Effects of host plants on spotted lanternfly (Hemiptera: Fulgoridae) nymphal survival and development.

Spotted lanternfly, Lycorma delicatula (White), is an invasive planthopper from China, which was first detected in Berks County, PA, in 2014 and has since spread to adjacent states including New Jersey in 2018. Lycorma delicatula is a polyphagous species that gregariously feeds on over 172 known hosts. We investigated development on key host plants Ailanthus altissima (Miller) (Sapindales: Simaroubaceae), Juglans nigra (L.) (Fagales: Juglandaceae), Acer rubrum (L.) (Sapindales: Sapindaceae), and Vitis vinifera (L.) (Vitales: Vitaceae) for each instar to elucidate potential host use throughout the season and target monitoring efforts. Our study indicated significant differences in survivorship and time spent in each nymphal life stage between host plants. We applied a host suitability index as a function of survivorship and development for each host plant and instar, which indicated A. altissima and J. nigra as suitable hosts for all 4 nymphal instars. Vitis vinifera was highly suitable for first and second instars but had low indices for the third and fourth instars, although suitability of V. vinifera may have varied based on variety and age of the vine. Lycorma delicatula nymphs had the lowest survivorship and longest development time on A. rubrum across all 4 life stages, despite this being a preferred oviposition host. Host had a significant effect on the morphometrics we measured within the first and second instars.

Evaluating deployment strategies for spotted lanternfly (Lycorma delicatula Hemiptera: Fulgoridae) traps.

The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), is an invasive planthopper that was first detected in the United States in Berks County, PA, in 2014, and has since spread to 13 states in the Eastern United States. This phloem-feeding pest has a broad host range, including economically important crops such as grapevine, Vitis spp. Monitoring presence and relative abundance of L. delicatula is essential to develop pest management tools. Here, we compared deployment strategies to optimize use of L. delicatula monitoring traps. Standard circle traps, sticky bands, and circle traps with replaceable bag tops were deployed at sites with either high or low populations present. Trap deployment at different heights and on different host tree species and trap sampling intervals were evaluated for standard circle traps only. Circle traps captured significantly more L. delicatula adults at low-density sites compared with other trap types in 2021, and no differences were detected at high-density sights. Traps deployed 1 m from the ground captured significantly more adults than those deployed at 0.5 m; no differences were detected for nymphs. While no significant differences in captures were found among intervals, weekly or biweekly sampling prevented specimen degradation. Although traps deployed on Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) captured significantly or numerically more L. delicatula at most sites, traps deployed on other hosts also yielded consistent captures. We were also able to alter the construction of circle trap skirts to allow for deployment on different sized tree trunks.

Characterizing location of spotted lanternfly egg masses in wooded habitat during early invasion stages.

The spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), is an invasive planthopper from Asia that is estimated to have spread 17 km/yr since it's initial detection in Pennsylvania in 2014. Lycorma delicatula is a pest to the agricultural and forestry industries in the Mid-Atlantic region of the United States, in part due to its highly polyphagous nature. Current detection relies on visual observations, unbaited traps, or eDNA surveillance in its primary hosts, including grape and hardwoods. These approaches narrow the surveillance area by concentrating on known host plants but could be further refined to narrow the search parameters from the 100+ known host plants. Because L. delicatula appears to have a strong population buildup in wooded areas, we evaluated the relationship between egg mass presence and habitat characteristics in wooded habitats adjacent to vineyards in New Jersey at six farms within the first two years of L. delicatula detection. Habitat characteristics included distance from wood edge, and presence of a critical host plant Ailanthus altissima, and presence of Vitis spp. within 4.5 m. We identified a significant relationship between egg mass presence and Vitis spp. with an 88% probability of finding an egg mass close to a wild grapevine, dropping to 9% where grapes were absent. During the early invasion stages when this research was conducted, a two-year delay from initial detection in wooded habitats to nymphal presence in the vineyard was observed.