Armyworm
Pseudaletia unipuncta (Haworth), Noctuidae, LEPIDOPTERA


DESCRIPTION

Adult -- The adult moth is pale brown to grayish-brown in color, with a wingspread of about 40 mm. There is a characteristic white spot in the center of each forewing.

Egg -- Greenish-white and spherical, the tiny eggs are laid in masses.

Larva -- The young larva is pale green. The full-grown larva, approximately 35 to 50 mm long, is distinctly striped and yellow to brownish-green in color. Like a cutworm, it may curl into a C-shaped ball when disturbed.

Pupa -- Initially reddish-brown, the pupa darkens until it is almost black.


BIOLOGY

Distribution -- Armyworms are found throughout the world; in the United States they are most common east of the Rocky Mountains.

Host Plants -- All common lawn grasses are susceptible but are less likely to be attacked than corn, timothy, millet, small grains, and some legumes.

Damage -- Varying in abundance from year to year, young armyworm caterpillars skeletonize the surface of leaf blades and the inner surface of the sheaths. Older caterpillars begin feeding from the leaf edges and consume entire leaves. Extensive feeding causes circular bare areas in lawns.

Life History -- Armyworms overwinter as partially grown, inactive larvae which resume feeding in early spring. Their habit of moving en masse from one area to another accounts for their common name. The first generation adults appear in May or June. They feed on nectar for several days, after which females begin laying eggs. Eggs are laid at night in clusters of as many as 130 between the sheath and the blade of growing grass or in other similar places. A female can lay up to 2,000 eggs which hatch in 6 to 10 days. Second-generation larvae feed for a few weeks, then enter the ground to pupate in earthen cells 5 to 8 cm deep in the soil. The duration of the larval stage depends primarily upon food and temperature but generally lasts about 4 weeks. There are at least 5 generations per year in North Carolina. Outbreaks of the armfyworm are characterized by their sudden appearance and disappearance.


COLTROL

Natural factors such as parasites and diseases usually check the armyworm population. Outbreaks of the armyworm usually occur after years of drought.

For specific chemical control, consult the state agricultural extension service recommendations.