Fall Armyworms in Wilmington, NC: Understanding and Managing Them

Identification

Fall armyworms (Spodoptera frugiperda) are caterpillars that cause significant damage to turfgrasses. Identifying these pests early is crucial to prevent extensive damage to your lawn. Here’s what to look for:

• Head Markings: Fall armyworms have a distinctive inverted “Y” marking on their heads, making them relatively easy to identify compared to other caterpillars.
• Body Stripes: They have black stripes running along the length of their bodies, adding to their unique appearance.
• Dorsal Dots: Four black dots are present on the dorsal side of each abdominal segment, arranged in a square pattern.
• Adult Moths: The adult stage of the fall armyworm is a moth. These moths are generally gray with a noticeable white spot on their forewings.

The distinct markings of the fall armyworm caterpillar and moth can help you identify them before they cause significant damage. If you suspect an infestation, taking quick action is essential.

Life Cycle of Fall Armyworms

The life cycle of fall armyworms includes several stages, each contributing to their potential for damage:

1. Egg Stage: Females lay up to 1,000 eggs on vegetation or nearby structures. These eggs hatch within 2-10 days, making early detection crucial. The eggs are laid in clusters and often covered with a protective layer of scales.
2. Larval Stage: This is the most damaging stage. The larvae go through six instars, or growth stages, and their feeding becomes particularly destructive after the fourth instar. At this point, they consume over 93% of the foliage they will eat during their larval stage.
3. Pupation: After feeding for about 2-3 weeks, the larvae burrow into the soil to pupate. This stage lasts about 10-14 days, during which the larvae transform into moths.
4. Adult Stage: Adult moths emerge from the pupae and are ready to mate and lay eggs within a few days. This completes the life cycle in about a month, and multiple generations can occur annually, especially in warm climates like Wilmington.

Damage Caused by Fall Armyworms

Fall armyworms can cause significant damage to lawns, and early detection is key to preventing widespread destruction:

• Early Signs: The first signs of fall armyworm damage often resemble drought stress or wilting. You might notice brown patches appearing on your lawn.
• Later Stages: As the larvae continue to feed, the lawn begins to take on a scorched or scalped appearance. This is because the larvae consume the green foliage, leaving only the stems and lower leaf portions.
• Peak Activity: Damage is more evident in the morning or evening when the larvae are most active and feeding.

The extent of the damage can vary depending on the size of the infestation and how quickly it is addressed. Prompt identification and treatment are essential to mitigate the effects on your lawn.

Detecting Fall Armyworms

To detect armyworms, mix lemon-scented dish detergent with water and pour it over a section of the turf. Armyworms will surface within 10 minutes. Regular monitoring is essential to catch infestations early.

Controlling Fall Armyworms

Effective control of fall armyworms involves both biological and chemical methods:

• Biological Control: Natural predators can manage populations, but their effectiveness varies with weather conditions.
• Chemical Control: Effective insecticides include bifenthrin, Bacillus thuringiensis (B.t), cyfluthrin, cypermethrin, lambda-cyhalothrin, permethrin, spinosad, and chlorantraniliprole. Apply insecticides when larvae are small, and avoid irrigation for 24 hours post-application.

Preventing Fall Armyworm Infestations

Prevention is key to managing fall armyworms effectively:

• High-Value Turfgrass: For high-value turfgrass, apply Acelepryn G in July or August to provide season-long control. This proactive approach helps prevent infestations before they start.
• DIY Treatment: For those who prefer a do-it-yourself approach, visit a hardware store and find an insecticide labeled specifically for armyworms. Follow the directions on the label carefully. Measure your turf to determine the correct amount of product to apply. Consistent application and following instructions can significantly reduce the risk of an infestation.

Insecticide Options for Fall Armyworms

Here are some effective insecticide options:

• Bifenthrin:
  • Ferti-lome Broad Spectrum Insecticide Concentrate
  • Ortho Outdoor Insect Killer Concentrate
  • Ortho BugClear Insect Killer for Lawns & Landscapes Concentrate
  • Bifen I/T Concentrate
  • Talstar P Concentrate
• Cyfluthrin:
  • Bayer BioAdvanced 24-Hour Lawn Insect Killer RTS
  • Bayer BioAdvanced Complete Insect Killer for Soil & Turf
  • Bayer BioAdvanced Insect Killer for Lawns
• Cypermethrin:
  • GardenTech Sevin Insect Killer Concentrate
  • Gordon’s Bug-No-More Lawn & Garden Insect Control Concentrate
• Gamma-cyhalothrin:
  • Spectracide Triazicide Insect Killer for Lawns & Landscapes
• Lambda-cyhalothrin:
  • Cutter Backyard Bug Control Spray Concentrate
• Permethrin:
  • Bonide Total Pest Control Outdoor Concentrate
  • Bonide Eight Yard & Garden
• Spinosad:
  • SC Turf Ornamental Concentrate
  • Monterey Garden Insect Spray Concentrate
  • Southern Ag Conserve Naturalyte Insect Control Concentrate

Conclusion

Fall armyworms in Wilmington, NC, can cause extensive damage to your lawn if left unchecked. By understanding their life cycle, identifying early signs of damage, and employing effective detection and control methods, you can protect your turf. For expert help and tailored solutions, contact our lawn care services. Let us help you maintain a healthy, beautiful lawn free from the devastation of fall armyworms.

We offer comprehensive lawn maintenance and lawn mowing services. Additionally, our fertilization and weed control programs are designed to keep your lawn lush and green. Visit our lawn treatment page for more information.