Egyptian cottonworm

Scientific name

Spodoptera littoralis (Lepidoptera: Noctuidae)

Other common names

Egyptian cotton leafworm, Mediterranean brocade

Similar species

beet armyworm Spodoptera exigua

cotton cutworm, Spodoptera litura

fall armyworm, Spodoptera frugiperda

southern armyworm, Spodoptera eridania

For definitive identification, it is necessary to dissect adult male internal parts.

Distribution

United States: not known to be established in North America but has been intercepted at U.S. ports.

Worldwide: Africa, Asia, and southern Europe.

Native to Africa and Israel.

Diagnostic characteristics

Adults

• 20 mm (0.8 in.) in length.
• Wing span is 40 mm (1.6 in.).
• Gray to brownish-red.
• Hindwings grayish-white, lacking darker veins.
• Gray margins.

Pupae

• Reddish-brown color.

Larvae

• Six larval instars
• Final instarinstar:
  immature stages (larva or nymph) of insects in between molts
  35 - 45 mm (1.4 -1.8 in.).
• Blackish-gray to dark green, eventually becoming reddish-brown as they mature.
• Dark and light longitudinal bands.
• Dorsal dorsal:
  the upper surface of an insect
  semi-lunar dark spots.

Eggs

• Eggs laid in masses of 100 - 300.
• Eggs are whitish-yellow in color usually covered in orange brown scales from the female's body.
• Eggs masses measure about 3 - 7 mm (0.12 - 0.27 in.).

Hosts

Citrus hosts

All Citrus species and their hybrids.

Non-citrus hosts

Wide host rangehost range:
the range of species that a particular organism can feed on to achieve successful growth and reproduction
. Known to feed on 87 host planthost plant:
the plant the provides sustenance for an insect
species of economical importance including:

• all cruciferous vegetables, Brassica oleracea
• alfalfa, Medicago sativa
• avocado, Persea americana
• bean, Phaseolus vulgaris
• corn, Zea mays
• cotton, Gossypium spp.
• grape, Vitis spp.
• lettuce, Lactuca sativa
• oak, Quercus spp.
• potato, Solanum tuberosum
• soybean, Glycine max
• squash, Cucurbita spp.
• sweet potato, Ipomoea batatas
• tomato, Solanum lycopersicum

Host damage

Flowers

Plant development can be disrupted due to feeding on plant growth points.

Fruits

Larvae can bore into fruits.

Leaves

Infestation usually results in defoliation. Larvae skeletonize the leaves.

Roots

Mature larvae usually hide underground during the day and feed above ground at night. In soft soil, larvae can continue to feed on the host planthost plant:
the plant the provides sustenance for an insect
roots during the day.

Biology

A female lays 1000 - 2000 eggs in her lifetime. Eggs are laid on the lower leaf surface of host plants and are covered with scales from the female's abdomenabdomen:
one of the three body segments in insects; the most posterior segment containing the heart, reproductive organs, and digestive organs
. Eggs hatch in 2 - 5 days. Larvae feed on all parts of the plant and will sometimes hide underground during the day and feed at night. Larvae drop to the ground and pupate in the soil in an earthen cocooncocoon:
the protective covering around the pupa of some insects
.

Comments

The larvae of these moths can be transported on host plants and have been found in greenhouses as far north as Sweden. These pests are usually intercepted when traveling between countries.

In Egypt, there are 7 overlapping generations per year.

References

(CABI/EPPO) European and Mediterranean Plant Protection Organization. Centre for Agricultural Bioscience International. 1997. Quarantine pests for Europe, 2nd Ed. CAB International. Wallingford, UK

Espinosa, A. and A.C. Hodges. 2009. Spodoptera littoralis. Bugwood Wiki fact sheet. (http://wiki.bugwood.org/Spodoptera_litura).

Pierce, C.M.F. 2009. Egyptian Cotton Leafworm. Indiana Cooperative Agricultural Pest Survey System. (http://extension.entm.purdue.edu/caps/pestInfo/egyptLeafworm.htm).

Authors

Weeks, J.A., A.C. Hodges, and N.C. Leppla