Group B)
Species with a pale fascia but no additional pale spots
S.lapponica confusella betulicola sakhalinella luteella glutinosae alnetella microtheriella prunetorum aceris malella centifoliella ulmivora torminalis regiella crataegella hybnerella mespilicola floslactella carpinella tityrella salicis myrtillella obliquella sorbi plagicolella lemniscella
continuella aurella splendidissimella dryadella poterii filipendulae hemargyrella speciosa
E.acetosae
Species with a pale fascia but no additional pale spots
S.lapponica confusella betulicola sakhalinella luteella glutinosae alnetella microtheriella prunetorum aceris malella centifoliella ulmivora torminalis regiella crataegella hybnerella mespilicola floslactella carpinella tityrella salicis myrtillella obliquella sorbi plagicolella lemniscella
continuella aurella splendidissimella dryadella poterii filipendulae hemargyrella speciosa
E.acetosae
Elucidation of this group using the key in MBGBI1 is dependent on determining particularly whether the terminal cilia are abruptly whitish beyond a line of dark-tipped scales and whether the forewing fascia is metallic. I have found that, although in some species these distinctions are obvious, in many species neither of these features can be determined with certainty.
I have found that head and collar colour are more easily determined and each can be fairly readily dichotomised - black vs not black for the head and dark vs pale for the collar. Unfortunately some species are variable or sexually dimorphic for these features so a species may appear at several places in the key.
A combination of features will enable the identification of most specimens in fresh condition; genital confirmation may be required.
I have found that head and collar colour are more easily determined and each can be fairly readily dichotomised - black vs not black for the head and dark vs pale for the collar. Unfortunately some species are variable or sexually dimorphic for these features so a species may appear at several places in the key.
A combination of features will enable the identification of most specimens in fresh condition; genital confirmation may be required.
B1: Head black or blackish, collar pale
B1: a) Terminal cilia contrastingly pale > S.sorbi
S.sorbi is very variable and has a grey-brown to yellow-brown head and collar, which are not necessarily concolorous with each other and that may appear blackish. S.lapponica is usually extremely similar to S.sorbi, but does not include a blackish head in its range of variability.
S.sorbi is very variable and has a grey-brown to yellow-brown head and collar, which are not necessarily concolorous with each other and that may appear blackish. S.lapponica is usually extremely similar to S.sorbi, but does not include a blackish head in its range of variability.
B1: b) Fascia metallic > S.crataegella / S.hybnerella
Both these species show a strong forewing colour contrast golden proximal to the fascia, purple distal to the fascia; these colours are a shade paler in S.hybnerella. Both have androconial scales in the male hindwing. In S.hybnerella these cover the basal ⅔ and extend into the costal and dorsal cilia to ⅕. I do not have a description for those of S.crataegella but they are unlikely to follow this exact pattern. Gen.det may be required.
Both these species show a strong forewing colour contrast golden proximal to the fascia, purple distal to the fascia; these colours are a shade paler in S.hybnerella. Both have androconial scales in the male hindwing. In S.hybnerella these cover the basal ⅔ and extend into the costal and dorsal cilia to ⅕. I do not have a description for those of S.crataegella but they are unlikely to follow this exact pattern. Gen.det may be required.
