Spotted lanternfly nymphs use multiple self-righting behaviors during landing

Many animals use aerial righting to mitigate the risks associated with falling (e.g., predation, starvation and desication), offering inspiration for landing strategies open to biomimetic robots. Spotted lanternflies (Lycorma delicatula) (SLFs) are invasive insect pests that often fall from host plants in response to predators or abiotic factors (e.g., wind). We used high-speed video to study whether immature SLFs (nymphs) land upright more often than expected by chance, and, if so, whether they do so via active or passive mechanisms. SLF nymphs were found to adopt a stereotypic falling posture similar to that used by insects, spiders, geckos, frogs and skydivers. Live nymphs landed upright more often when they released from surfaces than when dropped artificially. The fraction landing upright was significantly higher for live SLFs than for similarly-posed dead specimens, and did not depend significantly either on orientation during release or at first impact. Significantly more SLFs reoriented to upright from other orientations on first impact using a combination of bouncing and adhesion. Videos of nymphs landing on leaves confirmed that these insects use multiple tactics to land upright on host plants.