Moderate attack suppresses flowering and reduces root and shoot biomass.
Heavy attack prevents flowering and kills many plants in 3-4 years. Robust plants refoliate during beetle pupation in July and are attacked by a second generation in late July-August. The beetles spread 1.6 km in 3 years, principally along water edges. Galerucella calmariensis is light tan with a dark band on the wing cover margin and triangular mark behind the head. Galerucella pusilla is light golden-brown and lacks the dark marks.