A Simple CO₂ Generating System Incorporated with CDC Light Trap for Sampling Mosquito Vectors

Area of Science:

• Entomology and Vector Control
• Chemical Engineering and Material Science

Background:

• Carbon dioxide (CO2) is a crucial attractant for mosquito and blood-feeding arthropod traps.
• Dry ice, a common CO2 source, is often inaccessible in rural and remote regions.

Purpose of the Study:

• To develop a simple, inexpensive, and continuous CO2 generation method for use with CDC light traps.
• To evaluate the efficacy of this novel CO2 generation system for sampling adult mosquitoes in field conditions.

Main Methods:

• CO2 generated via the reaction of hydrochloric acid (HCl) with limestone powder (calcium carbonate, CaCO3).
• An intravenous drip infusion set modified to control acid flow onto limestone for continuous CO2 production (approx. 55 mL/min).
• Field evaluation using CDC light traps with three setups: light trap alone, light trap with dry ice, and light trap with the limestone-acid system.

Main Results:

• The limestone-acid system collected significantly more mosquitoes (n=267) and species (9 spp.) compared to light traps alone (n=12, 6 spp.).
• While dry ice traps captured more individuals (n=1341) and species (14 spp.), the limestone-acid system captured all common vector species identified by the dry ice method.
• The system demonstrated no bias in collecting mosquitoes of different physiological ages (parous rate).

Conclusions:

• The developed CO2 generation system using limestone and acid is a reliable, simple, and cost-effective alternative to dry ice for mosquito sampling.
• This method is suitable for use in resource-limited settings and can be optimized for increased CO2 output and collection efficiency.
• The CO2 production technique has potential applications for collecting other blood-feeding arthropods.