This cooler, wet weather seems to have delayed plant growth but also has been ideal for pests to build in fields or do more feeding while the plant growth is slowed.
Cereal aphids have been spotted in several fields from Harrow to Stratford. Though cereal aphids can often be found at low levels in cereals, without reaching threshold, this year poses an increased risk with so much barley yellow dwarf virus (BYDV) already present across the province. Aphids can probe infected plants and carry them to other fields to infect healthy plants. BYDV takes some time inside the aphids before being able to transmit to other plants. So controlling the aphids via insecticide seed treatments in winter wheat can be a useful tool, especially if those fields are planted earlier than the optimal planting dates, which are in place to reduce the risk of helping bridge aphids moving from corn, cover crops and other grass crops to winter cereals.
Cereal aphids themselves, rarely cause direct yield loss in Ontario. Only when populations reach an average of 12 – 15 aphids per stem prior to heading is a foliar insecticide recommended. But some fields may build to those levels this year if temperatures remain cooler than normal, so scouting is advised. Once in heading, populations need to reach closer to 50 or more aphids per head to warrant control. Keep in mind, many of the natural enemies that help keep cereal aphid populations in check also move to other crops like soybeans to help us out if aphids show up there too. So monitor what natural enemies populations are like while scouting for aphids and consider them when making your management decision. More info on cereal aphids can be found in this link (CropIPM) and control options can be found in this link (Crop Protection Hub).
Black cutworm moths have been arriving in Ontario for more than a month now and neighbouring states have seen abundant flights this year. A few fields in Elgin and Middlesex Counties reported having active cutworm larvae and injury. Some of the larvae were quite active in the field during the cloudy, wet days to make it easier to find them and small enough to still recommend a foliar insecticide for control. But best to scout high risk fields along Lake Erie or those planted without insecticide treatment or Cry1F or Vip3A Bt proteins. Fields with heavy weed mats earlier this spring were ideal for egg laying. Well-timed foliar sprays can provide good control if infestations are spotted early enough. I covered more info on black cutworm in an FCN post earlier this month that can be found at this link.