Armyworm
Armyworm is a noctuid moth larvae that travels in groups, destroying grass and grain. Also known as Pseudaletia unipuncta, a moth. Mainly found in the USA east of the Rocky Mountains.Description--The young larvae are pale green
--Older larvae become pale green brown to a black
--Movement is by arching their body into a loop while they crawl
--The western yellowstriped worm have a black color with orange and yellow stripes on the side of their bodies.
--Most will reach a length of 2 inches (5 cm).
--They are classified in the phylum Arthropoda, class Insecta, order Lepidoptera, family Noctuidae.
--The moth is grayish brown with a white spot on each fore wing. Damage CausedLarvae cause damage by eating leaves. Entire leaves may be consumed or the damage may consist of notches chewed out of the leaves giving them a tattered look. Damage may occur when larvae hatch from eggs laid in the cereal crop When many of these worms move in hordes, they travel at night and devouring grasses, young grains, and some leguminous crops.There are usually two generations in a year, the larvae hatching from eggs in late spring and again in late summer.The army worms are especially damaging in the second generation, which occurs when corn and wheat are maturing. Biological ControlThe worms are attacked by a parasitic wasp, Hyposoter species.
- Parasitized worms can be identified by pulling the larvae apart and looking for the green parasite larvae that pop out.
- Hyposoter is usually not active in early spring when cereals may be attacked by these worms but it should be looked for. Virus diseases of the armyworms may also be important natural control agents. Diseased caterpillars first appear yellowish and limp, and after death hang from plants as shapeless, dark tubes from which the disintegrated body contents ooze. Organically Acceptable MethodsBacillus thuringiensis in biological and cultural controls sprays. Cultural Control To control larvae from moving into the cereal crop from an adjacent crop, plow a deep, wide ditch between the two fields and keep it filled with water until the migration stops. Control methods include the digging of ditches and holes as traps. From Armyworm to Organic Pest Remedies
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