- Fruits: grapes
- Pest Management: chemical control
Lycorma delicatula, spotted lanternfly (SLF), is an invasive plant hopper from Asia and a major pest to the agricultural and forestry industries in the Mid-Atlantic region that was first detected in New Jersey in 2018. It is present at over 75% of vineyards in the state, with most. SLF is a highly polyphagous species that feeds on the plant phloem of over 100 plant taxa. A key host is cultivated grape which SLF adults congregate on in late summer/early fall. Feeding on grapevines has been associated with decreased grape growth rates, overwintering ability, and reduced crop yield. An economic threshold of 10 SLF adults/vine used in South Korea has been exceeded in many New Jersey vineyards, with some experiencing pressure of 200 SLF/vine. Waves of SLF adults colonize vines for 4-8 weeks, requiring multiple insecticide applications. On average growers apply 2 to 6 insecticide sprays just for managing SLF adults during this short time. This project aims to assess the efficacy of insecticides currently used in vineyards against SLF and the in-field residual activity of each for resistance management. This builds off previous research that has identified the peak dispersal time and residence time in New Jersey grapes as well as caged insecticide trials. Results will guide grower decisions on timing insecticide applications and materials that match preharvest restrictions. Efficacy results of this study will be disseminated directly to farmers through grower conferences and Rutgers extension blog posts.
Project objectives from proposal:
- Evaluate the residual efficacy of foliar-applied insecticides in vineyards against SLF adults.
Three pyrethroids and one noenicitinoid will be tested that varying reported residual activity. One application will be made at the peak of SLF movement into vineyards. Using decease individuals and live counts on vines percent mortality will be tracked over the course of 26 days for each of the tested insecticides to identify its efficacy over time. This will help guide grower decisions for materials used within their vineyards.
- Assess SLF female physiological state during movement.
Dead individuals collected will be sexed and ranked based on the percent fat shown on the exterior of their abdomen to assess fat body accumulation over time. Females will be dissected to identify mated status over 26 days. This will allow us to equate fat body accumulation with timing of SLF movement into vineyards. There are currently no quantifiable metrics to predict exact time of movement.
- Quantify SLF feeding impact on primary bud growth.
Primary bud formation metrics will be recorded on vines exposed to SLF feeding from fall 2022 at vineyard edge and vineyard center. This will help equate vine damage with feeding density providing insight into potential SLF feeding thresholds.