B1: c) Fascia broadest at dorsum and may be obsolete at costa > S.luteella
B1: d) Fascia entire > S.prunetorum / S.aceris
Males can be distinguished by the presence of androconial scales extending into the dorsal cilia to ¼ in S.prunetorum and their absence in S.aceris. Females will require Gen.det
Males can be distinguished by the presence of androconial scales extending into the dorsal cilia to ¼ in S.prunetorum and their absence in S.aceris. Females will require Gen.det
B2: Head black or blackish, collar dark
B2: a) Terminal cilia contrastingly pale
- Fascia metallic, transverse > S.dryadella
- Fascia metallic, oblique > S.poterii
- Fascia not metallic > S.sorbi
B2: b) Fascia not metallic > S.torminalis (extinct in GB)
B2: d) Terminal cilia concolorous, fascia metallic, antenna not pale-tipped > S.hybnerella / S.mespilicola / ♂S.speciosa / ♂S.lemniscella
Males of all 4 species have androconial scales on the hindwing. In S.speciosa these extend into the costal and dorsal cilia to ½ their length. In S.lemniscella long fuscous scales cover the hindwing and black scales extend into the costal and dorsal cilia to ⅔. ♂S.lemniscella has a black vertex and ochreous frons. In S.hybnerella and S.mespicolella androconial scales cover the basal 2/3 of the hindwing and extend into the costal and dorsal cilia to ⅕ their length. These two may be separable in both sexes on forewing ground colours: in S.hybnerella pale golden proximal to the fascia, purple distal to the fascia; in S.mespicolella copper-brown proximal to fascia, blackish-brown distal to the fascia. (♀S.speciosa and ♀S.lemniscella have a reddish head)
Males of all 4 species have androconial scales on the hindwing. In S.speciosa these extend into the costal and dorsal cilia to ½ their length. In S.lemniscella long fuscous scales cover the hindwing and black scales extend into the costal and dorsal cilia to ⅔. ♂S.lemniscella has a black vertex and ochreous frons. In S.hybnerella and S.mespicolella androconial scales cover the basal 2/3 of the hindwing and extend into the costal and dorsal cilia to ⅕ their length. These two may be separable in both sexes on forewing ground colours: in S.hybnerella pale golden proximal to the fascia, purple distal to the fascia; in S.mespicolella copper-brown proximal to fascia, blackish-brown distal to the fascia. (♀S.speciosa and ♀S.lemniscella have a reddish head)
B3: Head red or reddish, collar pale
B3: a) Terminal cilia contrastingly pale
The fascia is dull in all species in this group with the exception of S.carpinella in which it is faintly shining
The fascia is dull in all species in this group with the exception of S.carpinella in which it is faintly shining
B3: a) 1: Fascia distinctly oblique > S.tityrella / S.salicis / S.obliquella / S.myrtilella
♂S.tityrella has a subbasal patch of dark brown scales on the forewing underside and a brush of pale hair-like scales at the base of the hindwing underside. Both sexes of S.tityrella have the antenna with a pale grey basal ⅔ and contrastingly dark grey apical ⅓. The remaining 3 species are very similar externally and usually require Gen.det., but S.salicis may be identifiable by having the fascia constricted in midwing.
♂S.tityrella has a subbasal patch of dark brown scales on the forewing underside and a brush of pale hair-like scales at the base of the hindwing underside. Both sexes of S.tityrella have the antenna with a pale grey basal ⅔ and contrastingly dark grey apical ⅓. The remaining 3 species are very similar externally and usually require Gen.det., but S.salicis may be identifiable by having the fascia constricted in midwing.
B3: a) 2: Fascia ~transverse > S.lapponica / S.confusella / S.malella / S.floslactella / S.carpinella / S.zelleriella / S.sorbi
- Fascia indistinct > S.zelleriella. This species usually lacks a fascia and is keyed in group C, but this is variable and when a fascia is present it will key here.
- Dull pale ochreous basal portion of the forewing distinctly contrasting with the dark apical area > S.floslactella, ♀S.zelleriella. ♀S.floslactella has long yellow anal tufts and ♀S.zelleriella have a long pointed ovipositor with pale grey anal tufts. Forewing contrast is much less marked in the remaining species in this group and in some ♂S.zelleriella
- Pale antennae (darker grey towards tip), fascia broad > S.carpinella
- Long pale grey anal tufts > ♀S.sorbi
- S.lapponica, S.confusella, S.malella and ♂S.sorbi are externally very similar and require Gen.det
B3: b) Terminal cilia ~concolorous with forewing apex
B3: b) 2: Fascia metallic, ~transverse > ♀S.lemniscella, S.hybnerella, S.continuella
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B3: b) 3: Fascia not metallic > S.sakhalinella, S.luteella, S.glutinosae, S.centifoliella, S.betulicola*
- Fascia broadest at dorsum > S.sakhalinella, S.luteella. These two may be distinguishable by the darker fuscous proximal forewing of S.sakhalinella but gen.det needed.
