I think the last 3 or 4 articles I have put out have been about insects, much of that is due to the wet year being conducive to large outbreaks of various insects. This week I am writing about grasshoppers, an insect that usually is not an issue during wet years. Typically, during a wet spring most of the young grasshopper nymphs (before they get wings) will die from all the rain. It has been a big surprise to me and smarter than me entomologist, that we have a large population of grasshoppers this year. In many areas I have seen grasshopper populations well above economic threshold levels.
We think that during the slight dry spell we had back in the early spring gave the grasshopper nymphs time to get large enough to survive all the rainfall we have had since. You can estimate the number of grasshoppers you have just by walking through your fields. Use the following levels to help make treatment decisions. At 3 to 7 hoppers per square yard you would have only light damage, at 8 to 14 you would reach the economic threating level where it should pay to take some preventive action and spray for your grasshoppers.
There are many good products you can use to manage grasshoppers, two that have some good residual control include Dimilin and Prevathon. Dimilin provides up to 6 weeks of residual control, as long as the treated forage is not harvested. Dimilin will only work on small grasshoppers; once they sprout wings Dimilin is not effective. Dimilin will cost $2.00 to $3.00 an acre. I probably should not even mention Dimlin as the grasshoppers I am seeing are already winged and Dimilin will not be effective. Prevathon provides excellent control later in the year and will work on the larger grasshoppers we have now; it will provide up to 6 weeks of residual control and cost around $13.00 an acre. Other good insecticides that provide immediate results, but do not have lots of residual control include any generic products containing lambda cyhalothrin, which cost approximately $3.40 per acre, and Mustang Max which cost around $4.75 an acre to treat. There are other pasture products available, but these tend to be the most cost effective.
For homeowners trying to control grasshoppers in their yards, landscapes and gardens Cyfluthrin, bifenthrin, permethrin, cyhalothrin and carbaryl are some of the active ingredients that control grasshoppers and that are formulated and packaged for homeowner use. Look for one of these insecticides listed in the active ingredients on the product label. Read the label carefully to determine if the site you wish to treat (vegetable garden, fruit trees, etc.) is listed on the label as an approved site.