Interactions among biological control agents on water hyacinth: impacts of herbivory on the oviposition and development of Megamelus scutellaris

Multiple biological control agents have been developed and released to increase control and reduce treatment costs ofPontederia (Eichhornia) crassipesin Florida. Although two species of weevil (Neochetina eichhorniaeandNeochetina bruchi) and the planthopper (Megamelus scutellaris) utiliseP. crassipesfor feeding and reproduction, little is known about their interactions including any negative interactions that might reduce their individual or overall effectiveness in suppressing the plant.Megamelus scutellariswas provided with the choice of weevil-damaged or undamaged plants and allowed to oviposit. Plants were then monitored individually for nymph emergence to determine the plant preference for adults. There were no differences in F(1)emergence numbers among the treatments indicating that in this specific situation the potential for negative interactions betweenNeochetinaspp. andM. scutellarisis minimal. Additional studies are required to quantify the potential for other types of interactions among these biological control agents.