Moths may be a match for invasive oxeye daisy

A European moth is being used in parts of Western Canada as a biological control agent against oxeye daisy, an invasive plant that threatens forage crops and pastures.

The white-flowered plant, native to Europe, has spread aggressively through regions of British Columbia and the Prairies, where it reduces the quality and quantity of forage available to livestock, according to Agriculture and Agri-Food Canada (AAFC). It also interferes with the production of crops, such as timothy hay and alfalfa.

Researchers from AAFC say controlling oxeye daisy is challenging, since the plant often grows in areas that are difficult to access with equipment, making conventional control methods like herbicide application and mowing often ineffective. These methods can also damage native plant species.

“It occurs right across Canada … but it’s a problem for farmers,” said Rosemarie De Clerck-Floate, a research scientist with AAFC who is leading the work with oxeye daisy control. “It takes over; it crowds out other forage species that are desired. Cattle tend to avoid it. It’s not a preferred plant.”