Description, Biology, Life Cycle, Damage, Common Names, Images
- Host plants include especially sugarbeet, mangold, spinach, cabbage, rapeseed, celery, carrot, radish, carnation (Dianthus), saponin (Saponaria) as well as many weeds.
- Hatching of eggs is spread over several years. Temperature (16°C-28°C) and radicular secretions of host plants cause some of them to hatch, thread-like juveniles then penetrating the roots using their stylet. If they do not find a suitable host, they are able to survive several months in the soil.
The salivary secretions of the parasite lead to the development of giant cells in the cortical parenchyma of infested roots. These cells interrupt the circulation of the sap and cause the death of roots. New radicles subsequently form, giving rise to thick hairs.
- After 4 moults, females become oval and protrude from the root, the head remaining fixed to the plant and the body filled with eggs (*) .
- Development, from the penetration of the first-stage juvenile to egg-laying, lasts 4-8 weeks.
There are 2-3 generations per year.
In the field, affected beet plants are distributed in circular patches (*) ; the size of plants is reduced and external leaves are yellow. Roots produce numerous small radicles (*) . Yield is greatly reduced.
- Ccabbage and rape plants are small and leaves take on a pale green colour.
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.