Genetic matching and the identification of a promising biocontrol agent validates a decision to survey natural enemies of Urena lobata in Malaysia

Abstract

Urena lobata is a major introduced pasture weed in Vanuatu where a biocontrol program to mitigate its impacts commenced in 2018. There was considerable uncertainty regarding the native range of U. lobata, although published literature, coupled with very simple climate matching suggested that Southeast Asia should be the most promising region in which to survey for natural enemies. We, therefore, conducted surveys for candidate biocontrol agents in Malaysia and conducted genetic matching to compare plants growing in Vanuatu, Malaysia, and other regions in the invaded and purportedly native range of U. lobata. Surveys in Malaysia prioritized a tingid bug Haedus vicarius as a promising candidate agent for the biocontrol of U. lobata and subsequent host specificity testing confirmed it is sufficiently host specific to be released in Vanuatu. Genetic matching indicated that plants growing in Malaysia are a good match to plants present in Vanuatu, validating our selection of survey sites.