Begin Scouting Spring Wheat in Eastern/Central
Ontario for Armyworms

Paul Sullivan (PT Sullivan Agro Limited) has reported finding up to 3 armyworm per square foot at about ½ to ¾ inch in length in spring wheat. Now is a prime time to scout fields.

Fields need to be scouted to determine the number and size of the armyworms. Look deep down in the canopy as the smaller armyworms tend to feed on the lower part of the plant and they hide at the soil surface. Control is warranted when there are four unparasitized armyworm larvae, smaller than 4 cm (11/2in.), per square foot or if head clipping is occurring. To scout, examine 20 plants from five locations in your field to determine the level of infestation. Record the size and number of larvae. When scouting, check the backs of armyworms for parasite eggs. These small, oval, yellowish eggs are usually located just behind the head of the larva. These are eggs of a parasitic fly whose maggots will kill the armyworm larvae. If there are other grass type crops such as corn or grass hay fields nearby the armyworms will 'march' over to the next crop. Spraying the border of these fields may be sufficient to stop the armyworms. Scout these fields too. Note that the pre-harvest interval for most control products is 14 to 28 days depending on the product and the crop to be treated. For further information see OMAFRA Publication 812, Field Crop Protection Guide, for recommended insecticides.

Matador is now registered at the 34 ml per acre for armyworm on wheat, barley and oats. Do not apply within 28 days of harvest or 14 days of livestock foraging.