THE POTENTIAL OF SEVERAL SPECIES OF TERRESTRIAL SCIOMYZIDAE AS BIOLOGICAL-CONTROL AGENTS OF PEST HELICID SNAILS IN AUSTRALIA

The seasonality, habitat preference and prey acceptability of the terr estrial sciomyzids, Coremacera marginata Fabricius, Euthycera cribrata Rondani, Trypetoptera punctulata Scopoli, Pherbellia cinerella Fallen , and Dichetophora obliterata Fabricius are described. Four of the spe cies (C. marginata, D. obliterata, T. punctulata and E. cribrata) are univoltine and were most abundant in either riverine forest or low scr ubland (garrigue) while one species (Pherbellia cinerella) is multivol tine and was very abundant only in open pasture habitats. All of the s pecies had a wide range of prey acceptability (five to nine species of snails) although they varied widely in their predation efficiency. Th e potential of the univoltine species as biological control agents for pest pasture snails in Australia can be assumed to be poor due to dif ferences between their preferred habitat and the target habitat. Howev er, the multivoltine, pasture-inhabiting species, P. cinerella may hav e potential use, if it can be shown that it will not overlap with the habitat of endemic Australian snails.