Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Insects associated with butternut and butternut canker in Minnesota and Wisconsin.

Abstract

Butternut, Juglans cinerea, is being killed throughout its native range in North America by the fungus Sirococcus clavigignenti-juglandacearum. In addition to rain splashed spores, it is thought that the fungus may have spread over long distances to infect widely-scattered butternut by insect vectors. In surveys conducted in Minnesota and Wisconsin during 1995-96, several insect species found in close association with diseased butternut trees, and spores of S. clavigignenti-juglandacearum, were isolated in pure culture from the bodies of some of these insects. Potential insect vectors were species in the coleopteran genera Eubulus (Curculionidae), Laemophloeus (Laemophloeidae), and Glischrochilus (Nitidulidae). Because several insect species become contaminated with fungal spores, further study is needed to determine if any of these insects might transmit the fungus to healthy trees, and thereby infect them.