Multi-year Biological Control of Black Vine Weevil, Otiorhynchus sulcatus, with Persistent Entomopathogenic Nematodes

Abstract: The black vine weevil (BVW), Otiorhynchus sulcatus Fabricius (Coleoptera: Curculionidae), has a worldwide distribution and is a serious pest of many agricultural crops with a host plant species range of 140 plants. Common economic losses occur in small fruits, including strawberries, ornamental and nursery plants, caused primarily by the root feeding larvae resulting in reduced vigor and plant death. The susceptibility of BVW to entomopathogenic nematodes (EPNs) is well established with numerous authors publishing papers using a wide array of EPN species from commercial sources and very high application rates for use as a biopesticide. The concept of using native EPN strains that are climate adapted and retain the genetic traits of phased infectivity to persist across multiple years was successfully developed and tested on a related species, Otiorhynchus ligustici, alfalfa snout beetle. In this study, a single application of climate adapted persistent EPN strains resulted in a reduction of an economically damaging BVW population in strawberries to sub-economic levels. Subsequently, the BVW population remained undetectable for four years while the EPN populations remained moderately high