73.089 Spodoptera littoralis (Mediterranean Brocade)
fw: 14-19mm (Waring & Townsend), 12-16mm (EPPO Bulletin); rare migrant with 10 British records, all Cornwall & Dorset, Sep-Oct
Ref: EPPO Bulletin (Wiley Online Library)
Ref: EPPO Bulletin (Wiley Online Library)
Spodoptera littoralis (Mediterranean Brocade) §1 male (image supplied by Mick Scott)
ID: Sexually dimorphic. Mottled black/brown/pinkish with distinctive cream markings: antemedian line scalloped, turning sharply towards the base at its dorsal end; postemdian line sinuate; dorsum between antemedian and postemedian lines; subterminal fascia; forewing veins; A-shaped outline to kidney mark; flash through and distal to the elongate oblique oval mark in the male (this flash being absent in the female).
Indistinguishable on external features from S.litura (Asian Cotton Leafworm) which has occurred as an accidental import.
Male genitalia: The crucial feature distinguishing S.littoralis from S.litura is the juxta. In S.littoralis this is a transverse plate with broad truncate posterior processes and narrower truncate anterior process, with a concavity between each pair of processes (nb the isolated juxta shown in the EPPO Bulletin paper is shown posterior down while the image of the whole genitalia is shown in the standard posterior up); in S.litura the juxta is ~triangular, narrowing to a central posterior process. Other features are mentioned in the paper that I find less convincing. A feature not mentioned in the paper, but which is apparent on comparison of images, is that in S.littoralis the saccular margin is angular while in S.litura it is evenly rounded.
Female genitalia:
Indistinguishable on external features from S.litura (Asian Cotton Leafworm) which has occurred as an accidental import.
Male genitalia: The crucial feature distinguishing S.littoralis from S.litura is the juxta. In S.littoralis this is a transverse plate with broad truncate posterior processes and narrower truncate anterior process, with a concavity between each pair of processes (nb the isolated juxta shown in the EPPO Bulletin paper is shown posterior down while the image of the whole genitalia is shown in the standard posterior up); in S.litura the juxta is ~triangular, narrowing to a central posterior process. Other features are mentioned in the paper that I find less convincing. A feature not mentioned in the paper, but which is apparent on comparison of images, is that in S.littoralis the saccular margin is angular while in S.litura it is evenly rounded.
Female genitalia:
§1 St Mary's, Isles of Scilly; 29/10/2022; male; fw 17.4mm; 10th record for Britain; (specimen light-trapped by Mick Scott)
All images © Chris Lewis
All images © Chris Lewis
Page published 15/01/2023 (§1)
