One pest issue that is no stranger to Iowa soybean growers is the Japanese beetle. This insect defoliates soybean plants by chewing tissue between the leaf veins, creating webbed-looking leaves. Japanese beetles can reduce yield potential by clipping silks and damaging leaf tissue and pods on soybean plants.

According to Syngenta agronomists at the Slater, IA, Grow More Experience site, Japanese beetles have been a common issue across much of Iowa this year. To protect against Japanese beetle, growers can follow 2 management steps:

1. Scout soybean fields often. Japanese beetles will primarily feed on the upper leaves, so check the top leaves for their presence or look for a web-like leaf appearance. While damage will primarily be on the upper leaves, evaluate the entire canopy for defoliation to determine the extent of the damage.
2. If beetle damage has removed 30% of the leaf area before pod set or 20% or more of the leaf area after pod set, growers can use a foliar insecticide to knock down further damage before yield loss occurs.

For Japanese beetle control, Syngenta recommends an insecticide like Endigo® ZC, which helps provide quick knockdown and extended residual control of key foliar insect pests in soybeans.

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