Many species are economically significant, especially the Hessian fly, a wheat pest, as the galls cause severe damage. Other important pests of this family are the wheat blossom midge "Sitodiplosis mosellana", the Asian rice gall midge ("Orseolia oryzae") and the African rice gall midge "O. oryzivora". The millet grain midge ("Geromyia penniseti"), sorghum midge ("Contarinia sorghicola"), and African rice gall midge ("Orseolia oryzivora") attack grain crops such as pearl millet in Mali and other countries of the Sahel in West Africa.