Potential for plant-derived semiochemicals to repel spotted lanternfly (Hemiptera: Fulgoridae) from cultivated grapevines.

Spotted lanternfly (Lycorma delicatula White [Hemiptera: Fulgoridae]) is a large piercing-sucking insect, native to Asia and invasive in the United States. Since its arrival in Pennsylvania in 2014, L. delicatula has infested 16 additional states and damaged a variety of ornamental plants, trees, and fruit crops: most notably, cultivated grapevines. While available insecticides are effective at killing L. delicatula in vineyards, they require repeated applications due to constant re-infestation by the insect, leading to increased production costs and potential secondary pest outbreaks. An alternative approach would be to repel L. delicatula from vineyards, which offers a more sustainable strategy to prevent initial and subsequent infestations. By utilizing mark-release-recapture studies under semi-field conditions in 2022, we identified lavender essential oil and CNR-1 (a proprietary emulsifiable essential oil blend) as two potential repellents for L. delicatula adults in the context of grapevines. We further evaluated the response of adult L. delicatula to lavender oil and CNR-1 SPLAT polymer matrix formulations in highly infested vineyards during September 2022. Lavender oil significantly repelled L. delicatula in early September on Vitis hybrid 'Traminette' when compared with untreated and SPLAT control treatments. We also observed L. delicatula adults shift their preference to V. hybrid 'Traminette' over V. vinifera 'Syrah' in late September, which may be attributed to cultivar preference and/or difference in senescence timing. Here, we provide evidence that lavender essential oil could serve as an additional tool for managing L. delicatula in vineyards.