Rhopalomyia lawrenciae, a new gall midge species (Diptera : Cecidomyiidae)deforming leaves of Lawrencia squamata (Malvaceae) in South Australia

A new gall midge, Rhopalomyia lawrenciae, is described from swollen leaves of Lawrencia squamata collected on Hindmarsh Island in the River Murray est uary, South Australia. Inside each of the infested leaves is a chamber occu pied by one larva of the new species. Males, females, pupae and larvae of t he gall midge are described. All specimens of the host plant lodged in the State Herbarium of South Australia were examined for galls and this reveale d a wide geographic distribution throughout the state. A key to adults of t he three known Rhopalomyia species occurring in Australia, R. lawrenciae, R . goodeniae, a native species damaging stems of Goodenia lunata and R. cali fornica, an introduced American species damaging flower buds of Baccharis h alimifolia, is provided.