Psylliodes attenuata : Distribution, phenology and control of a new invasive flea beetle in hops in Eastern Canada

The flea beetle Psylliodes attenuata native to Asia and Europe was recently found in hopyards in Quebec and Ontario. Adult P. attenuata feed on emerging hop shoots and leaves in the spring, and the next generation of adults damage leaves and harvestable cones in July and August. High populations of P. attenuata were first found in 2022 in hopyards in Quebec, and populations were present in some Ontario hopyards in 2022, with increased captures in 2023. The life cycle of P. attenuata in Canada is similar to that in Europe, with adult activity beginning in mid to late April and peaking in May. Larvae are found at the base of the plant in the soil and roots in June and early July. Adults emerge in late July and feed throughout August until hops are harvested in August and early September. Sampling with sticky cards is less effective than sweep netting early in the season and shaking bines over a collecting funnel later in the season. Adults can be controlled with insecticides; in a lab assay spinetoram was the most effective 24 h after application followed by permerthrin and imidacloprid. After 48 h, spinosad and cyantraniliprole also caused high mortality.