Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/17/1995
Publication Date: N/A
Interpretive Summary: Several species of Baccharis spp. are weedy shrubs that invade pastures, rangelands, and recreation areas, and are unpalatable or noxious to livestock. A survey was made of gall midges that feed on these plants to learn which may be effective in biological control in the United States or elsewhere, where some species of Baccharis have escaped, and to have baseline information before any species are introduced from South America onto North American species. Twelve species of gall midge were found, three new to science. These three are described and the remainder redescribed in this paper. A key to damage by these species is given so that they may readily be identified in the future. This information will be useful to APHIS/PPQ identifiers and scientists working in integrated control of noxious weeds
Technical Abstract: The gall midge fauna of Baccharis in the United States now contains 12 species. Four species were previously known to attack Baccharis in the United States: three species of Neolasioptera, N. baccharicola Gagne, N. lathami Gagne, and N. rostrata Gagne, and Rhopalomyia californica Felt. Three new species and a new genus to contain one of them are described: Asphondylia bacchariola Gagne, Rhopalomyia sulcata Gagne, and Xipholasioptera Gagne and its monotypic type species Xipholasioptera ensata Gagne. Five other species, three species of Asteromyia, a Contarinia sp., and a Dasineura sp., are placed only to genus because of insufficient material for further determination. Rhopalomyia baccharis Felt is considered a junior synonym of R. californica. A key is given to the feeding niche or galls of each of the species.