Western Corn Rootworm has been scouted by the Ministry of Ag in BC this past summer.
There are two species of corn rootworm: Western and Northern. The Western Corn Rootworm (WCR) is the only one that has been found in BC at this point. NOTE: the beetle has been scouted in Southern MB this season as well so get ready to scout. I am checking on whether it has been spotted in AB or Southern SK.
Description: Yellow/green body with black stripes on the wings. Larvae are white with brown head and approximately 1 cm (much smaller than that Corn borer larvae.
Life Cycle: One generation per year. Eggs laid in corn field soil from July to Fall. Eggs overwinter and hatch in late May/early June (10 degrees C). Adults emerge late July to feed on silks/pollen/leaf.
Chart from Perdue University Website
Damage: Larvae feed on the roots mid June – mid July affecting nutrient/water Uptake. Can cause plant to lodge/gooseneck. Adults feed on silks/pollen affecting pollination. If not present, they will feed on leaves stripping tissue. Note to scout the larvae, you should removed a large amount of dirt around the root and either soak or gently remove soil. As well, if you have seen WCR beetles in the field this year, you will see them again next year unless you rotate out to another crop.
Management: Rotate Crops. Corn on corn creates perfect storm for their population increase.
Insecticides: Can be used but overall only reduce population by about 25% in a field.
Traited Hybrids: Plant hybrids that have a Corn Rootworm trait. In our line up of corn, the Pride Seed hybrids with a G3 or G8 trait can control Western Corn Rootworm issues.
NOTE: January 2017 at the Pacific Ag Show in Abbotsford, the Ministry of Ag will have a presentation on the issue with information on scouting and follow up for the 2017 season
Information sited from Ministry of Ag ONTARIO website and Perdue University website.
Alexis Arthur – December 2016