When to spray for cabbage seedpod weevils. (Photo: 229930687 © Ferenc Somos | Dreamstime.com)

By Jaryn Vecchio

When to spray cabbage seedpod weevils

Jul 8, 2022 | 7:10 AM

PRINCE ALBERT, SK – Cabbage seedpod weevils. These tiny insects are once again starting to become a problem for canola fields in the prairies.

Héctor Cárcamo, a research scientist with Agriculture and Agri-Food Canada, says producers concerned about weevils should sweep the outside of their fields, moving in around 50 metres.

Depending on how many you find, you may need to spray the field.

“If you have more than five weevils per sweep, you could potentially be losing more than two to three bushels per acre.” Cárcamo said the number to really focus on is two. If you’re averaging more than two weevils every time you sweep then spraying is the best option. If you’re averaging two or less, you’re better off leaving them alone.

“If you’re below the economic threshold, say you have less than two weevils per sweep, you shouldn’t worry about spraying because you’re not going to lose yield,” added Cárcamo.

Nighttime construction on Hwy 3 in Lethbridge starts April 17

Apr 17, 2025

SASHA launches #BuyABed fundraiser to support vulnerable Lethbridge residents

Apr 04, 2025

$20K grants available: TELUS STORYHIVE Pan-Asian Edition opens applications April 1

Mar 18, 2025

He noted leaving some weevils can actually be beneficial to the crops. Similar to how vaccines work, if the crops get a little taste of what they’re trying to avoid they can better defend against it.

“The plants get a bit of a scare and there are bugs feeding on me, I need to get stronger.”

Meanwhile, Cárcamo is reminding farmers to avoid sweeping the middle of their fields as nearly all weevils are found on the edges. Farmers should avoid sweeping the same spot every time and try different sides.

Read more Lethbridge News Now.