We’re seeing a huge resurgence of Japanese beetles in the fields this summer, despite the populations being fairly low in most recent years. Japanese beetles are general defoliators. The good news is they tend to feed on a single leaf, and stay on that leaf.
As you can see here, they’ve fed on those top leaves, but the leaves around it remain untouched:
We don’t evaluate defoliation based on a particular leaf, but rather whole plant defoliation. So even though these photos – taken in Wayne County – look really terrible, the loss is fairly minimal.
Japanese beetles give off a pheromone, which attracts other beetles in. Many times, you can notice a few feeding, but by the end of the day you’ll have massive amounts of beetles feeding on areas of the field.
The damage from Japanese beetles will typically be fairly localized. We’ve seen farmers hang a boom over the edge of the concentrated area and take care of it that way. There may be, however, such concentrations that farmers will be more inclined to spray the whole field, especially if they’re going to apply a fungicide soon. We recommend adding another insecticide such as Delta Gold® and taking care of them that way.
As always, your YieldPro Specialist is available to answer all of your questions. We encourage you to reach out to them if you have any concerns.
