The benefits to sub-Saharan Africa of the biological control of weeds: already considerable, but could be far greater

Abstract

Sub-Saharan Africa (SSA) is climatically diverse, with many biomes. Many species of invasive alien plants (IAPs) are present, with severe negative impacts that largely remain unquantified. Importation biological weed control (IBWC) has been practiced on the continent since the early 20th century, with some notable successes. Weed biocontrol agents (WBA) (141 species) have been released in 30 countries on 69 weed species, and spread to a further eight countries. South Africa has the most active IBWC program, while several projects are underway in other countries, involving either the release of WBA or monitoring of their spread and impact. However, given the large and increasing footprint of IAPs, and the poor prospects for their successful management using other control methods, we discuss reasons for the relatively low uptake of IBWC in SSA, and suggest ways to increase this.