Natural enemies of Convolvulus arvensis in western Mediterranean Europe.

Because of interest in biological control for Convolvulus arvensis L. in the USA, a survey of its fauna was conducted in Mediterranean Europe. In all, 140 species of insects, three species of mites and three pathogenic fungi were found attacking C. arvensis and other closely related members of the Convolvulaceae. Most organisms were associated with the leaves, but, considering the amount of root material available, very few were found on the roots. About half of the arthropods are widespread and important C. arvensis herbivores, but most are polyphagous and many are known crop pests. None is strictly monophagous on C. arvensis. The seasonal progression of plant growth and the presence of the more important arthropods associated with various plant parts are described. After considering literature records of their host specificity and field observations of plant damage and biology, 15 species most widespread and damaging to C. arvensis were tested for their ability to live on sweet potato. Galeruca rufa, Eriophyes sp. and Spermophagus sericeus were considered to have the greatest potential as biocontrol agents, while six other insects and one fungus may be of value.