Effects of Lycorma delicatula nymphal feeding and insecticide efficacy against adults in NJ grapes

Spotted lanternfly (SLF) was first documented in New Jersey in 2018 and have since established populations in every county of the state. This insect pest feeds gregariously on the phloem of over 103 documented host plants worldwide. Although SLF are polyphagous, one of their preferred hosts is known to be grape. Highest SLF presence in vineyards is seen in early spring when nymphs hatch from egg masses laid within the vineyard the previous fall and once more in mid-September when adults begin to move. New Jersey’s thriving grape industry is being threatened by this invasive plant hopper. Adult feeding in late season has be associated with decreased plant vigor, yield loss, and ability to overwinter. Insecticide application for adult stages is the primary management strategy but is complicated by continual large immigration into the vineyard for 4-8 weeks coinciding with harvest. Insecticide residual activity will be measured to identify the best management practices for vineyard managers. The need to manage nymphs is unknown because injury is not quantified. We will measure injury to vines across naturally occurring nymph densities in cultivated grape.