English names: African Cotton Leaf Worm, Egyptian Cottonworm, Mediterranean Brocade Moth
Nordic names: Afrikansk bomuldsugle (DK), Krysanteemiyökkönen (FI), Egyptisk bomullsfly (SE)
Major host plants
S. littoralis is a general feeder on hosts belonging to 44 families including field crops, deciduous fruit trees, ornamentals, and many vegetables. Eight families constitute more than 50 percent of the known hosts: Leguminosae, Solanaceae, Malvaceae, Moraceae, Compositae, Gramineae, Chenopodiaceae, and Cruciferae.
On most crops, damage arises from extensive feeding by larvae, leading to complete stripping of the plants. Affected Plant Stages: flowering stage, fruiting stage, seedling stage and vegetative growing stage. Affected Plant Parts: fruits/pods and leaves.
A map can be downloaded from EPPO’s website. See instructions here.
Between 2 and 5 days after emergence, females lay 1000-2000 eggs in egg masses of 100-300 underneath leaves and covered with brown scales from the body of the mother. Fecundity is reduced by low humidity. The eggs hatch in about 4 days in warm conditions, or up to 11- 12 days in winter. Larvae develop through six instars in 15-23 days at 25-26 °C. At lower temperatures, for example on glasshouse chrysanthemums in Europe, larvae often go through an extra instar, and maturation may take up to 3 months. Pupation takes place in earthen cells in the soil and lasts about 11-13 days at 25 °C. Longevity of adults is about 4-10 days, being reduced by high temperature and low humidity. The life cycle can be completed in about 5 weeks.
Flight range of adult moths can be 1.5 km during a period of 4 h overnight, facilitating dispersion and oviposition on different hosts. Long distance dispersal occurs through eggs and larvae present on plant material, cut flowers and vegetables.
Detection and inspection
Larval sampling can occur anytime foliage is present. Skeletonized leaves provide evidence of the presence of larvae. Early instars (<3rd) are likely to be found on the underside of leaves. Eggs are laid in batches, on plants and other surfaces such as pots, benches or glasshouse structures. As the adults are nocturnal, light or pheromeone traps should be used to monitor the incidence of S. littoralis.
Pest status and importance
S. littoralis is one of the most destructive agricultural lepidopterous pests within its subtropical and tropical range. It can attack numerous economically important crops throughout the year. As for S litura, the risk for S. littoralis is its possible introduction into glasshouses in most parts of Europe, where it may damage many ornamental and vegetable crops. Although control with insecticides is possible, there have been many cases of resistance. In addition, there is no immediately available biological control method, which means that introduction of Spodoptera spp. could require insecticide treatments that might interfere with existing biological control of other pests.
Source of information
See further information here:
Author: Christiane Scheel
Editor: Elise T. Yamamoto Buch