Context-Dependent Anti-Predator Behavior in Nymphs of the Invasive Spotted Lanternfly (Lycorma delicatula): Effects of Development, Microhabitat, and Social Environment

Abstract

Antipredator behaviors in animals often vary with developmental stage, microhabitat, and social context, yet few studies examine how these factors interact in species that undergo ontogenetic shifts in chemical defense. The spotted lanternfly (Lycorma delicatula) is an invasive planthopper whose nymphs transition from cryptically colored early instars to aposematically colored fourth instars that feed primarily on chemically defended host plants. We conducted 1460 simulated predator attacks on nymphs across four developmental stages to examine how antipredator behavior varies with instar, plant location (leaf vs. stem), host plant species, and local conspecific density. Nymphs exhibited three primary responses: hiding, sidestepping, or jumping. We found that location on the plant had the strongest effect, with nymphs on stems more likely to hide than those on leaves. Older instars were significantly less likely to hide and more likely to sidestep, particularly on stems, suggesting reduced reliance on energetically costly escape behaviors as chemical defenses accumulate. First instars were less likely to jump from their preferred host plant (tree of heaven) compared to other plant species. Higher local conspecific density reduced hiding probability, likely due to the dilution effect. These results demonstrate that antipredator strategies in L. delicatula are flexibly deployed based on developmental stage, microhabitat structure, and social context, with implications for understanding evolution of antipredator behavior in chemically protected species.

Keywords: antipredator behavior; aposematism; escape; instar; ontogenetic color change; spotted lanternfly.

Figure 1

(a) 3rd instar, (b) 4th instar and (c) adult spotted lanternfly.

Figure 2

Model coefficients and standard errors for predictors of antipredator behavior in SLF nymphs. Each point represents a model coefficient (log-odds), with horizontal error bars indicating the standard error. Predictors with positive coefficients increase the odds of the focal behavior, while negative coefficients decrease it.

Figure 3

Predicted probabilities of each antipredator behavior on (a) leaves of tree of heaven, (b) stems of tree of heaven, (c) leaves of other plants, and (d) stems of other plants.

Figure 4

Overall effect of the number of other SLF nymphs within a 10 cm radius on predicted probabilities for each antipredator behavior, averaged across all developmental stages, tree categories, and microhabitats. The shaded ribbons represent 95% confidence intervals around each prediction.