Get a grip: evaluating the importance of different beetle tarsal structures in landing attachment

To successfully locomote across leaf surfaces, which vary in roughness and inclination, beetles evolved tarsal structures (setae and claws) that allow attachment. Structures form a synergistic system, with adhesive setae being effective on smoother surfaces, while claws are adapted for larger asperities. Many beetles also migrate using flight, attaching to surfaces during landing. However, the role of tarsal structures in this dynamic form of attachment is far less studied. To explore this question, we separated Hippodamia convergens beetles into three groups, manipulating setae or claws in two while the final group was unmodified. We exposed groups to diverse surfaces at different inclines, inducing flight and observing landing success. Logistic regression showed that landing success was significantly lower in modified groups compared with the control, but surface type did not have a strong effect. Interestingly, the claw removal group had low success across all surfaces/inclines, highlighting the importance of this feature.