Total biomass (Ash Free Dry Mass) of Eurasian watermilfoil at the end of four weeks in tanks initially stocked with 0, 6, 12 and 24 weevil adults. Weevils reduced standing stem and root biomass. Because most damage is due to stem mining, floating and sunking biomass increased but these fragments are likely not viable. A visual illustration is here. Data from Newman et al. 1996.