Description, Biology, Life Cycle, Damage, Common Names, Images
- Host plants: Gramineae, especially wheat.
- Adult: emerging in the spring, it feeds on the tenderest leaves, rasping the surface, injecting saliva and sucking up the cell contents. The female deposits its eggs at the axil of spikelets or at the base of the lemma of an ear whilot still enclosed in its sheath. Eggs are isolated or form clusters of 3 or 4. The female migrates from one ear to the next.
- Egg: embryonic development lasts 9-10 days.
- Nymph: there are 2 instars; nymphal development lasts 23-27 days. The young nymph feeds on the lemmae and then penetrates the flower which may become sterile due to the nymph's feeding damage. When the grain has reached the milky-ripe stage, the nymph moves into the furrow of the grain and attacks the pericarp. Once it has completed its development, the nymph vacates the lemmae and falls to the ground.
- 'Pupation': there are 3 stages, 1 'pre-pupal' and 2 'pupal', lasting only a few days.
- There is 1 generation per year.
- Adults emerge in April and fly in search of wheat. Females lay eggs in the ears which are still enclosed in a sheath. Fully developed nymphs leave the ear, penetrate the soil to a depth of 30-35 cm and enter a state of diapause in early July. They spend the summer in the soil, reappearing in early October to spend the winter under thatch (*) . They show great resistance to cold. Pupation starts in the middle of March.
- Feeding on the ovaries of tender wheat leads to distortions, degenerations, grains sometimes aborting. This has considerable consequences on yield as well as on the baking quality of flour.
- Bites on hard wheat cause the formation of flecks on the grains (*) : affected areas of the pericarp turn brown and cannot be removed during processing. Pasta manufacturers refuse the semolina.
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.