By Harold Watters, Ohio State University Extension agronomist
With the slow growth, no growth or no emergence of the corn and soybean crop through the month of May, insects in many cases have been able to keep up with crop progress. I like to use a calendar of pests from the Corn, Soybean, Wheat and Forages Field Guide as a starting point to know what and when to watch for pest problems.
The scouting calendar is based on an average year. As you can see for both corn and soybeans we typically have some time to go before we are beyond the threat of insect pests. Pests we have seen in May have been a few slugs, some flea beetle, and a few chewing caterpillars — last year we saw a lot more. We have European corn borer and corn rootworm as well as some anticipated bean leaf beetle to scout for in June. This year we will again scout for emerging pests — western bean cutworm and then late season watch for stinkbugs. Consult the tables and walk your fields, don’t be content with just a windshield survey.
Even though many are now thinking that drones, aerial photography or maybe even satellites may take the place of scouting, it ain’t so. You still must go to the field and look. Those tools may help pinpoint an area of greatest concern, but you still have to go to the field and get out of the truck, and walk to that point — but I also suggest you walk a random pattern of the whole field as some small creature may be lurking where you don’t expect. Our OSU/PennState Corn, Soybean, Wheat and Forages Field Guide is a great tool to diagnose in-season problems — not just insects but nutrient deficiencies too. Get this at your local Extension office or at the OSU Extension Publications store: https://extensionpubs.osu.edu/corn-soybean-wheat-and-forages-field-guide/, also available as a digital version that I carry on my smartphone.