The origin of the southern African biotype of Chromolaena odorata
Costas Zachariades (Plant Protection Research Institute ARC), Iain D. Paterson (Rhodes University)
The neotropical shrub Triffid weed (Chromolaena odorata) remains a major invasive alien plant in the subtropical regions of southern Africa.
From early in the South African biological control research programme initiated in 1988, it was evident that the form of Chromolaena odorata invading southern Africa ( designated the SA biotype) differed from that invading other parts of the Old World (designated the Asian/West African or A/WA biotype).
Furthermore, for many years no plants identical to the SA biotype were found during exploratory surveys for biocontrol agents in the Americans.
These issues posed a problem for the biocontrol programme in that many of the insects and pathogens collected from other morphological forms of C. odorata developed sub-optimally on the SA biotype.