Spodoptera is a genus of moths that contains 30 species worldwide. There are 10 species in North America. Larvae of this species are commonly known as armyworms. Adults are known as armyworm moths. (Nendick-Mason, 2004)

Geographic Range

Armyworm moths are nearly cosmopolitan in distribution. They are native to all continents except for Antarctica. There are 10 species of this genus present in North America. (Lafontaine and Schmidt, 2010)

Armyworm moths are found across the world. They are native to all continents except for Antarctica. There are 10 species of this genus that live in North America. (Lafontaine and Schmidt, 2010)


Armyworm moths are found in a variety of habitats, including temperate, terrestrial, and tropical. They are most common in tropical climates, but some species migrate into temperate regions during crop growing season. Armyworm moths are found in forests, grasslands, and agricultural areas. (Pogue, 1916)

Systematic and Taxonomic History

The genus of armyworm moths previously had two synonyms, Laphygma and Prodenia. (Heppner, 1998)

Armyworm moths have been called Laphygma and Prodenia in the past.

  • Synonyms
    • Laphygma
    • Prodenia

Physical Description

Armyworm moths are greyish or brownish colored. They are typically patterned. In some species of this genus, sexes are alike. In other species, sexes may be patterned differently. (Lafontaine and Schmidt, 2010; Wagner, et al., 2011)

  • Sexual Dimorphism
  • sexes alike
  • sexes colored or patterned differently


Like other members of the order Lepidoptera, armyworms undergo metamorphosis. (Heppner, 1998)


Armyworms lay eggs at night. Most species of this genus lay their eggs in a group. They reproduce sexually and use internal fertilization. (Heppner, 1998)

Armyworm moths do not exhibit parental investment. (Heppner, 1998)

  • Parental Investment
  • no parental involvement


In the warmer parts of their range, armyworm moths produce new generations every 7-8 weeks. (Heppner, 1998)


Like other moths, armyworm moths are active at night. Larvae of many species feed at night. During the day, they occupy secluded hiding places and hide underground. Adults are able to fly and glide. Some species of this genus are sedentary, while others are motile. Armyworm moths hibernate through the winter. They live in groups. (Heppner, 1998)

Communication and Perception

Armyworms use visual, tactile, and chemical methods of communication. They also detect pheromones and vibrations. They use visual, tactile, vibrations, and chemical methods of perception.

Food Habits

Most species of this genus are polyphagous. Armyworm moths eat a large variety of vegetables, grain crops, grasses, and herbs. Species of armyworm moths in the northern parts of their range have up to 30 host plants. They may eat the leaves, stems, and fruits of their host plants. (Heppner, 1998; Nendick-Mason, 2004; Pogue, 1916)

Armyworms feed on agricultural plants like onions, celery, asparagus, peanuts, peppers, watermelon, beets, cabbages, pumpkins, cotton, soybeans, carrots, lettuce, peas, blueberries, strawberries, tomatoes, and tobacco. They feed on ornamentals like magnolias and gardeninas. (Heppner, 1998)

Ecosystem Roles

Bacillus thuringienesis is a bacteria that infects armyworms and armyworm moths. Some species of armyworms are pests that destroy crops and vegetation. (Heppner, 1998)

Commensal/Parasitic Species
  • Bacillus thuringienesis

Economic Importance for Humans: Positive

Armyworm moths have no known positive economic importance to humans.

Economic Importance for Humans: Negative

Almost half of the species in this genus are considered pest species. Larvae can destroy large numbers of crops. Larval armyworms in the Old World are notably destructive. The species Spodoptera exigua is a particularly negative pest. (Heppner, 1998; Pogue, 1916)

  • Negative Impacts
  • crop pest

Other Comments

The common name armyworm comes from the behavior of the larvae. They may move in large groups from one host plant to the next. (Pogue, 1916)


Deena Hauze (author), Animal Diversity Web Staff.



Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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living in the southern part of the New World. In other words, Central and South America.

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living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.


animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature


union of egg and spermatozoan


an animal that mainly eats leaves.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


Referring to a burrowing life-style or behavior, specialized for digging or burrowing.


An animal that eats mainly plants or parts of plants.


having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.


the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

internal fertilization

fertilization takes place within the female's body


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.


makes seasonal movements between breeding and wintering grounds


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night


found in the oriental region of the world. In other words, India and southeast Asia.

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reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.


chemicals released into air or water that are detected by and responded to by other animals of the same species


remains in the same area


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


uses touch to communicate


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


Living on the ground.


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.


A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.


movements of a hard surface that are produced by animals as signals to others


uses sight to communicate


Heppner, J. 1998. Spodoptera Armyworms in Florida (Lepidoptera: Noctuidae). Entomology Circular, No. 390: 1-5. Accessed August 14, 2020 at https://www.fdacs.gov/content/download/10777/file/ent390.pdf.

Lafontaine, J., B. Schmidt. 2010. Annotated check list of the Noctuoidea (Insecta, Lepidoptera) of North America north of Mexico. ZooKeys, 40: 1-239. Accessed August 14, 2020 at http://dx.doi.org/10.3897/zookeys.40.414.

Nendick-Mason, H. 2004. "Genus Spodoptera - Armyworms" (On-line). Bug Guide. Accessed August 14, 2020 at https://bugguide.net/node/view/6018.

Pogue, M. 1916. Memoirs of the American Entomological Society. Philadelphia: American Entomological Society. Accessed August 14, 2020 at https://archive.org/details/memoirsofameric432002amer/page/n5/mode/2up.

Wagner, D., D. Schweitzer, J. Sullivan, R. Reardon. 2011. Owlet Caterpillars of Eastern North America. Princeton: Princeton University Press. Accessed August 14, 2020 at https://www.jstor.org/stable/j.ctt7s756.