Predator-released hydrocarbons repel oviposition by a mosquito

Area of Science:

• Chemical ecology
• Behavioral ecology
• Entomology

Background:

• Prey species often detect predation risk using predator-released kairomones (PRKs).
• The precise chemical composition of PRKs is largely unknown, hindering research into predator-prey dynamics and pest management.
• Mosquito larvae of *Culiseta longiareolata* are vulnerable to predation by the backswimmer *Notonecta maculata* in temporary pools.

Purpose of the Study:

• To identify the chemical cues used by *Culiseta longiareolata* to detect predation risk from *Notonecta maculata*.
• To investigate the behavioral responses of *Culiseta longiareolata* to identified chemical cues.
• To assess the potential for using identified chemicals as environmentally friendly pest control agents.

Main Methods:

• Behavioral assays were conducted using outdoor mesocosm experiments.
• Chemical analysis was performed to identify compounds released by *Notonecta maculata*.
• The repellent effects of identified compounds on ovipositing *Culiseta longiareolata* females were tested at environmentally relevant concentrations.

Main Results:

• Two hydrocarbons, n-heneicosane and n-tricosane, were identified as being released by *Notonecta maculata*.
• These identified compounds demonstrated a repellent effect on ovipositing *Culiseta longiareolata* females.
• The repellent effects of n-heneicosane and n-tricosane were found to be additive at the tested concentrations.

Conclusions:

• n-heneicosane and n-tricosane are identified as predator-released kairomones (PRKs) for *Culiseta longiareolata*.
• These PRKs can be used by female mosquitoes to avoid ovipositing in dangerous habitats.
• The additive repellent effects suggest potential for integrated pest management strategies using these specific hydrocarbons.