BIOLOGICAL-CONTROL OF LANTANA-CAMARA (VERBENACEAE) IN SOUTH-AFRICA

Lantana camara L., a fast-growing verbenaceous shrub from Central and South America, is a toxic invasive weed in many countries. Taxonomically, L. camara is a complex of several cultivars (forms) whose diversity has frustrated attempts at biological control by insect natural enemies that show preferences for some cultivars and an inability to survive on others. Of the 16 insect herbivore species imported into South Africa for biological control of L. camara, six have become established and two were already present. Two leaf-feeding chrysomelid beetle species. Octotoma scabripennis guerin-Meneville and Uroplata girardi Pic, usually in association with the tingid bug, Teleonemia scrupulosa Stal. are exerting some degree of control. A seed-feeding agromyzid fly, Ophiomyia lantanae (Froggatt), may be contributing to the overall stress on the plant, but its contribution to biocontrol has not been determined. A flower-feeding pyramid moth, Salbia haemorrhorrhoidalis Guenee, is established in low numbers at isolated sites over a wide area. A noctuid moth. Hypena strigata (F.), an African species that was mistakenly 'imported' into South Africa, contributes little to biocontrol of L. camara in this country. although it was very successful in Hawaii. The biocontrol of L. camara in South Africa, with its problems and shortcomings, is reviewed and the future of the programme is discussed. A better understanding of the functional relationships and interactions between the various cultivars of L. camara and insect herbivores may improve the chances of succeeding with biological control.