Key to Elachistidae Group E:
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With the exception of E.consortella, species in this group are more easily separated on external than genital features, (though genital dissection may be necessary to confirm that a specimen is correctly placed in this group).
External characters (based on key in MBGBI3) |
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White mark extending into terminal cilia |
Frons, head and neck tufts white, contrasting with thorax |
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Frons whitish, vertex grey, neck tufts grey, not contrasting with thorax |
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Frons beige, neck tufts mottled |
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White mark extending into apical but not terminal cilia |
White spot in fold between median fascia and base; ciliary line poorly defined |
E.trapeziella |
No white spot in fold between median fascia and base; ciliary line well-defined |
Elachista consortella: This specimen and others of this species seem pale enough to key in Group C (markings both lighter and darker than the ground colour); but the terminal mark is present. I find it hard to be convinced by "frons beige, neck tufts mottled" - and doubt that this species can be reliably identified on external features.
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Elachista cinereopunctella: White mark extending into apical, but not terminal cilia; ciliary line well-defined; no white spot between median fascia and base
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Male genitalia* |
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Uncus lobes claw-like |
Valva with distinct spur arising ventral edge near apex |
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Valva with apical spur vestigial or absent |
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Gnathos paired |
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E.trapeziella / E.cinereopunctella |
*Based on drawings in MBGBI3 and images and descriptions available at Moth Dissection
In MBGBI3 the aedeagus in E.consortella is drawn shorter in relation to the length of the valva than in E.freyerella/stabilella but this does not seem to be a consistent or accurate difference (if I have identified this species correctly). Differences in the shape of the saccus are also drawn in MBGBI3 and are consistent with the descriptions at Moth Dissection, but they are not consistent with the images at Moth Dissection, suggesting that this feature is also unreliable. The drawings in MBGBI3 show a longer spur in E.freyerella than in E.stabilella and the aedeagus mostly straight but bent 1/4 from apex in E.stabilella and more evenly curved in E.freyerella - none of these apparent differences seem to be reliable in separating these species. Moth Dissection comments "the separation of E.freyerella and E.stabilella can be almost impossible via genitalia" and they are certainly easier to distinguish on external features, provided the specimen is not too worn.
E.cinereopunctella and trapeziella should be readily separable by the presence of an additional conspicuous white spot in the basal half of the forewing of E.trapeziella. According to MBGBI3 the male genitalia are best separated on shape of the valva. The difference is illustrated but not described - it appears that the costa may be shorter and more 'blob'-ended at its lateral end in E.cinereopunctella and that the junction between ventral and lateral margins is smoothly rounded in E.cinereopunctella and with a more obvious angulation in E.trapeziella. The image of E.cinereopunctella at Moth Dissection, however, looks more like the MBGBI3 illustration of E.trapeziella and in the drawings in MBGBI3 the most apparent difference is in the shape of the notch in the uncus, which is more widely 'U'-shaped in E.cinereopunctella - so that the uncus of E.cinereopunctella appears somewhat lobed while that of E.trapeziella simply appears notched.
E.cinereopunctella and trapeziella should be readily separable by the presence of an additional conspicuous white spot in the basal half of the forewing of E.trapeziella. According to MBGBI3 the male genitalia are best separated on shape of the valva. The difference is illustrated but not described - it appears that the costa may be shorter and more 'blob'-ended at its lateral end in E.cinereopunctella and that the junction between ventral and lateral margins is smoothly rounded in E.cinereopunctella and with a more obvious angulation in E.trapeziella. The image of E.cinereopunctella at Moth Dissection, however, looks more like the MBGBI3 illustration of E.trapeziella and in the drawings in MBGBI3 the most apparent difference is in the shape of the notch in the uncus, which is more widely 'U'-shaped in E.cinereopunctella - so that the uncus of E.cinereopunctella appears somewhat lobed while that of E.trapeziella simply appears notched.