Species Spodoptera frugiperda - Fall Armyworm Moth - Hodges#9666

9666

Fall Armyworm (larva)

Spodoptera frugiperda (J.E. Smith, 1797) (69)

Phalaena frugiperda Smith, 1797

* Phylogenetic sequence #932216.

Frugiperda: from the Latin "frugis; frux" (fruit) + "perdere" (to lose; to ruin); probably refers to the larval feeding habits, which can cause damage or loss of commercial crops.

Wingspan 25-40 mm

TL ≈ 16-19 mm (1)

Larvae to 40 mm.

Adult: sexually dimorphic - female forewing usually plain gray with brown shading and obscure lines and spots; male forewing brown with oblique yellowish line near orbicular spot that does not extend beyond vein Cu; male has vague whitish mark below reniform spot, and whitish apical patch; orbicular spot oblique and elliptical in both sexes

hindwing iridescent silvery-white with narrow dark border in both sexes.

. . . . . male . . . . . . . . . . . . female . . . .

Larva: first instar greenish with black head; second instar head orangish, and body becomes brownish with lateral white lines in second and third instars; fourth through sixth instars head reddish-brown mottled with white, and body brownish with white subdorsal and lateral lines; dark elevated spots bearing spines appear dorsally on body - 6 spots on each segment, except 4 spots on segment eight; face of mature larva marked with white inverted "Y".

some larvae are mostly green dorsally; in the green form, the dorsal elevated spots are pale rather than dark.

[adapted from description at U. of Florida "featured creatures"]

Det. Marlin E. Rice, 2014

e NA to s CA - Map (MPG)

permanent resident in southern Florida and southern Texas; adults migrate north each summer, reaching northern United States and southern Canada by August

also occurs throughout the tropics, south to Argentina.

Fields, gardens, grasslands.

Adults present all year in deep south; July to October in middle states; late August and September in far north.

Caterpillars only in late summer and fall (2)

Larvae have been reported to feed on more than 80 species of plants but prefer grasses; crops frequently damaged include alfalfa, barley, Bermuda grass, buckwheat, cotton, clover, corn, oat, millet, peanut, rice, ryegrass, sorghum, sugarbeet, sudangrass, soybean, sugarcane, timothy, tobacco, and wheat

weedy species eaten include bentgrass (Agrostis spp.), crabgrass (Digitaria spp.), Johnson Grass (Sorghum halepense), morning glory (Ipomoea spp.), nutsedge (Cyperus spp.), pigweed (Amaranthus spp.), and Sandspur (Cenchrus tribuloides)

Larvae have been reported to become cannibalistic when food is scarce Pierce. Journal of Lepidopterist Society.

Number of generations per year depends on latitude: one generation in the far north, to several in the deep south; life cycle completed in about 30 days during the summer; eggs are laid on foliage in masses of 100-200, and the female deposits a layer of grayish scales between the eggs, giving the egg mass a furry or moldy appearance; eggs hatch in 2-3 days, and larvae develop through six instars in about 2 weeks; pupation normally occurs 2-8 cm deep in the soil, and lasts 8-9 days during the summer; adult lifespan is 1-3 weeks.

Life cycle images:

egg mass on soybean leaf; eggs; larva; larva; pupa; adult

Larvae cause damage by consuming foliage. Young larvae initially consume leaf tissue from one side, leaving the opposite epidermal layer intact. By the second or third instar, larvae begin to make holes in leaves, and eat from the edge of the leaves inward.

Larvae will also burrow into the growing point (bud, whorl, etc.), destroying the growth potential of plants, or clipping the leaves. In corn, they sometimes burrow into the ear, feeding on kernels in the same manner as Corn Earworm (Helicoverpa zea), but unlike the earworm, which tends to feed down through the silk before attacking the kernels at the tip of the ear, Fall Armyworm larvae burrow through the husk on the side of the ear.

In Yellow-striped Armyworm (S. ornithogalli), oblique yellowish line extends beyond vein Cu almost to PM line, and subterminal area has large whitish patches.

Ashley, T.R., E.R. Mitchell, N.C. Leppla, and E.E. Grissell. 1980. Parasites attacking fall armyworm larvae Spodoptera frugiperda in late planted field corn. Florida Entomologist 63: 136–142. Full Text

Mitchell, E.R. 1979. Migration by Spodoptera exigua and S. frugiperda, North America style, Pp. 386-393. In: Rabb, L.R. & G.G. Kennedy (eds.). Movement of highly mobile insects: Concepts and methodology research. North Carolina State University.

Pogue, M. G., 2002. A world revision of the genus Spodoptera Guenée (Lepidoptera: Noctuidae). Memoirs Am. Ent. Soc. 43: 69

Moth Photographers Group - MPG

Featured Creatures - John Capinera, U. of Florida

Catalog of Lepidoptera of the French Antilles - Pierre Zagatti