Potential impacts of spotted lanternfly in California

To better understand the risk spotted lanternfly (SLF), Lycorma delicatula, poses to crops of importance to California agriculture, survivorship was assessed on avocado, fig, and kiwi berry. Additionally, survivorship and damage were assessed on cucumber, peach, raspberry, hops, and grapevine (Chardonnay, Riesling, and Concord). SLF density was assessed as a contributing factor to insect survivorship and severity of host plant damage on hops and grapevine. Survivorship on fig was 87% in 2020 and 68% in 2021, 95.1% in 2020 on avocado, and 93.7% in 2020 and 57.4% in 2021 on kiwi berry. Survivorship on raspberry was 52.6% in 2020 and 42.2% in 2021, with reduced shoot growth for those exposed to SLF. Peach survivorship was 41.3% in 2020 and 57.7% in 2021, with reduced fruit size, increased fruit drop, and leaf drop all linked to branch exposure to SLF. Survivorship on cucumber was 79.9%, with reduced yield on plants exposed to SLF. Survivorship on hops in 2020 was 81.8% and 59.3% in 2021. In 2020, no impact on cone quality was observed with only a slight reduction in yield. In 2021, hops vine necrosis, leaf drop, and cone drop were all observed on vines exposed to the highest densities of SLF. In grapevine, survivorship and damage was density dependent, with overall survivorship on Chardonnay of 39%, Riesling of 46.8%, and Concord of 72%. Our results indicate that many of the surveyed crops are suitable hosts for SLF, with impacts on plant quality and  reductions in yield quantity and quality.