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Identification to genus is usually straightforward by recognition of the yellow-centred dark-bordered labial palps.
"Dichrorampha" means "bicoloured palps". Several species have a distinctive forewing blotch extending obliquely distally from mid-dorsum. Species without a distinctive blotch have an identifiable but obscured blotch in the same position. Females tend to be darker than males of the same species. Most species require genital determination. |
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Identification from external features
A: Species with a distinct median dorsal blotch
A1: Median dorsal blotch white, rectangular and only slightly oblique > D.sequana
A2: Median dorsal blotch pale yellow and curved > D.petiverella
A3: Median dorsal blotch bright orange > D.flavidorsana/alpinana*
A4: Median dorsal blotch dull orange > D.vancouverana
A2: Median dorsal blotch pale yellow and curved > D.petiverella
A3: Median dorsal blotch bright orange > D.flavidorsana/alpinana*
A4: Median dorsal blotch dull orange > D.vancouverana
D.flavidorsana vs D.alpinana to follow when D.flavidorsana material obtained.
According to Sterling & Parsons males can be distinguished by the extent of the forewing costal fold: to ½ in D.alpinana, ⅓ in D.flavidorsana.
There is also a difference in hindwing colouration: grey-brown paler near base in D.alpinana, uniform dark grey-brown in D.flavidorsana - but this distinction must be subtle as they state that females require genital determination.
According to Sterling & Parsons males can be distinguished by the extent of the forewing costal fold: to ½ in D.alpinana, ⅓ in D.flavidorsana.
There is also a difference in hindwing colouration: grey-brown paler near base in D.alpinana, uniform dark grey-brown in D.flavidorsana - but this distinction must be subtle as they state that females require genital determination.
D.sequana
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D.petiverella
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D.alpinana
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D.vancouverana
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B: Species with an obscured median dorsal blotch
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B1: Forewing ground colour dull purplish-brown > D.acuminatana
Two further features distinguish D.acuminatana from the remaining species: 1) The forewing apex is more pointed (acuminate) and the termen more oblique (the termen is at ~60° to the costa c/w ~75° in other species); 2) The median dorsal blotch is whitish and less obscured |
D.acuminatana
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B2: Forewing ground colour brown, grey-brown or olive-brown with at least some irroration with yellow-tipped scales
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B2a: Species that may be identifiable on external features*
D.consortana: Small - fw 4.5-6mm; forewing dark brown; median dorsal blotch white obscured by strigulae; strong white costal strigulae D.simpliciana: Large - fw 6-8mm; forewing grey-brown and noticeably broad with a rounded apex; median dorsal blotch greyish * Sterling & Parsons also state that D.plumbagana, D.sylvicolana and D.alpestrana are identifiable on external features. D.obscuratana has been added to the British list subsequent to their publication and is externally indistinguishable from D.plumbagana. I also regard D.sylvicolana and D.alpestrana as requiring genital determination and county websites have both as verification grade 4. |
D.simpliciana
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B2b: Species requiring genital determination > D.plumbana, D.sedatana, D.aeratana, D.sylvicolana, D.senectana, D.plumbagana, D.obscuratana, D.alpestrana
D.plumbana
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D.sedatana
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D.aeratana
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D.plumbagana
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D.alpestrana
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