Fall Armyworm

Spodoptera frugiperda

The Fall Armyworm is a lawn-damaging insect that can be found attacking Bermudagrass, Creeping Bentgrass, Ryegrasses and all Fescues. This lawn pest, also known as Spodoptera frugiperda, inhabits much of the United States east of the Rocky Mountains.

Identify

Crown & Thatch

An adult Fall Armyworm is best described as a dull-colored, medium-sized moth. The front wings of the males are dark gray and mottled with light and dark markings, and they feature a white splotch near the tip. The front wings of the females are more uniform. The mature larvae of these lawn pests are segmented caterpillars with distinct stripes: a faint line down the middle of the back and two black lines along the sides. Each segment also has four distinct spots. The larvae heads have a distinct, Y-shaped mark that is inverted and white to yellow in color. Fall Armyworm damage in lawns produces a tattered look of partially chewed grass blades. More mature larvae will eat every part of your grass plant—right down to the crown—leaving bits of chewed leaves and piles of frass behind. This is a strong sign that you're dealing with this particular lawn-damaging pest.

Life Cycle

All stages of the Fall Armyworm's life cycle are present year-round within 100 miles of the Gulf Coast. Generally, one generation is completed for those that travel north on weather fronts, while three or more generations are completed by Fall Armyworms that remain in the southern parts of the United States. Adults will migrate north throughout the growing season; however, these lawn pests are not able to overwinter in the northern states.

Control

There are two methods for controlling Fall Armyworms that TruGreen® recommends: 1. Use professionally applied pest control designed to prevent excess lawn pest populations, which can cause damage to your lawn 2. Kill insects, grubs and other lawn pests before they have a chance to damage your lawn Proper mowing and watering techniques can also help foster a healthy lawn that's more tolerant to lawn pest attacks—plus you'll get a lawn you'll want to live on in the process.