With the wet and cool conditions that growers have been experiencing, we realize there will be a significant amount of fungicide spraying on the wheat crop over the next month. We want to address information we are receiving that many growers will automatically add an insecticide to the mixture because 1) a spray application is already being done and 2) the addition of an insecticide is relatively cheap.
We want to make is clear that this is not a very good Integrated Pest Management, or IPM, approach to managing insect pest populations. Indeed, in most wheat fields, there are no pests that will even get close to economic levels, assuming that they are in the field in the first place. Aphid populations are rarely high enough to cause concern, and any virus transmission would have already occurred. Although we had an initial concern with armyworm, word from Kentucky suggests that they perhaps will not be that high, and an insecticide spray might kill off all the predators and parasitoids that help keep armyworm under control (see adjacent picture for an armyworm with a parasitoid egg). Cereal leaf beetle problems are still infrequent in Ohio. And we would point out that all of these pests can be scouted for and managed if necessary.
We still maintain that an IPM approach is the best way to manage pests, protect beneficial insects, and promote good environmental sustainability. Although it is easy and cheap to apply insecticides, we urge growers to think about the overall benefit in NOT applying an insecticide.