Diamondback moth larvae need to be on farmers early season look out list.

Heavy feeding by the larvae isn't good news for young canola crops.

Ward Toma, General Manager for the Alberta Canola Producers says the larvae have been spotted mainly in Southern Alberta and are reaching thresholds where spraying may be required.

"It's a bit earlier than usual and they are showing heavy feeding on some of the smaller plants and that is going to affect how the plant is going to grow and mature."

Growers cannot expect insecticide seed treatment to protect canola from diamondback moth larvae.

"Before spraying, farmers should be looking for areas in a field that have reached 25% threshold or more of the leaf area lost to feeding by the larvae. They have to be able to see that the larvae are still there. If they have started to go into a cocoon stage then they are no longer a threat," Toma advises. "Look out for little green worms."