Common Names: African Cotton Leafworm, Egyptian Cotton Leafworm, Mediterranean Brocade
Latin Name: Spodoptera littoralis
Main Host(s): Extensive host plant range including ornamentals, vegetables, fruits and row crops.
Spodoptera littoralis is native to Africa, the Middle East and the Mediterranean countries of Europe. In Spain, Italy and Greece the insect can be found in numerous greenhouse crops including tomato, pepper and melon. S. littoralis is not established in the northern parts of Europe and the UK due to cooler temperatures and its quarantined pest status. However, in the northern EU countries, it can be introduced in greenhouses and nurseries with shipments of transplants and nursery stock.
The pest has a wide host range, feeding on the leaves and fruiting structures of more than 44 plant families. Popular hosts include cotton, corn, tomato, okra, onion, cabbage and cucurbits. The moths are good flyers and can disperse over a long distance in search of new/suitable host plants. In warm climates, up to 8-9 generations are possible. The pest overwinters as pupa in the soil.
The female lays from 100-300 whitish-yellow eggs in clusters covered with moth scales on the under surfaces of leaves. The eggs hatch in four days (depending on temperature) and initial larval feeding causes leaf skeletonization – an early indication of infestation. Six larval instars of Spodoptera littoralis over a three week time period occur in warm climates, with an additional larval stage and longer development times in cooler regions.
Impact & Damage
Early larval damage appears as skeletonization of leaves. Larger larvae will do extensive damage, stripping foliage and infesting plant fruiting structures. In Africa and the Middle East, field research has documented instances of chemical insecticide resistance, such as to chlorpyrifos in Turkey.
XenTari® is particularly effective against S. littoralis larvae and is widely used in Spodoptera control. This proprietary strain of Bacillus thuringiensis aizawai (ABTS-1857) contains two additional toxin proteins with very good, highly-specific activity against Spodoptera species. As with most caterpillar larvae, the earlier the treatment is made the more effective it will be since the youngest larval stages are the most susceptible. In field or greenhouse setting, an IPM/IRM program rotating or tank mixing chemical insecticides with biorational pest control products such as XenTari will give the best result.
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