Impact of biocontrol agents on Lantana camara in an inland area of South Africa

Abstract

Lantana camara L. (Verbenaceae) is a weed of significant concern in many tropical and subtropical countries. This work aimed to quantify the combined impact of the established suite of lantana biocontrol agents on plant growth under field conditions in an inland area with a continental climate in South Africa. An insecticidal exclusion method was employed to compare plant growth parameters and agent damage between exclusion plants and biocontrol plants. Despite failing to maintain exclusion plants completely biocontrol agent-free, leaf damage was 44% greater, and side-stem production 16% less, in biocontrol compared to exclusion plants. There was a positive relationship between leaf damage and reduction in side-stem production over the study period. Overall, insecticidal exclusion, though only partially effective, showed that the established suite of lantana biocontrol agents is having a measurable growth-inhibitory impact on the target weed.