Thousands of Beetles to be Released in Manitoba and Saskatchewan Against Purple Loosestrife

By Cory Lindgren
A cooperative environmental project will release 1000's of purple loosestrife eating beetles into Manitoba and Saskatchewan over the next two summers. The Manitoba Purple Loosestrife Project has received a grant from Environment Canada's EcoAction 2000 Fund to set-up 5 mass-rearing satellite stations for purple loosestrife beetles, 4 in Manitoba and 1 in Saskatchewan. EcoAction 2000 funds will be matched by funding contributions from Ducks Unlimited Canada, Manitoba Natural Resources, and the City of Winnipeg. Each satellite station will start with 100 beetles inside specialized insect rearing tents and within 4 weeks 5,000 beetles will be produced per tent for release into purple loosestrife infested habitats. Rearing stations will be located in Winnipeg, Libau Marsh, Morris and Holland (Manitoba) as well as Saskatoon. The Manitoba Weed Supervisors Association will play a large role in the project by rearing insects for release in the Morris and Holland (Cypress River) areas.

Purple loosestrife destroys wildlife habitats by displacing the native vegetation that provides critical food, shelter, and breeding areas for wildlife. There is no Canadian bird, fish or mammal that depends on purple loosestrife for their survival. In fact, loosestrife threatens their survival while reducing the overall biodiversity in our ecosystems. Called an aquatic nuisance species (ANS), purple loosestrife is one nasty plant and an unwelcome invader that is on the Manitoba Noxious Weed Act.

Purple loosestrife is perhaps the most difficult weed to control on the Manitoba landscape. When it escaped it native European homeland some 200 years ago, it also escaped all the natural predators that kept it under control in Europe. Various control methods such as digging, pulling, flooding, spraying, swearing, burning and discing have been tried in North American but have not been successful. It reminds me of a song my three year old son sings..."But the Cat Came Back, the Very Next Day". That is why scientists in Manitoba and Saskatchewan are hoping that a specialized plant-eating insect will provide an answer.

The host-specific (eats and lives only on purple loosestrife) leaf-eating beetle Galerucella calmariensis will be the biological control agent that will be mass reared. This beetle, about the size of a lady-bird beetle and mostly brown, has proven successful in experimental releases in southern Manitoba. Beetle release sites in the Delta Marsh, Portage la Prairie, Netley-Libau Marsh and in the Whiteshell Provincial Park at RedRock Lake have resulted in the elimination of all flowering plants, hence, no seed production. This is a giant step as one purple loosestrife plant is capable of producing as many as 3 million seeds a year! The mass rearing project will hope to increase the rate of which G. calmariensis is introduced into purple loosestrife infested habitats.

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