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NEPTICULIDAE | Nepticulinae | Nepticulini
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04.007 Stigmella luteella (Short-barred Dot)
ws: 4-5mm (MBGBI1), 4.7-5.2mm (Nepticuloidea.info); May-Jul; leaf-mine Aug-Nov; birch (Betula spp); common in England Wales and S.Scotland
Stigmella luteella §1 male
ID: Forewing with a pale fascia and no additional pale markings; head blackish, collar pale; fascia broadest at dorsum and may be obsolete at costa (terminal cilia not contrastingly pale, fascia not metallic). Note that the head colour of this species is variable from pale yellow to dark fuscous.
Male genitalia: The group 04.005-009 (S.betulicola, S.sakhalinella, S.luteella, S.glutinosae, S.alnetella) all have a small aedeagus with an apical pair of crenulate cornuti and a central irregular band cornutus - they probably do differ in the detail of these cornuti, but this detail is difficult to see and may show intraspecific variation. Of these species only S.luteella regularly has a dark head. S.alnetella is the only one of the group with a dark collar.
S.betulicola has an uncus with a transverse posterior margin without lateral projections, and the vinculum has a moderate emargination with slightly pointed anterolateral projections (and its forewing fascia is in a more distal position).
S.glutinosae has a very shallowly concave posterior margin to the uncus with very small projections at the lateral angles, and a deep emargination of the vinculum between broadly rounded anterolateral projections.
S.sakhalinella, S.luteella and S.alnetella all have the uncus with the posterior margin concave between distinct posterolateral projections; in all the anterolateral projections of the vinculum are broad. In S.sakhalina the emargination of the vinculum is shallow, in S.luteella it is deep U-shaped and in S.alnetella it is moderate V-shaped.
Female genitalia:
Male genitalia: The group 04.005-009 (S.betulicola, S.sakhalinella, S.luteella, S.glutinosae, S.alnetella) all have a small aedeagus with an apical pair of crenulate cornuti and a central irregular band cornutus - they probably do differ in the detail of these cornuti, but this detail is difficult to see and may show intraspecific variation. Of these species only S.luteella regularly has a dark head. S.alnetella is the only one of the group with a dark collar.
S.betulicola has an uncus with a transverse posterior margin without lateral projections, and the vinculum has a moderate emargination with slightly pointed anterolateral projections (and its forewing fascia is in a more distal position).
S.glutinosae has a very shallowly concave posterior margin to the uncus with very small projections at the lateral angles, and a deep emargination of the vinculum between broadly rounded anterolateral projections.
S.sakhalinella, S.luteella and S.alnetella all have the uncus with the posterior margin concave between distinct posterolateral projections; in all the anterolateral projections of the vinculum are broad. In S.sakhalina the emargination of the vinculum is shallow, in S.luteella it is deep U-shaped and in S.alnetella it is moderate V-shaped.
Female genitalia:
§1 Cliburn Moss, Cumbria; 11/06/2023; male; fw 2.6mm; to light
All images © Chris Lewis
All images © Chris Lewis
Page published 06/07/2023 (§1)
