Worm Identification and Control in Soybean

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Key Worm Pests and Impact on Crop

  • Soybean, especially in the South, can be subject to economic damage from a number of lepidopteran worm pests, such as:

For optimum control, apply an insecticide before larvae exceed economic thresholds and follow all label instructions. Your local or state extension office can provide economic thresholds, or you can use information from the Mississippi Soybean Promotion Board. This group has compiled economic thresholds for the key worm pests of soybeans from various university sources for several scouting methods.

Corn Earworm and Tobacco Budworm

  • Similar looking species, singly laid eggs.

Soybean Looper

Velvetbean Caterpillar

Beet Armyworm

  • Apply an insecticide at first sign of significant larvae in or adjacent to field edges, or before the economic threshold is exceeded.

Fall Armyworm

  • Apply an insecticide at first sign of significant larvae in or adjacent to field edges, or before the economic threshold is exceeded.

Green Cloverworm

Cabbage Looper

Southern Armyworm

Distinguishing Armyworms and Earworms Credits

True armyworm (AWM)

  • Smooth cuticle; subdued colors.

Fall armyworm (FAW)

  • Brown/gray larva with distinct tubercles along body.
  • 3 thin, white stripes down the back.
  • Distinct white inverted “Y” on head (see image below).
  • Young larvae may be difficult to distinguish from corn earworm.

Corn earworm (CEW)

  • Bright, variable colors.
  • Cuticle has “unshaven” look.
Velvetbean caterpillar adult and larva


¹ Joseph Berger, Bugwood.org

² Whitney Cranshaw, Bugwood.org

³ J. Michael Moore, University of Georgia, Bugwood.org

4 Merle Shepard, Gerald R.Carner, and P.A.C Ooi, Insects and their Natural Enemies Associated with Vegetables and Soybean in Southeast Asia, Bugwood.org

6 Whitney Cranshaw, Colorado State University, Bugwood.org

6 Eddie McGriff, University of Georgia, Bugwood.org

All images credited above are used under a "Creative Commons Attribution 3.0 License".

This article is not intended as a substitute for the product label for the product referenced herein. The product label contains important precautions, directions for use and product warranty and liability limitations that must be read before using the product. Applicators must be in possession of the product label at the time of application. Always read and follow all label directions and precautions for use when using any pesticide alone or in tank mix combinations.

The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product performance is variable and depends on many factors such as moisture and heat stress, soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary.