Wind Gates Olfaction Driven Search States in Free Flight.

Area of Science:

• Animal behavior
• Neuroethology
• Sensory biology

Background:

• Organisms tracking chemical cues rely on fluid motion.
• Olfactory search strategies in wind or water currents are known, but less so in unreliable conditions.

Purpose of the Study:

• Investigate how Drosophila melanogaster adjust olfactory search strategies in the absence or unreliability of directional cues.
• Determine if flies assess ambient wind presence and direction before initiating search routines.

Main Methods:

• Developed an optogenetic paradigm for free-flying Drosophila melanogaster.
• Delivered temporally precise virtual olfactory experiences in laminar wind and still air.

Main Results:

• Flies turn upwind in laminar wind using rapid turns (∼100 ms), suggesting prior wind direction estimation.
• In still air, flies exhibit a stereotyped 'sink and circle' search pattern (∼60° turns at 3-4 Hz).
• Both conditions show immediate deceleration and rapid turns upon odor onset, consistent with active sensing.

Conclusions:

• Drosophila melanogaster actively assess wind presence and direction before deploying distinct search strategies.
• Deceleration and rapid turns serve as anemometric maneuvers for gauging wind environment properties.
• These findings offer insights into insect navigation and sensory-motor control during olfactory search.