35.049 Bryotropha similis (Obscure Moss-moth)
ws: 10.5-13.5mm; Jun-Aug; uncommon throughout Britain

ID: External Features - Labial palp S3 longer than S2, S2 with conspicuous furrowed brush; ws 9-13mm; 1st discal stigma distal to plical stigma; fw ground colour blackish; plical stigma distal border without a cluster of pale yellowish scales; fw without pale irroration; costal and tornal patches yellowish if present. B.umbrosella is similar - it has white costal and tornal patches and cluster beyond plical stigma
B.affinis shows pale irroration of the fw and conspicuous pale scales beyond the plical stigma, but may appear otherwise very similar to B.similis.
Male Genitalia: Aedeagus with whip-like apex; sacculus present; (base of gnathos and surface of vinculum without microtrichia); gnathos slender - at least 3x as long as wide, markedly thickened at middle then gradually narrowing to a sharp point.
The key in MBGBI4.2 also refers to the number of spikes on the thornshield (up to 100 in B.similis) but this feature seems to require higher powered microscopy than is available to me - as does the presence or absence of microtrichia at base of gnathos. The 4 species that show microtrichia are easily excluded as 2 of them (galbanella and boreella) lack a furrowed brush on labial palp S2 and the the other two (terrella and desertella) have a very distinctive gnathos.
Female Genitalia: Signum consisting of a plate with strong spines on the corners; (microtrichia on S8 needle-shaped); lamella post-vaginalis without lobes; signum elongate, twice as long as wide and longer than apophyses anteriores.
B.affinis shows pale irroration of the fw and conspicuous pale scales beyond the plical stigma, but may appear otherwise very similar to B.similis.
Male Genitalia: Aedeagus with whip-like apex; sacculus present; (base of gnathos and surface of vinculum without microtrichia); gnathos slender - at least 3x as long as wide, markedly thickened at middle then gradually narrowing to a sharp point.
The key in MBGBI4.2 also refers to the number of spikes on the thornshield (up to 100 in B.similis) but this feature seems to require higher powered microscopy than is available to me - as does the presence or absence of microtrichia at base of gnathos. The 4 species that show microtrichia are easily excluded as 2 of them (galbanella and boreella) lack a furrowed brush on labial palp S2 and the the other two (terrella and desertella) have a very distinctive gnathos.
Female Genitalia: Signum consisting of a plate with strong spines on the corners; (microtrichia on S8 needle-shaped); lamella post-vaginalis without lobes; signum elongate, twice as long as wide and longer than apophyses anteriores.
§1 Cyffdy Farm, Gwynedd; 24/06/2010; male; fw 5.3mm
§2 Bampton Grange, Cumbria; 17/06/2017; male; fw 5.3mm
§3 Bampton Grange, Cumbria; 09/07/2017; male; fw 5.6mm
§4 ??; 2020; male
§5 Bampton Grange, Cumbria; 10/06/2023
§6 Bampton Grange, Cumbria; 10/06/2023
§7 Camas-luinie, West Ross & Cromarty, 25/07/2023; female; fw 5.4mm
All images © Chris Lewis
§2 Bampton Grange, Cumbria; 17/06/2017; male; fw 5.3mm
§3 Bampton Grange, Cumbria; 09/07/2017; male; fw 5.6mm
§4 ??; 2020; male
§5 Bampton Grange, Cumbria; 10/06/2023
§6 Bampton Grange, Cumbria; 10/06/2023
§7 Camas-luinie, West Ross & Cromarty, 25/07/2023; female; fw 5.4mm
All images © Chris Lewis
Page published 19/12/2011 (§1) | §2 added 15/03/2018 | §3 added 12/04/2018 | §4 added 2020 | §5&6 added 07/12/2023 |
§7 added 10/12/2023
§7 added 10/12/2023