Description, Biology, Life Cycle, Damage, Common Names, Images
This weevil feeds on wild or cultivated brassicas: cabbage, cauliflower, coleseed, turnip, radish, mustard (Sinapis), horse-radish (Armorica).
- Adult: it overwinters under lumps of earth or under plant debris and resumes its activity in spring, 20°C is the optimal flight temperature. The female lays 2 to 8 eggs in the petiole or the young stems or along the main veins of the leaves.
Average fecundity, 80 eggs.
- Egg: embryonic development lasts 5 to 8 days.
- Larva: it forms a relatively large gallery which reaches to the pith and may extend down to the roots. The larvae from a same laying use the same gallery. Larval growth lasts 3 to 6 weeks until pupation, which takes place in the ground.
- Pupation lasts 3 weeks.
- 1 annual generation.
- The young adults appear in autumn. They move about on the plants for a few days then shelter to overwinter. They resume their activity from the end of March to the beginning of April.
The attacked plants become yellow, their leaves lose their normal turgor and their development is slowed down.
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.