Geographic Variation in Signal Preferences in the Tropical Katydid Neoconocephalus triops

Area of Science:

• Animal communication
• Evolutionary biology
• Bioacoustics

Background:

• Communication systems rely on signal-preference matching, which can limit phenotypic variation.
• Understanding how communication systems evolve while maintaining signal-preference match is crucial.
• Geographic variation in communication provides insights into diversification mechanisms.

Purpose of the Study:

• To investigate geographic variation in female *Neoconocephalus triops* preferences for pulse rate and call structure.
• To determine how temperature influences female katydid preferences.
• To explore the role of female selectivity in the evolution of communication systems.

Main Methods:

• Behavioral experiments were conducted to assess female preferences for pulse rate and call structure.
• Preferences were tested at two ambient temperatures (20 °C and 25 °C).
• Females from Puerto Rico and Costa Rica were studied to compare geographic variation.

Main Results:

• Puerto Rican females exhibited high selectivity for pulse rate across temperatures.
• Costa Rican females showed temperature-dependent selectivity for pulse rate, being unselective at 25 °C.
• Costa Rican females preferred versed calls, while Puerto Rican females were unselective for call structure.

Conclusions:

• Geographic variation in female selectivity for pulse rate and call structure may facilitate reproductive isolation.
• Reduced selectivity in certain populations allows for necessary variation, enabling communication system evolution.
• Differences in selectivity could stem from neural constraints or varying selective pressures.