Utilizing Metarhizium anisopliae Strain F52 for control of black vine weevil Otiorhynchus sulcatus (Fabricius) (Coleoptera:Curculionidae)

Black vine weevil (BVW), Otiorhynchus sulcatus (Fabricius), is one of the primary pests of cranberries in Washington. The larvae, present in the duff layer and soil, feed on the roots of the cranberry vines, resulting in the death of the vines. We will present efficacy data of Metarhizium anisopliae Strain F52 (containing 9.0 x 10⁸ colony forming units/gram) on black vine weevil. Field trials were conducted in Grayland, WA in 2013 and 2014 and were followed up with lab trials using treated soil from the field sites on uninfected larvae. Efficacy was evaluated based on field counts of live larvae 1 to 2 months after treatment. Our observations indicate Metarhizuim anisopliae (Met52 granular) provided consistent control of black vine weevil larvae when applied at 112 kg/ha across all timings.