Visual feedback influences antennal positioning in flying hawk moths

Area of Science:

• Insect neurobiology
• Sensory integration
• Mechanosensation and vision

Background:

• Insect antennae are crucial for tactile sensing, olfaction, and flight control, requiring precise positioning for sensory feedback.
• Multimodal sensory stimuli influence antennal movements, but their integration for positioning is not fully understood.
• Böhm's bristles provide essential mechanosensory input for antennal positioning in flying hawk moths.

Purpose of the Study:

• To investigate the role of visual input in antennal positioning in hawk moths.
• To compare the effects of mechanosensory and visual feedback on antennal muscle responses.
• To understand how visual information is integrated for bilateral antennal coordination during flight.

Main Methods:

• Electrophysiological recordings (electromyograms) from antennal muscles.
• Behavioral experiments using tethered flying moths with visual stimuli (translational and rotational).
• Analysis of antennal muscle responses to visual and mechanosensory stimuli.

Main Results:

• Hawk moth antennal muscles respond to bilateral visual input, in addition to mechanosensory input from Böhm's bristles.
• Visual feedback influences antennal positioning on both contralateral and ipsilateral sides, with slower response latencies (35–60 ms) compared to mechanosensory input (<10 ms).
• Visual inputs are motion-sensitive and direction-selective; contralateral antennae move more during rotational stimuli, indicating bilateral coordination.

Conclusions:

• Visual feedback contributes to slower, bilaterally coordinated antennal movements during visually guided flight maneuvers.
• Mechanosensory input from Böhm's bristles mediates rapid antennal position corrections.
• Visual feedback modulates antennal positioning set points during flight in hawk moths.