Codling moth males do not discriminate between pheromone and a pheromone/antagonist blend during upwind flight

Area of Science:

• Insect communication
• Chemical ecology
• Behavioral neuroscience

Background:

• Pheromone communication is crucial for insect reproduction.
• Pheromone antagonists prevent attraction to signals from other species.
• Closely related species may use similar pheromones, necessitating specific communication mechanisms.

Purpose of the Study:

• Investigate the effect of pheromone antagonists on codling moth (Cydia pomonella) male attraction and flight behavior.
• Determine how pheromone antagonists influence the initiation versus maintenance of upwind flight.
• Elucidate the neural basis of pheromone signal discrimination.

Main Methods:

• Behavioral assays measuring male upwind flight to pheromone and pheromone/antagonist blends.
• Observation of flight speed, convolution, and landing behavior.
• Experimental manipulation of pheromone source proximity.

Main Results:

• Pheromone antagonists significantly reduced male attraction, primarily by inhibiting the onset of upwind flight.
• Deteriorated flight behavior (slower, more convoluted) did not fully explain the attraction decrease.
• Males did not discriminate between pheromone and pheromone/antagonist blends when landing, suggesting attraction initiation is key.

Conclusions:

• Pheromone antagonists act by blocking the initiation of upwind flight, rather than solely by impairing flight execution.
• This finding highlights separate neural mechanisms controlling the initiation and maintenance of pheromone-mediated behaviors.
• Understanding these mechanisms is vital for developing effective pest management strategies targeting insect communication.