The effect of weevils on Eurasian watermilfoil carbohydrate stocks in an experimental tank study (from Newman et al. 1996). By four weeks, weevil stocking densities (initial numbers stocked) resulted in a reduction in root and shoot carbohydrate stocks. This was due to a reduction in carhydrate concentration and shoot and root mass. Carbohydrate stocks are important for successful overwinter survival and spring regrowth.