Description, Biology, Life Cycle, Damage, Common Names, Images
- Relatively polyphagous beetle, attacks broad bean but also pea and bean.
- After hibernation, the adult flies towards the host crops, consuming the pollen and the petals. After a few days, it mates. The female lays its eggs singly on the pods.
- Egg: embryonic development lasts on average 13 days.
- Larva: once it has hatched, the 1st-instar larva enters the pod, penetrates a seed, then moults into a 2nd-instar larva. Larval growth lasts 3 months after which the larva cuts a circular operculum in the grain's wall which will enable the adult to emerge (*) , and then pupates.
- Pupa: pupation lasts 10 to 15 days.
- Univoltine beetle.
- The most precocious beetles abandon the seeds once the plants start to ripen or when crops dry in the fields, and then hibernate in various kinds of shelter; the slower-developing individuals remain in the seeds until the next spring. Activity resumes, in France, at the end of May.
The presence of beetles in the seeds of broad beans, peas or beans renders them unsuitable for consumption, reduces the germination rate of the sowings and presents a risk of re-infestation of crops. One broad bean can harbour 5 to 6 individuals.
HYPPZ on line : Species (scientific name), Pests (common names), Glossary, Crops.