First release of a fungal classical biological control agent against an invasive alien weed in Europe
In the summer of 2014, the rust fungus Puccinia komarovii var. glanduliferae was released in the United Kingdom against Impatiens glandulifera (EPPO list of invasive alien plants) in a set of experimental field trials. I. glandulifera is native to the western Himalayas (India and Pakistan) and it was in the Kullu Valey, India where the rust was first discovered infecting the stem and leaves of plants in high altitude populations. P. komarovii var. glanduliferae is an autoecious host specific fungus that has been evaluated as a biocontrol agent since 2010. The rust underwent safety testing where over 70 closely related, or economically important plant species were tested for susceptibility following internationally recognized scientific protocols. The biology of the rust was evaluated, including life cycle evaluation and dew and temperature requirements for spore germination. These studies confirmed that the rust has five spore stages with temperature and dew period requirements (aecia and urediniospore germination) for which the UK climate is conducive.
Sources
Tanner RA, Pollard KM, Varia S, Evans HC, Ellison CA (2015) First release of a fungal classical biocontrol agent against an invasive alien weed in Europe: biology of the rust, Puccinia komarovii var. glanduliferae. Plant Pathology DOI: 10.1111/ppa.12352.
Tanner RA, Ellison CA, Seier MK, Kovács GM, Kassai-Jáger E, Berecky Z, Varia S, Djeddour D, Singh MH, Csiszár A, Csontos P, Kiss L, Evans HC (2015) Puccinia komarovii var. glanduliferae var. nov.: a fungal agent for the biological control of Himalayan balsam (Impatiens glandulifera). European Journal of Plant Pathology 141, 247-266.