Soybean Insects

Best Management Practices for Soybean Production

This is your unbiased, research-based guide to soybean production to help increase yield, reduce input costs and protect your investment.

All Soybean Insects Content

Tan grasshopper with light colored stripes on its back sitting on the soil surface.

Will Grasshoppers Be an Issue in 2021?

With much of South Dakota experiencing dry conditions this year, grasshoppers are one of the insect pests that will need to be monitored. Large grasshopper populations may cause economic loss in cash crops and reduce forage in range and pasture lands.

Soybean plants cut by cutworm caterpillars.

Dingy Cutworms Observed in South Dakota Soybean

Dingy cutworms have been reported in South Dakota soybean. Although they are not normally a major pest of soybean, dingy cutworms will often defoliate soybean leaves and can cause significant stand reductions by cutting plants.

Yellow and black beetle on green soybean leaf.

Overwintering Population of Bean Leaf Beetles Are Active In Soybean

While scouting soybeans this week, extensive defoliation caused by bean leaf beetles was observed. Although insecticide seed treatments will reduce the threat of bean leaf beetle feeding during this time of the season, soybean fields should still be scouted.

Seecorn maggot larva feeding on a seed in a field.

Seedcorn Maggot Degree Day Activity Estimates: June 3, 2021

We are currently between the second and third generation peak emergences in South Dakota. Seedcorn maggot management must be done before planting, or the populations can be avoided by not planting during times of peak emergence.

Seedcorn Maggot Degree Day Activity Estimates: May 27, 2021

In South Dakota, we have accumulated enough degree days across the state that the peak emergence of the overwintering seedcorn maggot population has passed. In most of South Dakota, we are at peak emergence of the second generation or slightly past it.