Fallopia japonica, an increasingly intractable weed problem in the UK: Can fungi help cut through this Gordian knot?

A new approach to the management of one of the UK's alien superweeds, Japanese knotweed (Fallopia japonica), is currently being investigated. The classical biological control strategy is based on the premise that those neophytes which become invasive and problematic are depauperate in natural enemies, both coevolved and new encounter species. Surveys have confirmed the absence of any significant natural enemy pressure in the UK, and the presence of an extensive guild of specialist arthropod and fungal natural enemies in Japan. The results of these surveys and the follow-up studies in the UK with selected fungi are discussed.