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

A young man in a gray shirt and white cap scouting a soybean field for soybean aphids.

Should I Spray for Soybean Aphids? What’s the Threshold?

Although many soybean fields are behind schedule, so are the soybean aphid populations. In many reported areas, there are hotspots within a field where a few soybean plants may be heavily infested.

A yellow beetle with a black head, and square black markings on its back standing on a soybean leaf.

2020 South Dakota Overwintering Bean Leaf Beetle Predicted Mortality

Although bean leaf beetles won’t be emerging for a while yet, it is important to be prepared for potential early season defoliation. Once soybean are planted and begin emerging, the overwintering population of bean leaf beetle adults will move into soybean fields and begin feeding on the seedlings.

An adult, brown-to-black millipede feeding on a green leaf.

Millipedes May Be Responsible for Reduced Soybean Stands in 2020

When we think of millipedes, it is usually as a nuisance pest indoors. However, there have been reports in South Dakota and neighboring states of millipedes being more than just a nuisance in 2020.

Small soybean plants that have been cut and are laying on the ground. Curled up caterpillars are present near the plants.

Scout Soybean for Black Cutworm Activity

Typically, we are concerned with black cutworm activity in corn fields. However, 2020 has been anything but a typical year and we are instead concerned with black cutworm activity in soybean fields.

County map including portions of South Dakota, Minnesota, Nebraska and Iowa

Soybean Gall Midge Adults Emerging in South Dakota

Over the weekend, a SDSU Extension collaborator reported that soybean gall midge adults had been captured in Southeastern South Dakota. These are the first adults that have been observed in South Dakota in 2020.

Small white maggot next to a brown pill shaped pupa. Both a on soil with a yellow tape measure behind them

Watch for Seedcorn Maggots in Emerging Soybean

Of all of the potential early season pests, the seedcorn maggot is rarely an issue in South Dakota. However, we have started receiving reports of soybean fields that have poor emergence or seedling stand reductions occurring.

Small, green soybean aphids on a green, soybean stem with pink flower.

Don’t Get Surprised. Start Scouting for Soybean Aphids.

Soybean aphid populations have been observed in neighboring states and in very small populations in South Dakota. It is a good reminder that soybean aphid scouting should occur throughout the growing season to prevent population outbreaks and yield loss.