| | Insects of Britain and Ireland: the genus Phyllonorycter (Lepidoptera-Gracillariidae) |
Synonyms: Phyllonorycter alnifoliella auct. and Phyllonorycter rajella auct.
Associated with trees. On Betulaceae; Alnus (supposedly confined to Grey Alder, Alnus incana).
Larvae. The larvae mining in leaves; in the under-side. Found in July, or September to October. The larva not constructing a definite cocoon.
Pupa. The pupal cremaster with two pairs of hooked processes; two pairs of cremastal processes more or less equal in length; cremastal processes relatively short and basally broad (the outer pair stouter).
Adults. Face white. Head mixed white and fuscous. Thorax sooty brown, or fuscous. Wing-span 7–9 mm. Forewings variable, brownish orange, or golden brown; not clear shining white; with a well defined basal streak (this narrow, straight or only slightly sinuate). The basal streak pale; dark-edged above. Forewings with well defined pale strigulae (white). Costal strigulae 4. Dorsal strigulae 3. Forewings with the first costal strigula approaching a dorsal one at an acute angle; without transverse pale fasciae. Forewings with conspicuous dark apical marking. Forewing apical marking comprising a dark apical strigula. The forewing fringe narrowly dark-lined along the bases of the cilia. The forewing basal fringe line confined to the apical region or fading dorsally, or interrupted (by the third dorsal strigula). Hindwing cilia brownish fuscous.
The left and right male genital valvae similar in size and form (oblong, apically rounded). The left male genital valva not spine-tipped. The left and right male genital valvae having free costae. The left and right free costae arising near the bases of the valvae; similar (including their long curved apical spines, about two-thirds as long as their valvae). The aedeagus long and relatively slender with a triangular barb towards the apex.
Adults abroad May and August.
General comments. Much confused with P. rajella and the mainland-European P. alnifoliella (Hübner), which formerly included both of them. Diagnostic descriptions have proved elusive, and the present description may not satisfactorily distinguish between these species morphologically.
Illustrations. • Phyllonorycter strigulatella: Ian Kimber (2018), UKmoths https://ukmoths.org.uk/. • Phyllonorycter strigulatella: Agassiz (1980), Proc. Brit. Ent. Nat. Hist. Soc. 13–15. • Phyllonorycter species on Alder. 1, Phyllonorycter strigulatella; 2, P. stettinensis; 3, P. froelichiella; 4, P. kleemannella. Representation of the foodplant (Alder, Alnus glutinosa) from Sowerby and Johnson. • Phyllonorycter cf. strigulatella (as L. alnifoliella), genitalia: Pierce and Metcalfe (1935).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the genus Phyllonorycter (Lepidoptera-Gracillariidae) Version: 14th April 2022. delta-intkey.com’.
