Mass releases of Megamelus scutellaris in south Florida for biocontrol of waterhyacinth

Waterhyacinth is one of the most problematic invasive aquatic plants in the world. Various methods are used to manage waterhyacinth invasions in Florida’s waterways including physical removal and herbicide spraying. Since the 1970s, several biological control agents have also been released, including Neochetina eichhorniae Warner (Coleoptera: Curculionidae), Neochetina bruchi Hustache (Coleoptera: Curculionidae), Niphograpta albiguttalis Warren (Lepidoptera: Crambidae), and the most recently, Megamelus scutellaris Berg (Hemiptera: Delphacidae). Megamelus scutellaris has established populations in south Florida but it does not reach high abundances and is difficult to recover in the field. In South Africa, promising results have been achieved from the inundative releases of M. scutellaris to manage waterhyacinth populations. Hence, we aim to attempt a similar strategy in south Florida. The population of M. scutellaris released in South Africa was sourced from Buenos Aires, Argentina, while the population released in south Florida was sourced from Paraguay. Through collaboration with researchers in South Africa as well as the Florida Fish and Wildlife Conservation Commision, this project will involve mass rearing and inundative releases of both the Argentinian and Paraguayan M. scutellaris populations to determine whether the methods that are successful in South Africa can be applied to help manage waterhyacinth in south Florida. Through comparing waterhyacinth surface coverage and health, as well as insect abundances at release sites, population differences can be determined and biocontrol methods improved.