- Fascia of even width > S.glutinosae, S.centifoliella, S.betulicola. Gen.det needed
B4: Head red or reddish, collar dark
B4: a) Terminal cilia contrastingly pale
B4: a) 1: Fascia metallic, distinctly oblique > S.poterii
B4: a) 2: Fascia metallic, ~transverse > S.aurella, S.splendidissimella
These two are very similar. Usually S.aurella has a yellowish head and S.splendidissimella has a blackish head but the colour range is described in Nepticuloidea.info as ochreous-orange to dark brown for S.aurella and ochreous to dark brown for S.splendidissimella, so head colour, while suggestive, is not diagnostic. S.aurella has a brown thorax and forewing base while in S.splendidissimella these areas are greenish-gold. Gen.det likely to be required |
B4: a) 3: Fascia not metallic > S.hemargyrella, S.sorbi
- Head white > S.hemargyrella Head colour in S.hemargyrella is white to pale ochreous in ♂, white in ♀. Head colour in S.sorbi is grey-brown to yellow-brown in ♂ and pale ochreous in ♀. So once sexed head colour should distinguish these two.
- Androconial scales in hindwing > ♂S.hemargyrella. (Absent in ♂S.sorbi)
- Long pale grey anal tufts > ♀S.sorbi. (Absent in ♀S.hemargyrella)
B4: b) Terminal cilia ~concolorous with forewing apex
B4: b) 1: Fascia metallic > S.alnetella, S.regiella, S.filipendulae, S.hybnerella, S.speciosa
Female S.hybnerella and S.speciosa can be identified on forewing colour contrast and fascia shape
Separation of female S.alnetella, S.regiella and S.filipendulae probably require Gen.det; but the latter would be separable on antennal length if it is similar to the male or at least longer than ½ forewing length (In most Stigmella species the female antenna is shorter than the male)
- Antenna ¾ length of forewing > ♂S.filipendulae. ~½ forewing length in the other species in this group except S.alnetella in which it is slightly longer than ½ forewing length in the ♂ (not described for ♀S.filipendulae)
- Scape shining yellowish white edged silvery to metallic grey > ♂S.alnetella
- Marked colour contrast proximal and distal to fascia > S.hybnerella, S.speciosa. In S.hybnerella the colours are bright golden and bright purple; in S.speciosa greenish gold shading to dark purplish brown and purplish black. Little colour contrast in S.alnetella, S.regiella, S.filipendulae
- Fascia broadest at dorsum > S.speciosa
- Fascia broad, brassy and indistinct > S.regiella
- Androconial scales in hindwing > ♂S.regiella, ♂S.hybnerella, ♂S.speciosa. In S.regiella extending into dorsal cilia to ⅓; in S.hybnerella covering the basal ⅔ of the hindwing and extending into the costal and dorsal cilia to ⅕; in S.speciosa extending into costal and dorsal cilia to ½
Female S.hybnerella and S.speciosa can be identified on forewing colour contrast and fascia shape
Separation of female S.alnetella, S.regiella and S.filipendulae probably require Gen.det; but the latter would be separable on antennal length if it is similar to the male or at least longer than ½ forewing length (In most Stigmella species the female antenna is shorter than the male)
B4: b) 2: Fascia not metallic > S.betulicola*, S.plagicolella
- Antenna ⅗ forewing length > ♂S.plagicolella. ½forewing length in ♀S.plagicolella, not described for S.betulicola but ½ forewing length in all other species in the betulicola group (apart from S.alnetella in which it is slightly longer than ½ forewing length)
*Placement of S.betulicola is problematic. At the time of writing no description is available at Nepticuloidea.info. MBGBI1 describes the head as pale to ochreous yellow, often mixed fuscous in ♂ and ferruginous in ♀ and the collar as leaden fuscous in both sexes. However, some web images labelled S.betulicola show a white collar - notably the excellent image at Moth Dissection