Predicting insect outbreaks isn’t an easy task, as we learned from insect management specialist with Alberta Agriculture and Forestry, Scott Meers. Even small changes to what was expected from the weather can skew data.
But, understanding forecasts and what impacts populations can certainly help farmers get a better idea of when and where to focus their scouting efforts.
In an interview filmed at Farmtech (and included below), RealAgriculture’s Shaun Haney caught up with Meers (in our fancy studio) to discuss this year’s insect forecasts for the province, and to learn a little more about the weather events that impact populations.
The Good News
Overall, bertha armyworm numbers are suggesting a downward trend off of an outbreak.
For diamondback moths, we’ll have to exercise some patience, and wait for information on spring flights (they actually arrive on airflows from the States, and therefore depend on overwintering conditions there, and spring/summer winds).
“We do seven major surveys every year,” said Meers. “Right now wheat stem sawfly numbers are quite down, but they made a small resurgence in 2015. So there’s some specific areas where we expect more wheat stem sawfly than we did the previous year.”
Wheat stem sawfly populations seem to be driven by dry conditions, Meers explained, with a correlation to greater parasitism during wet years.
The Less-Than-Good News
Pulse growers will have to keep an eye out for pea leaf weevils this year.
“We’re recommending if you’re growing peas or faba beans in the Red Deer/Lacombe area, and even north up into…Wetaskawin that you seriously consider using a seed treatment,” said Meers, explaining that that’s a standing recommendation south of Highway 1, but that the area has expanded for this year.
Cabbage seedpod weevil is also making moves this year.
After many years of watching cabbage seedpod weevils along Highway 1, the last couple of years have seen the pest move into Wheatland, Starland, and even Kneehill Counties, with the northern-most edge in and around Lacombe.
“This year I’m recommending any canola producer that’s growing canola in the line between Red Deer and Provost and south should be scouting — especially first in flower fields.”
The Slightly-Worse-Than-Good-But-Slightly-Better-Than-Bad News
Producers around Falher and Vegreville will have to keep an eye out for wheat midge, warns Meers, especially if the areas see a wet June, but overall, the risk is down for the province.
Cereal leaf beetle may be worth watching this year as well.
“We now find cereal leaf beetle all the way from the Lethbridge area — where’s it been for 5, 6, 7 years now — and up into Edmonton…and now in the Red Deer region.”
As for grasshoppers, it’s one ugly forecast map, but it all depends…
“…If we get a wet spring, especially with the right timing, with rainfall in that May/June timeframe, we could very, very little impact from grasshoppers,” said Meers. “If we get a dry spring, we’re poised for grasshopper problems in the Peace, Edmonton region, and parts of southern Alberta as well.”