Isochnus sequensi

As a member of the flea-weevil tribe Rhamphini, this species likely possesses enlarged hind femora adapted for jumping. Definitive identification requires examination of genitalia and other microscopic features; leaf mines on Salix fragilis in combination with adult morphology may support identification in its known range.

Associated with Salix fragilis (crack willow), where larvae develop within leaf mines. The Saint Petersburg study site indicates tolerance of temperate, continental conditions with human-modified landscapes.

Recorded from Belgium (multiple occurrences), New Brunswick (Canada), and the environs of Saint Petersburg, Russia. The Russian population has been studied in detail; broader Palearctic and Nearctic distribution likely but not confirmed by available sources.

Larvae feed internally on leaf tissue of Salix fragilis, creating mines. Adult feeding habits not documented in available sources.

• Salix fragilis L. - host plantcrack willow; sole documented host for leaf mining
• Cirrospilus pictus - parasitoidEulophidae: Eulophinae
• Cirrospilus diallus - parasitoidEulophidae: Eulophinae
• Minotetrastichus frontalis - parasitoidEulophidae: Tetrastichinae
• Chrysocharis nephereus - parasitoidEulophidae: Entedoninae

Larval development occurs within leaf mines on Salix fragilis. Adults emerge from these mines. Specific details on egg placement, pupation location, voltinism, and overwintering stage not documented in available sources.

Larvae are leaf miners, feeding between the upper and lower epidermis of willow leaves. This concealed feeding strategy provides protection from predators and desiccation.

Functions as a specialist herbivore on Salix fragilis. Serves as host for at least four species of eulophid parasitoid wasps, contributing to local parasitoid community structure.

• Other Isochnus speciescongeneric weevils also associated with Salix and Populus; require morphological examination for separation
• Other Rhamphini leaf miners on Salixsimilar leaf mine morphology and host use; adult identification necessary for species-level determination

• leaf miner
• willow-associated
• flea-weevil
• parasitoid host

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• Eulophid Wasps (Hymenoptera, Chalcidoidea: Eulophidae), Parasitoids of Isochnus sequensi (Stierlin) (Coleoptera, Curculionidae: Rhamphini), a Leaf Miner on Salix fragilis L., in the Environs of Saint Petersburg, Russia