.gentianaeana from E.oblongana.
Female genitalia: In E.gentianaeana and E.oblongana the posterior margin of the ostium is pointed; in E.marginana it is rounded. (As far as I have been able to establish): In E.gentianaeana the posterior margin of the ostium is pointed but not notched and the sclerotisation in the posterior part of the ductus bursae is separate from and weaker than the ostial sclerotisation. in E.oblongana the posterior margin of the ostium is pointed and notched at the point, and the sclerotisation in the posterior part of the ductus bursae is continuous with and about as strong as the ostial sclerotisation.
Male genitalia: In E.gentianaeana and E.oblongana the aedeagus is without cornuti, in E.marginana the aedeagus has (~9 short stout) cornuti. In all three species there is a spined ventral extension of the sacculus; in E.gentianaeana and E.oblongana this extension is at ~1/3 of the valva so that the valva beyond the extension is relatively long, in E.marginana this extension is close to 1/2 of the valva so that the valva beyond the extension appears relatively short. In E.oblongana the uncus is rounded; in E.gentianaeana the uncus is also rounded but its posterior margin is indented (two of the images labelled as E.gentianaeana at Moth Dissection show a rounded uncus without indentation); in E.marginana the uncus is flattened. MBGBI5.2 also illustrates a small difference between the 3 species in the exact form of the saccular extension, but I have yet to be convinced that this is useful in distinguishing E.gentianaeana from E.oblongana.
Female genitalia: In E.gentianaeana and E.oblongana the posterior margin of the ostium is pointed; in E.marginana it is rounded. (As far as I have been able to establish): In E.gentianaeana the posterior margin of the ostium is pointed but not notched and the sclerotisation in the posterior part of the ductus bursae is separate from and weaker than the ostial sclerotisation. in E.oblongana the posterior margin of the ostium is pointed and notched at the point, and the sclerotisation in the posterior part of the ductus bursae is continuous with and about as strong as the ostial sclerotisation.
§1 St Mary's, Isles of Scilly; 02/08/2022; male; fw 5.9mm (specimen provided by Mick Scott)
§2 St Mary's, Isles of Scilly; 14/08/2022; male; fw 6.3mm (specimen provided by Mick Scott)
§3 Kishorn, Ross & Cromarty; 21/06/2022; female; fw 6.3mm; netted by day
All images © Chris Lewis
§2 St Mary's, Isles of Scilly; 14/08/2022; male; fw 6.3mm (specimen provided by Mick Scott)
§3 Kishorn, Ross & Cromarty; 21/06/2022; female; fw 6.3mm; netted by day
All images © Chris Lewis
Page published 13/09/2022 (§1&2) | §3 added 11/12/2022
