Exploring the potential for control of Eurasian watermilfoil by the milfoil weevil in Christina Lake, British Columbia

Thumbnail Image
Frew, Cara Patricia
University of Lethbridge. Faculty of Arts and Science
Journal Title
Journal ISSN
Volume Title
Lethbridge, Alta : University of Lethbridge, Dept. of Geography
Aquatic invasive plants present a growing risk to the environment and the economy. One of the most problematic invasive plants found in North American waterbodies is Eurasian watermilfoil, Myriophyllum spicatum. Eurasian watermilfoil was inadvertently introduced into Christina Lake, British Columbia, Canada, in the early 1980’s. Physical control methods have been utilized since the plant was first identified in the Lake, but regular intensive management is required to meet control objectives. Variable success has been reported in Ontario lakes and waterbodies in the United States using the milfoil weevil, Euhrychiopsis lecontei as a biological control agent. Field sampling in Christina Lake indicated that the milfoil weevil is not currently present, or is present at numbers below detection. As an introductory stage of a potential biological control program, a Christina Lake-specific simulation model was developed to evaluate the expected response of milfoil growth to different weevil augmentation scenarios. Results of the model indicate that control of the sites most impacted by Eurasian watermilfoil could be achieved with a weevil augmentation rate of one weevil per square metre.
aquatic invasive plants , biological controls , Euhrychiopsis lecontei , invertebrate herbivores , milfoil specialist , Myriophyllum spicatum