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Insecta, Coleoptera, Chrysomelidae .
Description, Biology, Life Cycle, Damage, Common Names, Images
[R]Biology
Host plants mainly include cereals, especially wheat, barley, rye, oats and sometimes maize. Other Gramineae, e.g. rye-grass are also infested.
- Number of eggs produced: 100, 300 at the very maximum.
- Duration of egg development: about 8-10 days.
- Duration of pupation: about 2 weeks.
- The whole developmental period lasts about 40 days.
[R]Life Cycle
- There is 1 generation per year (occasionally 2 in the South and South-East of Europe owing to weather conditions).
Adults overwinter in plant debris in the soil. After leaving their shelter in the spring, they feed on wild Gramineae and, in June, young wheat.
- From mid-May, eggs are deposited in rows on the upper side of leaves. Larvae infest winter wheat from the ear emergence period to the end of milky ripeness. In dry weather, ear emergence may be prevented and growth hampered.
- Pupation takes place in a cocoon situated 3-5 cm in the soil. After hatching in late July, young adults infest late wheat fields or wild Gramineae, taking cover in late October.
- High temperatures in spring and summer favour egg-laying and induce a rise in population numbers. However, temperatures below 16 or 17°C in May-June and heavy rainfall lead to a high mortality of larvae and pupae.
[R]Damage
- Spring maturation feeding by adults cause characteristic 'windowing' of the leaves. Larvae also cause such depredations on the upper surface of cereal leaves (*) . Young adults feed mainly on wild Gramineae, larvae feeding mainly on the flag leaves of summer cereals and sometimes causing severe damage, with a reduction in yield of up to 60%.
- Oulema melanopa is a vector of certain viruses affecting Gramineae.
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.
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