We have been seeing a large number of soybean loopers in area peanut fields. I have found up to 20 loopers per foot in some fields. In other fields we are finding very few caterpillars in total. Many of our fields are being sprayed with broad spectrum pyrethroid insecticides as leafhoppers build and are turning the peanut leaves yellow. This is reducing levels of beneficial insects and allowing looper populations to build rapidly. In many cases I am finding small caterpillars less than 1/2″ long, which can be difficult to identify. To my knowledge, soybean loopers are the only caterpillar we contend with in peanuts which have three pairs of prolegs. All of our caterpillar pests will have a pair of anal prolegs on their last body segment. The looper will have two additional pairs on the tail end of their body on segments 5 and 6. Other caterpillar pests will have three or four pairs in addition to the pair of anal prolegs. The included picture I took this week shows these 3 pairs of prolegs. The looper is also easily identified by the way it compresses the body or “loops” when it walks. Although other caterpillars may also loop in this manner, so it’s not an obvious method of identification. Be sure to check area peanut and soybean fields to assess need for treatments.