Description, Biology, Life Cycle, Damage, Common Names, Images
- Wireworms are is extremely polyphagous, and feeds on roots of numerous plant species, especially in regions with a maritime and humid climate. In dryer regions, natural meadows are especially favourable for egg laying. In regions of intensive cropping, legume plants are practically the only crops in which the larvae can start their development.
- Adult: they overwinter in the ground and then emerge in spring. They rarely fly (only at night) but walk actively.
They devour the leaves of various cultivated or wild plants. The male dies shortly after mating, the female at the end of summer.
The eggs are deposited at a depth of 20 to 60 mm, singly or in clusters of 3 to 12, preferentially in humid or fresh ground. Fecundity, 150 to 200 eggs.
- Egg: embryonic development lasts 25 to 60 days depending on the site of oviposition.
- Larva: very sensitive to drought, it moves vertically in the ground depending on the humidity, the soil temperature and the season. It digs galleries and attacks the underground parts of plants (*) , with pauses in activity in summer and in winter. Larval development takes 4 years and the larva moults 8 times.
- Pupa: in an earthen cell at a depth of 40 to 60 cm. Pupation lasts 1 month.
- 1 generation every 6 years in principle.
- Larvae pupate in May of the 5th year of development. Adults are formed in summer and remain in diapause until March of the next year. They lay eggs at the end of May - beginning of June.
- Beet seedlings are destroyed, often in more or less circular patches.
- Potato tubers are attacked at maturity, revealing narrow, shallow galleries which greatly reduce their value (*) .
- Attacks on cereals are apparent following the yellowing of the central leaf (*) .
A single larva can destroy successively several plants.
- The underground parts of carrot, hop, tomato, onion, leek, chicory, lettuce, broad bean, ornamental plants or young trees can be seriously attacked.
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.