By Tracey Baute and Meghan Moran
Spring canola producers will have the option of Buteo (flupyradifurone) or Lumiderm (cyantraniliprole) insecticide seed treatment on some varieties this year, in addition to the Helix Vibrance seed treatment. Producers have reported they prefer Buteo for managing flea beetles, but that is the only insect on the Buteo label. Northern Ontario producers have battled cutworm species in recent years and Lumiderm is registered for both flea beetle and cutworm management.
In 2024, a variety of different cutworm species were found causing crop injury in Ontario. It can be difficult to properly identify cutworms found in the field and some producers may not know exactly which one they were dealing with. Dingy cutworm can overwinter as larvae in Ontario, while variegated cutworm does not. Black cutworm overwinter as pupae (immature form between larva and adult moth) as far north as Ohio and potentially parts of southwestern Ontario, but this is unconfirmed. Black cutworm moths emerge, then choose which fields to lay their eggs in. Species that overwinter south of Ontario also fly in as moths to lay eggs in Ontario canola but infestations by these migratory species are more sporadic and not always guaranteed. It is difficult to guess what the risk of cutworm injury will be, though some high-risk factors like weedy matts in early spring can increase risk. Proper identification of the cutworm species is important to better understand what risk factors are driving infestations.
Having a cutworm issue once every 5 years in canola would warrant careful and frequent scouting early in the season but may not be a reason to move away from products with better control of flea beetle, which is a known risk. Rescue treatments using foliar insecticides can be effective if cutworm damage is found early enough that the larvae are not too big to control (2.5 cm). Producers that are routinely dealing with cutworms in canola might consider using Lumiderm seed treatment to help manage cutworms while still offering flea beetle management. It’s important to keep in mind that seed treatment insecticides are less effective two or three weeks after planting once the seed has started to imbibe water, so continued scouting is critical.
More information on the different cutworms found in Ontario in 2024 and how to effectively scout for them can be found HERE.
Photo credit: T. Cowan, MOE