LASIOCAMPIDAE: Malacosomatinae: Malacosomatini

66.004 Malacosoma (Trichodia) castrensis (Ground Lackey)

fw: m13-16mm, f17-21mm; Jul-Aug; herbaceous saltmarsh plants; NS-A saltmarsh and coastal shingle in SE.England
Picture
Malacosoma castrensis (Ground Lackey) §2 male
ID: colour varies from pale yellow to reddish-brown; two cross-lines on forewing with no white central spot; fringes chequered. 
Very similar to M.neustria (Lackey); the following features can be used to distinguish these species.
  1. Habitat: M.castrensis is confined to saltmarsh and coastal shingle in SE.England. 
  2. First cross-line: In M.neustria more or less parallel with second cross-line; in M.castrensis the first cross-line is kinked in its costal half so that the median fascia has a corresponding narrowing (this being much less obvious in the female), and the dorsal portion of the first cross-line curves towards the wing base. 
  3. Forewing fringes: In M.neustria chequered brown and yellowish, in M.castrensis chequered brown and buff showing less contrast.
  4. Hindwing colour: In M.neustria the either concolorous with the forewing or paler; in M.castrensis either concolorous or darker. 
  5. Hindwing fringes: In M.neustria chequered with the darker colour darker than the wing; in M.castrensis chequered with the darker colour concolorous with the wing. 
  • Variation
  • Dissection
  • Male genitalia
  • Female genitalia
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§1 Foulness, Essex; 11/07/2010; female; fw 16.1mm
§2 Foulness, Essex; 01/08/2010; male; fw 13.5mm
§3 Foulness, Essex; 21/07/2018; female; fw 21.0mm
§4 Foulness, Essex; 14/08/2021; female; fw 20.4mm
§5 Foulness, Essex; 14/08/2021; female; fw 20.2mm
​§6 Foulness, Essex; 12/08/2023; female; fw 19.5mm
All images © Chris Lewis
Page published 05/11/2014 (§1&2) | §3 added 28/04/2019 | §4&5 added 13/12/2021 | §6 added 21/12/2023