There are two main species of flea beetles across the Prairies: the striped flea beetle and the crucifer flea beetle.
Both can have devastating impacts on the canola crop, however, they have a few differences between them.
As Héctor Cárcamo, research scientist with Agriculture and Agri-Food Canada (AAFC) at Lethbridge, Alta., explains, the crucifier flea beetle is more often found in the southern parts of the Prairies, with the striped more commonly found in the north.
“If you are in the south, where you have drier conditions — especially in southern Alberta, southern Saskatchewan — basically the brown soil zones, you have the black crucifer flea beetle,” he says. “If you are in more northern areas — more humid areas in northern Alberta, northern Manitoba, you will have the striped flea beetle, even extending to southern Manitoba. So around there, they have more of the striped flea beetle.”
We often think drought equals flea beetles, but this isn’t always the case, especially if looking at the striped flea beetle.
“That one likes more cold conditions, and also it likes more humid conditions,” says Cárcamo.
The economic thresholds between the two species stays the same, at 25 per cent defoliation. There are areas that are seeing both species of flea beetles — which can make spray timing quite tricky.
“If you have a combination of the two insects, it’s very difficult to predict what will happen. But normally, if we have a dominance of the crucifer flea beetle, plant your canola as early as you can,” says Cárcamo. “If you live in northern Alberta, it’s the opposite. If you plant the earliest, then you are probably going to be the trap crop for the striped flea beetle, because that one comes out a little bit earlier. It wakes up from their sleep after the overwintering period, and it will come to whatever canola is planted the earliest.”
Learn more on the differences between the two, below: