Pulse School

Scouting the Elusive Pea Leaf Weevil


Manitoba does not have pea leaf weevil but you may hear about it from counterparts in Saskatchewan and Alberta.

The pea leaf weevil can cause devastating economic losses to both peas and faba beans. Though the adult beetles feed on these crops after overwintering in perennial legumes, it is actually the larvae that cause the greatest damage.

Larval feeding occurs on Rhizobium nodules for roughly six weeks. This may limit or completely inhibit nitrogen-fixation by the plant. Thus, crops on land with high nitrogen availability are less likely to suffer damage from the pea leaf weevil. Otherwise, feeding damage results in poor growth and decreased yields.

One of the greatest challenges with scouting for pea leaf weevil (which should begin immediately after the crop has emerged) is the adult’s elusive nature. No matter how sneaky you think you are, it’s likely the adults will drop to the ground before you have a chance to see them.

In this Pulse School, Ken Coles, general manager of Farming Smarter, talks about the action thresholds for pea leaf weevil and advice on what to look for when scouting.