Platycephala planifrons ... attacks Phragmites shoots early in the year leading to severe stunting of attacked stems by killing the growing point. Platycephala planifrons was one of the most damaging species found during surveys in Europe. Attack can cause biomass reductions of >50%. Females fly in the summer and are long lived. Eggs are laid in late summer. Larvae hatch in late summer, feed for a limited period, and overwinter.