Forewing asymmetries during auditory avoidance in flying locusts

Area of Science:

• Bioacoustics
• Insect flight mechanics
• Animal behavior

Background:

• Flying insects use auditory cues for navigation and predator avoidance.
• Bat echolocation calls are a significant auditory threat to flying insects.

Purpose of the Study:

• To investigate the kinematic and postural changes in locusts responding to bat-like sounds.
• To understand the neural and muscular mechanisms underlying locust flight steering maneuvers.

Main Methods:

• High-speed cinematography and videography to record locust flight responses.
• Analysis of body posture, wing kinematics, and muscle activation patterns.
• Stimulation of tethered flying locusts with bat-like auditory signals.

Main Results:

• Locusts exhibited phonotaxis (negative and positive) to bat-like sounds.
• Asymmetrical forewing depression and decreased stroke amplitude were observed during turns.
• Asymmetric muscle activation (forewing first basalar muscles) correlated with steering responses.

Conclusions:

• Forewing asymmetry and altered muscle activity are key to locust flight steering.
• These kinematic changes generate roll torques, augmenting other steering mechanisms for rapid evasion.
• The study elucidates a sophisticated sensory-motor control system for predator avoidance in locusts.