(J.E. Smith, 1797)
The fall armyworm (Spodoptera frugiperda) is part of the order of Lepidoptera and is the larval (see caterpillar) life stage of a fall armyworm moth. It is regarded as a pest and can wreak havoc with crops if left to multiply. Its name is derived from its feeding habits. Native to the Americas, these caterpillars mainly attack maize crops. They will eat everything in an area, and once the food supply is exhausted, the entire "army" will move to the next available food source.
The larvae are a dull yellow to gray with stripes running down the length of the body. The mature caterpillar is about 1.5 to 2 inches (51 mm) in length. The fall armyworm's life cycle is completed within 30 days during summer, and 60 days during the spring and autumn seasons; during the winter seasons these caterpillars' life cycle lasts about 80 to 90 days. The armyworm's egg is dome shaped, and measures around 0.4 mm in diameter and 0.3 m in height.
It is active at a different time of year than the true army worm, outbreaks of which usually occur during the early part of the summer; the fall army worm does most damage in the late summer in the southern part of the US, and early fall in the northern regions.:50, 53
The armyworm's diet consists mainly of grasses and small-grain crops. An infestation is hard to detect, as the caterpillars migrate to new feeding areas in the cool of the night. When the caterpillars near maturity, they can lay waste to an entire crop in a few days.
In 1998, Illinois was hit hard by fall armyworms.
In early 2017, armyworms infested large swathes of corn crops across Southern Africa, devastating the livelihood of many farmers. It is thought they arrived from the Americas as armyworm eggs in imported produce. Many African countries have agreed to take urgent actions against armyworms.
- African armyworm (Spodoptera exempta) (Africa)
- Common armyworm or true armyworm (Mythimna unipuncta) (North and South America)
- Northern armyworm, Oriental armyworm or Rice ear-cutting caterpillar (Mythimna separata) (Asia)
- Kathy L. Flanders, Donald M. Ball, Patricia P. Cobb. University of Alabama and Auburn University Extension Office. August 2011. Management of Fall Armyworm in Pastures and Hayfields
- "fall armyworm, Spodoptera frugiperda (J.E. Smith)". entnemdept.ufl.edu. Retrieved 2017-02-10.
- Luginbill, Philip (February 1928). "The Fall Army Worm". Technical bulletin (U.S. Dept. of Agriculture. Bureau of Entomology) (34).
- Murúa MG et al. (2009) Natural distribution of parasitoids of larvae of the fall armyworm, Spodoptera frugiperda, in Argentina Journal of Insect Science 9(20)
- Meagher RL and Nagoshi RN (2004) Population dynamics and occurrence of Spodoptera frugiperda host strains in southern Florida Ecological Entomology 29(5): s 614–620
- Mike Gray, University of Illinois Extension Office. July 10, 1998 Fall Armyworms: Many Southern Illinois Cornfields Are Infested
- FAO Regional Office for Africa. "Southern and Eastern African countries agree on urgent actions to tackle armyworm and other crop pests and animal diseases". fao.org. United Nations FAO. Retrieved 22 February 2017.
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