Rabdophaga salicisbrassicoides

Distinguished from other Rabdophaga species by the characteristic rosette or cabbage-like gall morphology on willow hosts. The gall structure differs from the elongated shoot galls or bud galls produced by related species. Adult identification requires examination of antennal structure and genitalia.

Associated with willow-dominated riparian areas and wetlands where Salix exigua (sandbar willow) occurs. Galls form on actively growing shoots of host willows.

Recorded from the United States, including Vermont. Distribution corresponds with that of its primary host Salix exigua in western and central North America.

Adults emerge in late April. Larvae overwinter within galls.

• Salix exigua - host plantPrimary host; galls induced on shoots
• Chaitophorus - indirect associationAphids present on same host plants, involved in mutualism with ants that may benefit gall midge
• Formica neoclara - indirect associationAnt species that tends Chaitophorus aphids on host willows; this mutualism has been observed to benefit gall midge populations

Larvae develop within rosette galls on willow shoots. They overwinter inside the gall structure. Adults emerge in late April to initiate the next generation.

Acts as a gall inducer, causing localized growth distortion in willow shoots. The gall structure provides protected habitat for larval development. The species has been observed to thrive in association with ant-aphid mutualisms on host plants.

• Rabdophaga rosariaAlso produces rosette galls on willows; may require gall and host specificity details for separation
• Rabdophaga strobiloidesProduces cone-like willow galls with distinct morphology from the cabbage-like rosettes of R. salicisbrassicoides

• gall midge
• willow gall
• rosette gall
• ant-aphid mutualism

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• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life