The invasive weed ox-eye daisy, 'Leucanthemum vulgare' Lam. (Asteraceae): Prospects for its management in New South Wales

Ox-eye daisy, Leucanthemum vulgare Lam. (Asteraceae) is a rhizomatous perennial herb, native to Europe that has become an invader in over 40 countries (including Australia and New Zealand). Seed longevity is high and up to 80% of propagules are viable for six years. The weed is not palatable to cattle and affects pastoral lands by reducing carrying capacity. Dense infestations exclude other plant species, leading to soil erosion and depletion of soil organic matter. Ox-eye daisy is found in Victoria (where it is a declared noxious weed) and New South Wales (where one of the more alarming infestations is in Kosciuszko National Park). The species appears to thrive in disturbed areas, however, of greatest concern is its ability to aggressively invade areas of conservation importance. While mechanical and chemical control can be successfully implemented to manage localised infestations of ox-eye daisy, there is an urgent need for the sustainable management of this invasive plant at the landscape level, especially in conservation areas. In 2008, a programme was initiated to investigate the prospects for the biological control of ox-eye daisy in North America. Over the last seven years CABI Switzerland have identified and studied several promising biological control agents including a root-feeding moth, Dichrorampha aeratana Pierce and Metcalfe (Lepidoptera: Tortricidae), a root-feeding weevil Cyphocleonus trisulcatus Herbst (Coleoptera: Curculionidae) and a flower head-mining fly, Tephritis neesii Meigen (Tephritidae). Of these, D. aeratana seems to hold the most promise in terms of specificity and is being developed further as the first biological control agent for North America. In early 2015, a programme to investigate prospects for the classical biological control of ox-eye daisy was initiated for New South Wales. The programme will include: 1) selecting and determining the biology, host range and impact of the most suitable agent for the state; and 2) assessing through modelling, the ecoclimatic tolerances of the agent and the weed (CLIMEX and Degree-day) as well as the environmental impact of this and other management approaches (Life Cycle Assessment).