Author
Marion K Seier
m.seier@cabi.org
CABI
Silwood Park, Ascot, Berkshire, UK
Coauthors
Harry C Evans, CABI, Silwood Park, Ascot, Berkshire, UK
Abstract
Their damaging nature combined with high host specificity can make fungal pathogens highly effective classical biological control (CBC) agents of invasive alien weeds. Testimony to this are successful CBC initiatives, such as control of: Ageratina riparia by the white smut Entyloma ageratinae (New Zealand, South Africa, Australia); Acacia saligna by the gall rust Uromycladium morrisii (South Africa); and Mikania micrantha by the rust Puccinia spegazzinii (Pacific region). Nonetheless, to date, only 42 intentional CBC introductions of fungal pathogens have been made against invasive alien weeds worldwide – a fraction of the 536 releases in total. Whilst research on fungal pathogens for weed targets is progressing, and release applications for selected agents are in the pipeline, there are also promising weed pathology initiatives that have been abandoned in the past for various reasons, including; host-specificity, life cycle and political issues. This talk will re-visit some of these weed-pathogen associations which we believe should be given a second chance, namely: Mycosphaerella polygoni-cuspidati–Reynoutria japonica and Phloeospora heraclei–Heracleum mantegazzianum in the UK; Sporisorium ophiuri–Rottboellia cochinchinensis in Central America; and, Puccinia spegazzinii–Mikania micrantha in India and China.
Keywords
invasive alien weeds
fungal pathogens
classical biological control
phylogenetics
host specificity
Highlights
Examples are given of successful classical biological control (CBC) projects using fungal pathogens
Fungal pathogens have been under-utilised as CBC agents for invasive alien weeds
Recommendations are made to improve success chances for ‘failed’ CBC projects using fungal pathogens