Adult bacterial exposure increases behavioral variation and drives higher repeatability in field crickets

Area of Science:

• Behavioral ecology
• Animal behavior
• Pathogen-host interactions

Background:

• Individual differences in behavior are crucial in behavioral ecology.
• Animal internal states, like infection status, significantly influence behavior.
• The impact of recent pathogen exposure on behavioral variation remains understudied.

Purpose of the Study:

• To investigate how exposure to the bacterium Serratia marcescens affects boldness behavior in field crickets (Gryllus integer).
• To determine the impact of pathogen exposure on both mean behavioral expression and among-individual differences in boldness.

Main Methods:

• Field crickets (Gryllus integer) were exposed to Serratia marcescens or a control.
• Behavioral assays measured boldness, including willingness to emerge and latency to become active in novel environments.
• Among-individual variation and repeatability of boldness were analyzed.

Main Results:

• Pathogen exposure did not alter the average boldness behavior.
• Bacterial exposure significantly increased among-individual variation in boldness.
• Repeatability of boldness varied, with higher repeatability in willingness to emerge but not latency to become active.

Conclusions:

• Recent pathogen exposure can profoundly influence behavioral variation and repeatability, rather than average behavior.
• Individual differences in boldness are sensitive to environmental factors like infection.
• Sham injections led to a lack of individual differences, suggesting a non-specific effect or stress response.