Adults appear on L. salicaria in early spring and feed on the youngest leaves. As soon as flower buds develop, beetles move to flower spikes where they mate and feed on receptacles and ovaries. Oviposition occurs into unopened flower buds and can extend into August. A single egg is laid into a flower bud before petals are fully developed. The larvae first consume the stamens, and then usually the petals and the ovary.
Mature larvae form a pupation chamber at the bottom of the bud.
Attacked buds do not flower and are later aborted. The new generation beetles appear mainly in August and feed on the remaining green leaves of L. salicaria before overwintering in the leaf litter. Development from egg to adult takes about 1 month and there is one generation per year. Impact on host plant Adult and larval feeding causes flower-bud abortion, thus reducing the seed output of L. salicaria. Adult feeding causes bud abortion and larval feeding reduces the seed output of L. salicaria.