Author
Corin F Pratt
c.pratt@cabi.org
CABI
Ascot
Coauthors
Anna Tilling, CABI, Ascot, UK
Daisuke Kurose, CABI, Ascot, UK
Abstract
Myriophyllum aquaticum is a perennial aquatic herb native to South America but invasive in North America, Europe, Africa, Australasia and Asia. The plant thrives in freshwater habitats and can colonise and dominate aquatic environments, reducing biodiversity, outcompeting native flora and impeding recreation. In Great Britain (GB) the plant reproduces effectively by fragmentation alone. Plants can be spread by human activity and thrive in nutrient enriched water bodies. Control of M. aquaticum via manual and mechanical means is typically short-term, costly and can cause fragmentation and spread, with herbicide treatment in water bodies tightly regulated. In GB, research into the classical biological control of M. aquaticum was initiated in 2020, focusing firstly on Lysathia cilliersae, a leaf beetle released in South Africa in 1994 and proving an effective agent, and more recently on Listronotus marginicollis, a stem mining weevil determined to be specific in South African studies, but not released. CABI UK sourced L. cilliersae and L. marginicollis ex. Argentina via collaborators. Research into classical biocontrol of M. aquaticum for North America is run in parallel at CABI Switzerland, allowing collaboration and data sharing. Host-range and impact assessment data will be summarised, in addition to molecular research to elucidate the identity of a red-stemmed Myriophyllum species previously known only via the plant trade but found naturalised in GB and exhibiting invasive traits.
Keywords
Myriophyllum aquaticum
aquatic
Great Britain
Lysathia cilliersae
Listronotus marginicollis
Highlights
Host range assessment of Lysathia cilliersae, a leaf beetle successfully released in South Africa
Host specificity and potential impact of the stem mining weevil Listronotus marginicollis
Molecular assessment of a widely sold but potentially invasive congener of Myriophyllum aquaticum