Ampelomyia viticola

Distinguished from other grape gall makers by the narrow, conical, sometimes slightly curved tubular shape of its galls. The galls are typically crimson (occasionally green), located on upper leaf surfaces, and contain a single smooth-walled chamber. The specific epithet viticola and association with Vitis species helps distinguish it from Ampelomyia species on other host plants. Previously placed in Schizomyia, separation from congeneric species requires examination of larval morphology, particularly the bilobed posterior extremity with prehensile processes and distinctive head spot pattern.

Found in habitats supporting native grape vines, including riparian corridors, woodland edges, and disturbed areas. Galls occur on leaves of wild grape species. Rare in cultivated vineyards.

Eastern Nearctic region: eastern United States and southeastern Canada (Ontario). Type locality: environs of Washington, D.C. Documented in multiple eastern states. Reports from Japan are misidentifications.

Galls present July through August, with records extending to early September (September 8).

Larvae feed on tissue within grape leaf galls; specific feeding mechanism inducing gall formation not described.

• Vitis riparia - gall hostwild grape
• Vitis labrusca - gall hostfox grape
• Vitis vulpina - gall hostfrost grape
• Vitis aestivalis var. bicolor - gall hostsummer grape variety

Developmental stages include egg, larva, pupa, and adult. Larvae develop singly within galls. Specific details of egg deposition, pupation site, and number of generations per year not documented.

Larval development occurs within individual chambers inside leaf galls. Up to 75–135 galls may occur on a single leaf. Galls typically form on upper leaf surfaces.

Forms phytophagous associations with native Vitis species. Galls represent minor plant damage with limited ecological impact; populations usually sparse even where present.

Not considered economically significant to viticulture; galls are rare in vineyards and not particularly harmful to wild plants. Subject of historical taxonomic interest due to complex nomenclatural history involving Osten-Sacken, Walsh, and Riley.

• Other Schizomyia/Ampelomyia speciesSimilar gall morphology; distinguished by host plant association and larval morphological details
• Other grape-inhabiting CecidomyiidaeDifferent gall shapes; A. viticola specifically produces narrow tubular/conical galls with single chamber

Historical reports of occurrence in Japan are erroneous and represent misidentifications of other species.

• gall midge
• phytophagous
• Vitis
• Nearctic
• Cecidomyiidae

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• GBIF taxonomy match
• iNaturalist taxon
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