5 Major Soybean Insects: Identify Common Soybean Pests

Soybean invertebrate pests were responsible for reducing soybean bushels by 1.4% according to Crop Protection Network’s 2024 survey of 19 soybean producing states.¹

The primary production-limiting insect pests can vary from year to year in response to natural local environmental fluctuations. Over the past few years, the following inspect pests have been the major culprits to watch for.

1. Stink bugs
2. Bean leaf beetle
3. Soybean aphid
4. Japanese beetle
5. Soybean gall midge

Stink bugs

(Ronald Smith, Auburn University, Bugwood.org)

Stink bugs were responsible for losses totalling over 12 million bushels in 2024.² Stink bug species vary in size and shape. Green stink bugs are the most prevalent. Other stink bugs include brown stink bugs, the one-spotted stink bug and the brown marmorated stink bug.

• Namesake foul odor is emitted when disturbed
• Five-sided shield-shaped body
• Adult green stink bugs are usually lime to bright green.
• Black stripes on green antennae
• Stink bugs lay barrel-shaped eggs that start light green and turn yellow. Eggs are laid on the underside of the leaves.³

Bean leaf beetles

(Adam Sisson, Iowa State University, Bugwood.org)

Bean leaf beetle damage can lead to significant yield losses totalling over 2 million bushels lost annually.⁴

They also pose a threat through their ability to transmit bean pod mottle virus (BPMV), causing “green stem” syndrome and reduced seed quality/size.

Adult bean leaf beetle features:

• Approximately ¼ inch long.
• Usually yellow, tan or red in color
• Have a dark triangle behind their head.
• Frequently has two black spots on each of its wing covers and a band of black around the edge of those covers.⁵

Early season bean leaf beetle management can help mitigate yield loss.

Soybean aphids

(Adam Sisson, Iowa State University, Bugwood.org)

The soybean aphid is another destructive soybean pest in the Midwest, responsible for over 500,000 bushels lost in 2024.⁶

Soybean aphid features:

• Tiny, about 1/16 inch long
• Bright, translucent yellow-green
• Six-legged
• Pear-shaped
• Distinguishable from similar-looking insects by two small, dark tube-like structures called cornicles that protrude from their backsides and are sometimes called “tailpipes” ⁷

Japanese beetle

(Ziggy1)

Japanese beetle wreak havoc in soybean crops to the tune of 500,000 bushels lost in 2024.⁸

Japanese beetle features:

• Adults are 1/2 inch long
• Metallic green bodies with bronze forewings that don’t quite cover the end of the abdomen.
• Bulbous tips on each antenna.
• Six tufts of white hair on each side of the abdomen.
• Males have large spikes on the front tibia while females have spoon-like paddles.
• Japanese beetle larva is easily confused with May/June beetle and masked chafer grubs.⁹

Soybean gall midge

(Adam Sisson, Iowa State University, Bugwood.org)

Soybean gall midge larvae can cause localized yield losses of up 100% along field edges and up to 50% in heavily infested fields.¹⁰

Soybean gall midge features:

• Larvae begin as tiny, legless white maggots
• Maggots turn bright orange as they mature
• Adults are ¼-inch, mosquito-like flies
• Flies have mottled wings, orange abdomens and black-and-white banded legs ¹¹

Soybean insect identification is key to control

Every crop and every season brings new challenges, and our battle with pests can be one of farming’s biggest sources of frustration. If you’ve encountered pests or pest-related damage in your soybeans and would like to discuss options and strategies, experts are available to help you make your decisions. Reach out to your seed retailer, a nearby extension office agent or a seed company professional like your regional BASF representative.

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Endnotes

1. Musser, Fred, et al. “Soybean Invertebrate Loss Estimates from the United States — 2024.” Crop Protection Network, 3 Sept. 2025, cropprotectionnetwork.org/publications/soybean-invertebrate-loss-estimates-from-the-united-states-2024. Accessed 28 May 2026.
2. Musser, Fred, et al. “Soybean Invertebrate Loss Estimates from the United States — 2024.”
3. Geist, Linda. “Watch for stink bugs in crops in 2026.” University of Missouri Extension, 21 Jan. 2026, extension.missouri.edu/news/watch-for-stink-bugs-in-crops-in-2026. Accessed 28 May 2026.
4. Musser, Fred, et al. “Soybean Invertebrate Loss Estimates from the United States — 2024.”
5. “Bean Leaf Beetles (Soybean).” Purdue University - College of Agriculture, 21 May 2026, ag.purdue.edu/department/entm/extension/field-crops-ipm/soybean/bean-leaf-beetles.html. Accessed 28 May 2026.
6. Musser, Fred, et al. “Soybean Invertebrate Loss Estimates from the United States — 2024.”
7. Dean, Ashley, and Erin Hodgson. “Soybean Aphid.” Integrated Crop Management, Iowa State University, 1 May 2022, crops.extension.iastate.edu/encyclopedia/soybean-aphid. Accessed 28 May 2026.
8. Musser, Fred, et al. “Soybean Invertebrate Loss Estimates from the United States — 2024.”
9. “Japanese Beetles (Soybean).” Purdue University - College of Agriculture, 29 July 2025, ag.purdue.edu/department/entm/extension/field-crops-ipm/soybean/japanese-beetles.html. Accessed 28 May 2026.
10. Brooks, Rhonda. “Soybean Gall Midge Emerges As Top-Tier Threat.” AgWeb, 11 May 2026, www.agweb.com/news/crops/soybeans/soybean-gall-midge-emerges-top-tier-threat. Accessed 28 May 2026.
11. McMechan, Justin, and Erin Hodgson. “Soybean Gall Midge in Soybean.” Crop Protection Network, 2026, cropprotectionnetwork.org/encyclopedia/soybean-gall-midge-in-soybean. Accessed 28 May 2026.