Critter Catalog

Diversity

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)

What do they look like?

Armyworm moths are greyish or brownish colored. They normally have patterns. In some species of this genus, males and females look the same. In other species, sexes may have different patterns. (Lafontaine and Schmidt, 2010; Wagner, et al., 2011)

• Other Physical Features
• ectothermic
• heterothermic
• bilateral symmetry

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

Where do they live?

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)

• Biogeographic Regions
• nearctic
  • native
• palearctic
  • native
• oriental
  • native
• ethiopian
  • native
• neotropical
  • native
• australian
  • native

• Other Geographic Terms
• cosmopolitan

What kind of habitat do they need?

Armyworm moths are found in temperate and tropical habitats. They live on the ground. Moths and larvae of this genus are most common in tropical climates, but some species migrate into temperate regions during crop growing season. Forests, grasslands, and farmlands are their favorite places to live. (Pogue, 1916)

• These animals are found in the following types of habitat
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• savanna or grassland
• forest

• Other Habitat Features
• agricultural

How do they grow?

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

• Development - Life Cycle
• metamorphosis

How do they reproduce?

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)

• Key Reproductive Features
• iteroparous
• sexual
• fertilization
  • internal
• oviparous

Armyworm moths do not care for their young. (Heppner, 1998)

• Parental Investment
• no parental involvement

How long do they live?

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

How do they behave?

Like other moths, armyworm moths are active at night. Larvae of many species feed at night. During the day, they hide in hidden places and underground. Adults are able to fly and glide. Some species of this genus stay in one general place, while others move around large areas. Armyworm moths hibernate through the winter. They live in groups. (Heppner, 1998)

• Key Behaviors
• fossorial
• flies
• glides
• nocturnal
• motile
• migratory
• sedentary
• hibernation
• social

How do they communicate with each other?

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.

• Communication Channels
• visual
• tactile
• chemical

• Other Communication Modes
• pheromones
• vibrations

• Perception Channels
• visual
• tactile
• vibrations
• chemical

What do they eat?

Armyworm moths eat many different kinds of vegetables, grain crops, grasses, and herbs. Some species of armyworm moths 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)

• Primary Diet
• herbivore
  • folivore

What roles do they have in the ecosystem?

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

Do they cause problems?

Almost half of the species in this genus are pests. Larvae can destroy large numbers of crops. Larval armyworms in the Old World are more destructive than others. The species Spodoptera exigua is a very bad pest. (Heppner, 1998; Pogue, 1916)

• Ways that these animals might be a problem for humans
• crop pest

How do they interact with us?

Armyworm moths have no known positive economic importance to humans.

Some more information...

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

Contributors

Deena Hauze (author), Animal Diversity Web Staff.

References

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.