LIFE-HISTORY OF THE WEEVIL EUHRYCHIOPSIS-LECONTEI, A POTENTIAL BIOLOGICAL-CONTROL AGENT OF EURASIAN WATERMILFOIL

We followed weevil life history in the lab and phenology in the field. In lab cultures, weevils progressed from eggs to adults in approximat ely 30 days. Females laid an average of 1.9 eggs per day; hatching suc cess was 87%. In a Vermont lake, weevil adults and eggs were first fou nd in late May. Thereafter there was a cyclic series of peaks in weevi l stage abundance; there appeared to be three generations of weevils e ach summer in Vermont. This weevil is being evaluated as a possible ag ent of biological control.