Nondestructive Sampling for Spotted Lanternfly (Hemiptera: Fulgoridae) Egg Masses in Woodlands Based on Fixed-Radius Plots

Abstract

A nondestructive sampling method was developed for Lycorma delicatula egg masses based on fixed-radius plot (100 m2) in 2020. All trees >1.0 cm DBH (diameter at breast height, 1.37 m in height) on each plot were visually inspected from the ground 4 m from the tree with binoculars. Egg masses found on trees were separated into six within-tree positions (lower trunk, middle trunk, upper trunk, first branch, second branch, above second branch) and recorded by cardinal directions, whereas those laid on shrubs/vines and stones were recorded without such separation. In total, 146 trees were inventoried at 28 plots over seven study sites (four plots per site). Egg masses were found on 19 tree species plus summer grape (Vitis aestivalis) and stone. Of the 421 total egg masses recorded, 31.1% were on Norway maple (Acer platanoides), followed by tree-of-heaven (Ailanthus altissima; 14.7%), black birch (Betula lenta; 12.6%), tuliptree (Liriodendron tulipifera; 11.9%), and American beech (Fagus grandifolia; 10.2%). Egg mass density per tree was positively correlated with tree diameter, and egg mass density per plot was positively correlated with plot basal area. Egg mass density after conversion ranged from 600 to 3,930 eggs masses/ha with no significant difference among study sites. Cardinal direction had no effect; however, significantly more egg masses were found on the first branches and upper trunks than other within-tree positions. Overall, branches were better than trunks in predicting egg mass number for the tree. The role of distance and late season adult aggregation on oviposition substrate selection are discussed.

Spatial Distribution, Seasonal Dynamics, and Sex Ratio of Lycorma delicatula (Hemiptera: Fulgoridae) Adults on Tree of Heaven

“…e small increase between late September and mid-October (Figures 4(b) and 5) could be the result of reverse migration by gravid females for oviposition as tree of heaven is one of the preferred substrates [13,29]. Information on adult movement between and within hosts during the season is needed.…”

“…e relationship between adult and egg mass spatial distribution on tree of heaven may also deserve more attention as most adults were congregated on lower and middle trunks, while most egg masses were found on the upper trunk and first order branches [29,43,44]. Gravid females must disperse within or between trees to avoid interspecific competition during oviposition.…”

“…is study was carried out at six mixed hardwood sites (0.5-1.0 ha) (Antietam, Buck Hollow, Gibraltar North, Gibraltar South, Marsh Creek, and Wertz) in southeastern Pennsylvania in 2020. See the work of Liu and Hunter [29] for site location, stand condition, infestation history, chemical control of L. delicatula, and herbicide treatment of tree of heaven at each site. Nolde Forest was excluded from this study due to complete tree mortality of tree of heaven associated with L. delicatula feeding damage at the site in the spring of 2020.…”

Oviposition selection in spotted lanternfly: impact of habitat and substrate on egg mass size and hatchability

“…(opercula) and attached whitish/yellowish pronymphal cuticles (Figure 1D) indicates hatch success (20,22). Hatch success was calculated as described before.…”

Evaluating Materials to Serve as Removable Oviposition Substrates for Lycorma delicatula (Hemiptera: Fulgoridae) Under Field Conditions

“…While this approach does generate both egg masses and nymphs, there may be a possibility of using egg masses collected from nature as a source for rearing biological control agents. High densities of egg masses have been recorded in the field (up to 75 egg masses per m 2 ) on natural host substrates (Liu 2019a; Liu & Hunter 2021). However, removal from these host substrates requires a great deal of time and careful handling (Nixon et al 2022) because egg masses become brittle as the winter season progresses, with the protective waxy coating flaking away and exposing egg masses to potential damage or dislodgement when removed from the substrate.…”