Oviposition choice of milfoil weevils reared on Eurasian and northern watermilfoil for . These weevils were offered 7 aquatic plants but none oviposited on a non-watermilfoil species, indicating that weevils are specialists on watermilfoils. Regardless of original population source (Eurasian or northern), weevils reared on Eurasian highly prefer it, whereas weevils reared on northern watermilfoil show no preference between the two watermilfoils. These weevils were progeny from two source populations: weevils from northern watermilfoil were collected from Christmas Lake which had no Eurasian, and weevils from Lake Aburn were collected from Eurasian watermilfoil. Modified from Solarz and Newman (1996).