Canola School: When to worry about aphids
There are several species of aphid that are a pest on several crop types, but on the bright side, there’s only one species of aphid canola farmers need to worry about.
As Sean Prager, assistant professor of plant sciences at the University of Saskatchewan explains, it’s the green peach aphid, or Myzus persicae, that causes damage to canola. The pest is roughly the size of a pin head, and is mostly green in colour but some can be red depending on what its eating.
Signs of green peach aphids in canola can include:
- Signs of wilting, or what would look like water stress;
- Considerable amounts of the pest itself; or,
- Large amounts of honeydew on the plant.
In terms of economic thresholds, there are none for aphids in canola, according to Prager, who adds there are no recommended sampling plan for the Prairies.
“There are plans for other places, but generally we don’t think of them as being particularly large pests in canola, and a lot of the other insects we manage are managed with insecticides that will handle aphids, so that also tends to keep the risk lower,” Prager says.
“The only thing that makes aphids a little bit different is that they are vectors of disease, and while we don’t really see any of that here, there’s the potential that if you have large aphid outbreaks you can also have some viruses that are vectored by the aphids.”
Listen below to the full conversation on aphids in canola and what to look for in the crop: