Species Rhopalomyia grossulariae - Gooseberry gall midge

The title of Houser's (1912)(1) paper is "The gooseberry gall midge or bud deformer"

Gagné (2010, p. 413)(2) placed this species in the "Unplaced species of Cecidomyiidae" section of the catalog.

This insect is named after the species name of its larval host plant, Ribes grossularia (now a junior synonym of Ribes uva-crispa).

See Identification.

Length of head + body of adult, 1.8-2.0mm. Head and thorax brown, abdomen with marked reddish tinge (apparently a common color pattern within this genus). Structural characters as for the genus (Rübsaamen 1892)(3). Felt (1911)(4), in the original description of this species, wrote, "This form, in antennal characters, approaches the North American Rhopalomyia tridentatae Rubs. (sic) reared from Artemisia, though it is easily distinguished therefrom by the uniarticulate palpi." As with probably many species of this genus, rearing is the best way to acquire reliably-determined individuals of R. grossulariae.

The species was described from a single locality in Ohio, and Gagné (1989, 2004, 2010)(5)(6)(2) gave Ohio as the known range. The Illinois record submitted here is apparently the first for the state.

Matches the habitat of gooseberry, which is an understory plant of deciduous forest in the eastern USA.

See Life Cycle.

Larvae are specific on buds of gooseberry, Ribes spp.. Adult feeding habits are not known; it is possible that adults do not feed, as evinced by their very short lifespan.

One generation per year. Galls should be sought when gooseberry is beginning to leaf out in spring (late March or early April in central Illinois); adults emerge shortly after the appearance of mature galls.