Your Reading List

Leafy spurge control

Brought here as a decoration, leafy spurge has become a real problem. Biological agents are one way to control this weed

Leafy spurge takes over pasture grasses and causes scours and mouth blistering in cattle that graze it. Leafy spurge was first brought to southwest Saskatchewan in 1914, by the Oevray family who homesteaded there in 1912.

Mrs. Oevray’s sister in Switzerland sent her some garden seeds, and amongst them was leafy spurge. The following few seasons, Mrs. Oevray was very proud of her nice yellow flowers that regrew every year. Little did she know of the problems her flowers would cause in the future.

Controlling leafy spurge

When the Meyronne Comm-unity Pasture opened in 1957 there was about two acres of leafy spurge. As the years passed, it got worse. That section was fenced out from the rest of the pasture. Sheep corrals were built and 2,200 sheep were brought in from various parts of the province.

The sheep controlled the leafy spurge well. But by this time other patches were appearing. The provincial government supplied 45 gallons of 2,4-D every fall, and I would spray these patches with a hand sprayer.

As the years went by, the spurge got worse.

By the 1980s, we were using Tordon 22K on 100 acres every year. Nothing grew the following year, but the year after that the grass came back, and leafy spurge would start again, with a head or two every 30 to 40 feet.

Since Todon was very costly, the provincial government bought leafy spurge bugs. The flea beetles survived in the fields, and two years later we were able to harvest some. We did this by catching the bugs with fish nets lined with flour bags, trapping hundreds with each sweep.

Flea beetles

One of the most effective methods of leafy spurge control is the use of biological agents like the leafy spurge beetle.

Adult beetles emerge in late June or early July. They feed near the top of the spurge shoots and along the leaf edges. After mating, the females lay their eggs in groups of 20 to 30, below the soil surface near the spurge root.

The eggs, which may number up to 300 in a season, hatch in about three weeks. The larvae bore through the soil until they encounter a small spurge root, on which they feed.

As the larvae grow, they feed on larger roots. After about two months, feeding stops. The larvae go dormant in the winter and resume feasting in the spring.

They pupate in the soil, and emerge as adults. It is the larvae that area primarily responsible for the control of the spurge, with the destruction of the root system. Their feeding depletes the plants nutrient reserves. The plant is no longer able to flower and it eventually withers and dies.

By collecting leafy spurge flea beetles, farmers could establish beetle colonies on their own infested pastures.

About the author

Emile Frerotte's recent articles



Stories from our other publications