Biology and host specificity of Eumolpus asclepiadeus: a potential biological control agent of Vincetoxicum spp.

Eumolpus asclepiadeus is currently being evaluated as a biological control agent of Vincetoxicum in North America. Over the past three years we have studied the natural history, host specificity, and larval feeding impact of E. asclepiadeus to determine its potential to control invasive Vincetoxicum populations. Larvae feed externally on roots and can complete development in one year but two years is more common. E. asclepiadeus successfully develops and reproduces on all Vincetoxicum, but larval development was observed on six non-target taxa under no-choice conditions. In multiple-choice tests with adults, feeding and oviposition was concentrated to Vincetoxicum but some non-target damage occurred. Although we observed strong reductions in biomass of Vincetoxicum caused by E. asclepiadeus larval feeding, further host specificity testing needs to be completed before release of this species is considered.