Armyworms
Caterpillars that can devastate a lawn in 24–48 hours by consuming grass blades in large, sweeping "armies." Most common in late summer and fall. Fall armyworms are the most damaging species in the South, while true armyworms cause problems in the North.
Armyworms are the larvae of certain moth species that migrate northward each year from Florida and the Gulf Coast. They feed on grass blades and can strip large areas of turf to the ground almost overnight.
Signs: Ragged, chewed grass blades. Brown patches that appear to spread quickly. Birds feeding intensively in an area (birds eat armyworms). Spongy feel underfoot.
Control: Act fast — armyworms cause severe damage quickly. Products containing bifenthrin, permethrin, or chlorantraniliprole are effective. Apply in early morning or evening when larvae are feeding.
Recovery: Warm-season grasses usually recover from armyworm damage. Cool-season grasses may need overseeding.
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