THE GALL MIDGES (DIPTERA, CECIDOMYIIDAE) OF BACCHARIS SPP (ASTERACEAE) IN THE UNITED-STATES

The gall midge fauna of Baccharis in the United States now includes 12 species. Four species were previously known to attack Baccharis in th e 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 de scribed: 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 Conta rinia sp., and a Dasineura sp., are placed only to genus because of in sufficient material for further determination. Rhogpalomyia baccharis Felt is considered a junior synonym of R. californica. A key is given to the feeding niche for the 12 species.