Jatropha gossypiifolia L.–bellyache bush

Abstract

The shrub Jatropha gossypiifolia L. (Euphorbiaceae) is an invasive and poisonous weed growing in the dry tropics of northern Australia. It has been a target for biological control in Australia since 1996, with a hiatus in the work from 2003 until 2007. Jatropha gossypiifolia is now cultivated and invasive in many tropical countries in Asia, Africa and the Pacific. In the Americas, the current geographic range is from USA to Argentina but the native range is probably restricted to the countries around the Caribbean Sea. The plant shows little genetic structuring, with limited genetic differentiation occurring across the native range in the Americas, probably a result of having been moved around by humans. In the search for biocontrol agents against J. gossypiifolia, we made over 500 collections in approximately 270 locations in 14 countries. A total of 272 probable herbivore species were collected, however most of these were rare; only 73 species were collected more than twice. Testing has been conducted on several of these species either in Mexico or in Australian quarantine. We document the significant effort invested in potential agents that led to rejection of those species and summarize the work leading to the release of Agonosoma trilineatum which unfortunately has not established. We also discuss five species, including one fungal pathogen, that are still possible, albeit challenging, candidates.