Summer Weather Paves the Way for Japanese Beetles

Published on: 14:24PM Jun 23, 2011

Dr. Roy Boykin

The hot days of summer are on the horizon, and that is just the type of weather Japanese beetles like. Over the next six weeks, the threat of a Japanese beetle infestation is at its peak. So, it’s important to know your facts, scout your fields and be prepared to deal with these insect pests. 

Japanese Beetle FeedingThe Japanese beetle arrived accidentally in New Jersey in 1916, and since then has been eating its way through the Eastern and Midwestern United States. Japanese beetles are about ½ inch long and metallic green with bronze-colored wing covers. They are identifiable by the six white tufts that grow below the wing covers. Japanese beetles "skeletonize" plants by eating the leaf tissue between the veins, creating a lace-like pattern. Severely damaged leaves will brown and drop as the insects eat upper foliage and work their way down the plant. 

Researchers advise that even if the highly mobile insect pests have not made it to your fields, this is the time of year they may. According to research from The University of Kentucky, Japanese beetles appear in mid-June and live about 35 to 40 days. A single beetle will not do much damage, but groups of beetles, attracted by each other’s pheromones, can wreak havoc on soybean.    

Japanese beetle adults defoliate soybean and cause considerable yield losses. They tend to defoliate soybean flowers during the plant’s reproductive stage, which may interfere with pollination. Research by The University of Illinois shows that Japanese beetle problems are exasperated by the presence of other defoliators and can necessitate insecticide treatment. 

To prevent soybean from suffering from the Japanese beetle’s insatiable appetite, scout early and act decisively. Scout border and interior rows for defoliation in five different areas of the field. An insecticide treatment is recommended when defoliation reaches 30 percent before bloom, or 20 percent after bloom and through pod fill. Give your fields the best protection from Japanese beetles by selecting an insecticide that provides three industry-leading technologies that work together to provide fast knockdown and longer residual control, providing you with higher potential yield and profit.

Dr. Roy Boykin, Senior Technical Brand Manager, Insecticides, Syngenta Crop Protection
Roy is responsible for the technical development, positioning and product life cycle management of insecticides for all business units in the NAFTA Region. Roy received his undergraduate education at the College of Charleston with majors in biology and business and received his master’s/doctorate degrees in entomology with minors in plant pathology and crop science from North Carolina State University.