Visual cues and wing pitch muscles enable dragonflies’ mid-air 'righting' behavior

A dragonfly’s nimble righting reflex is a complex process involving signals from their visual system and dynamic muscular control of wing pitch, according to a new study, which offers insights into the neurological and physical mechanisms that enable the insect’s adept ariel acrobatics. The study’s novel approach could be used to evaluate natural flight mechanics across species and robotic flying systems. Dragonflies – one of the most ancient insects – are highly skilled fliers. Among their repertoire of complicated flight maneuvers, dragonflies have evolved sophisticated reflexes that enable them to right themselves when falling or after being flipped upside-down during flight. The maneuvers involve engaging in complex and rapid interactions of precise body movements and sensory information, all while obeying the laws of flight. Understanding how these creatures perform such feats could shed light on the evolution of flight control strategies, however, evaluating the dynamic flight kinematics of fast-moving insects presents unique challenges. Here, Z. Jane Wang and colleagues present a series of experimental and computational methods for analyzing flight maneuvers and use these tools to describe the righting reflex in dragonflies. First, Wang et al. performed a series of experiments in which dragonflies were released from a magnetic tether from different orientations; the authors tracked their movements using high-speed video. Then, using computational modeling and 3D insect flight simulations based on their observations, Wang et al. determined that dragonflies use wing pitch asymmetry between the left and right wings to drive upright recovery. Next, to determine whether these wing movements are elicited through upstream sensory signals, the authors performed behavioral experiments – blocking the insects’ visual systems while observing their ability to perform the movements required to flip over. According to the findings, the loss of visual sensory information impaired the insect’s ability to perform mid-air righting, implying a connection between visual signals and motor reflexes.