The English grain aphid (Sitobion avenae) has started to appear across the Prairies in various cereal crops this past week so the time to scout is now. Look for this aphid infesting wheat heads (favourite host) as well as barley, oat, rye, Timothy and canaryseed.
This aphid can also be a vector for barley yellow dwarf virus. You might see the green, red colour morph or both morphs in fields this year (Fig. 1). You will probably also see ladybeetle (@FieldHeroes) adults and larvae hunting the aphids (Fig. 2). The economic threshold for aphids in spring wheat in Western Canada is 12-15 aphids per head prior to the soft dough stage.
Agriculture and Agri-Food Canada, with funding from the Pest Management Centre, has developed a smartphone app called Cereal Aphid Manager (CAM) to facilitate scouting for aphids in cereals that also allows you to record the beneficial insects in the field that can keep aphid populations below the economic threshold – available at Apple iTunes and Google Play app stores. CAM information and download links.
For more information on the English grain aphid, check out our Insect of the Week page!
Submitted by Dr. Tyler Wist (Tyler.Wist@agr.gc.ca).