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Mollusca, Gastropoda, Limacidae .
Description, Biology, Life Cycle, Damage, Common Names, Images
[R]Biology
- Highly polyphagous, they attack in particular beets, cereals, rapeseeds, sunflower, protein pea, fodder Graminaceae, fodder legumes, maize, carrot, witloof chicory, strawberry, tomato, lettuce, potato and tobacco.
- Slug, active from the end of summer to spring.
- The time necessary to reach maturity is about 3 to 4 months and depends on the temperature. The slug is not very sensitive to cold, unless it freezes, but is sensitive to drought. Active at night, slugs remain under cover during the day, except after rain. The maximum laying takes place in autumn and at the beginning of winter.
- Eggs: length of development: over 3 months at 5°C, 15 to 20 days at 20°C. Normal developement occurs when the soil humidity ranges between 40 to 80% and the temperature between 5 and 20°C.
[R]Damage
The slugs feed between the veins of leaves, giving them a notched or ragged (Graminaceae) appearence. They also make holes in potato tubers (*) . When the attack is severe, stems are cut and eaten, plants disappear. The most sensitive stage is seedling: crops which remain at this stage for a long time (cold, drought, presence of a covering plant) are extremely vulnerable.
Losses of seedlings are especially likely on leguminous crops in September, on graminaceaous crops in spring or autumn, and on rape in autumn. Plants should be kept under observation during the critical emergence period. Spring-sown crops are vulnerable from May to September, especially in overgrown sites; autumn-sown crops in open soils are especially vulnerable from September to March. Germinationg seeds (e.g. of cereals) are often attacked beloq ground level before sedling emergence.
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.
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