Prospects for the biological control of silver-leaf nightshade, Solanum elaeagnifolium, in Australia

Abstract

A survey of the distribution of the herbivores associated with the weed, Solanum elaeagnifolium, in its native range in Mexico and south-west U.S.A., has been made in relation to climate. The biological control agents considered were: a leaf-galling nematode, Orrina phyllobia; the defoliating cassidine Gratiana pallidula; chrysomelids Leptinotarsa texana and L. defecta, and tingids, Gargaphia spp.; a stem-boring curculionid, Trichobaris texana; a stem-galling cecidomyid species; the fruit-feeding gelechiid, Frumenta nephelomicta; and tephritid Zonosemata vittigera. The results of the survey suggest that the herbivores would not be sufficiently climatically adapted to the summer-drought, cereal-growing areas of southern Australia most heavily infested by the weed, to control it there. They might establish and be useful in areas less heavily infested by the weed in summer rainfall climates and in irrigated crops.