Adult: forewing variably brown to pale yellowish-orange, lighter grayish in lower half (along inner margin); surface sprinkled with dark brown scales; dark gray line from base to middle of wing, plus small dark patch closer to outer margin; faint oblique line from middle of wing to apex; terminal line with 4-5 dark dots; fringe checkered dark gray and white; hindwing broader than forewing, light brown to pale grayish-white; fringe whitish; [see pinned image
by C.D. Bird]
Larva: body pinkish-white to yellowish to light brown, often with paired dorsal and lateral spots on each abdominal segment; head yellowish-brown, brown, or black
all of United States and southern Canada
lawns, grassy areas; adults may fly low over lawns during the day, but are primarily nocturnal and attracted to light
adults fly from May to October
larvae feed on grasses (Poaceae)
sod webworms overwinter as young larvae a few centimeters below soil line among roots of weeds and grasses in silk-lined tubes; in early spring, larvae feed on upper root systems, stems, and blades of grass; they build protective silken webs, usually on steep slopes and in sunny areas, where they feed and develop; pupation occurs in May in underground cocoons made of silk, bits of plants, and soil; adults emerge about two weeks later, are erratic and weak flyers, live only a few days, and feed solely on dew; they rest in the grass or sometimes fly low over the ground during the day, but are primarily nocturnal, becoming active at dusk.
Eggs are deposited indiscriminately over the grass, and hatch in 7-10 days; the most severe damage to turf occurs in July and August when the grass is not growing rapidly; during this hot weather, larvae feed at night or on cloudy days; most species complete 2 or 3 generations per year, with approximately 6 weeks elapsing between egg deposition and adult emergence.
[adapted from text by North Carolina State U.]
pinned adult image
by C.D. Bird, plus description, distribution, flight season, biology, common name reference [Greater Sod Webmworm] (Strickland Entomological Museum, U. of Alberta)