From mating to sperm storage: density-dependent plasticity in pre- and post-copulatory shared mating traits

Area of Science:

• Behavioral Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Mating interactions involve traits influenced by both sexes, but individual sex control remains debated.
• Shared mating traits evolve under intersexual constraints and behavioral plasticity.

Purpose of the Study:

• To determine male vs. female control over shared mating traits.
• To investigate how developmental environments of both sexes interact to shape mating outcomes.
• To partition environmental effects on mating traits between sexes.

Main Methods:

• Utilized a fully factorial mating design with banded crickets (Gryllodes sigillatus).
• Manipulated same-sex rearing density (high vs. low) for both males and females.
• Assessed pre- and post-copulatory mating traits.

Main Results:

• Female developmental density affected mating latency; low-density females showed longer latencies, indicating female control and mate choice.
• Male developmental density influenced sperm transfer and storage; high-density males transferred more sperm, suggesting adaptation to sperm competition.
• Copulation duration correlated with female body mass, not density, suggesting partner quality influence.

Conclusions:

• Developmental context significantly influences sex-specific contributions to shared mating traits.
• Female density impacts mate choice (latency), while male density affects reproductive investment (sperm transfer).
• Understanding sex-specific environmental effects is crucial for studying the evolution of mating behaviors.