Aphids can be a big problem in cereal crops, and populations can build quickly. Knowing if and when to spray can be tricky. Decisions are driven by estimated aphid populations and factors can impact them — weather and natural predators. The new Cereal Aphid Manager app can help.
This app uses considers these factors to estimate whether or not aphid populations will rise to economic threshold levels. It’s based on an earlier model, Aphid Advisor, used by Ontario-based soybean growers for similar purposes.
“I adapted their model and we used their idea of a smartphone application,” said Tyler Wist, Agriculture and Agri-Food Canada field crop entomologist.
The app includes images of the aphid species found in Western Canada, as well images of beneficial insects. It takes you on a scouting path in a W-pattern through the field. At each of the five points, you’ll be directed to count the number of aphids on the tiller of randomly selected cereal heads. Once you enter that number, the app will predict whether or not the crop will reach the economic action threshold in a week or so. “It gives the farmer a heads up to know that there might be problems and it gives him an idea as to if there are actually problems right now,” said Wist.
The app takes beneficial insects into consideration, including parasitic wasps, green lacewing larvae, and adult and larval ladybugs. Female parasitic wasps, for instance, will sting aphids and then lay eggs inside it. While you might never see the parasitic wasp itself, “aphid mummies” are the telltale sign that they were indeed there. “When you’re doing your counts of aphids, if you see mummies then you add that to the counts of natural enemies,” Wist said.
The Cereal Aphid Manager app is free for Android and Apple users.