Context-dependent coordination of movement inTribolium castaneumlarvae

Abstract

AbstractStored product insect pests, likeTribolium castaneumbeetles, cause 20% of postharvest loss. However, how their nervous systems coordinate adaptive movements for successful infestation is unknown. Here, we assess howTriboliumlarvae locomote over different substrates and analyze their gait kinematics across speeds. Unlike many hexapods, larvae employ a bilaterally symmetric, posterior-to-anterior wave gait during fast locomotion. During slow locomotion, thoracic intrasegmental coordination is disrupted, whilst intersegmental coordination is preserved. Additionally, terminal abdominal structures (pygopods) support challenging locomotion, such as climbing overhangs. The onset of pygopod engagement coincides with leg swing initiation, suggesting a stabilizing role. Surgically severing the connective between thoracic and abdominal ganglia impaired pygopod engagement and impeded flat-surface locomotion, climbing, and tunnelling without interrupting leg kinematics. These results suggest that thoracic-abdominal coordination underlies effective movement, and gait/limb recruitment is context-dependent. Our work provides the first kinematic analysis ofTriboliumlarval locomotion and insights into its neural control.