Laboratory Evaluation of Synthetic Attractants for Anopheles stephensi Using High-Throughput Screening: A Step Towards Development of Mosquito Traps.

BACKGROUND

Diseases such as malaria are transmitted by Anopheles species, among which Anopheles stephensi is one of the most important malaria vectors in Iran. Reducing the transmission of mosquito-borne diseases depends on controlling the mosquito vector or minimizing human-vector contact. A promising method for control, surveillance, and monitoring involves using synthetic attractants in traps to target vectors. This study aims to determine the effective dose of octenol, isovaleric acid, lactic acid, hexanoic acid, isoamyl alcohol, myristic acid, and ammonium hydrogen bicarbonate using the high-throughput screening system (HTSS) device in the laboratory.

METHODS

After rearing An. stephensi in the insectary, High-Throughput Screening System (HTSS) assay was used to obtain the 50% and 90% effective dose (ED) of the attractive compounds. Probit analysis was used to analyze the results and prepare the regression lines of ED50 and ED90.

RESULTS

This study showed that An. stephensi had the highest absorption to isoamyl alcohol (ED50= 0.57 mL/L, ED90= 1.04 mL/L), followed by isovaleric acid (ED50= 1.96 mL/L, ED90= 3.00 mL/L), myristic acid (ED50= 24.77 g/L, ED90= 47.08 g/L), octenol (ED50= 26.64 mL/L, ED90= 54.36 mL/L) and lactic acid (ED50= 54.98 mL/L, ED90= 132.9 mL/L), while hexanoic acid (ED50= 87.50 mL/L, ED90= 244.49 mL/L) per liter and ammonium hydrogen bicarbonate (ED50= 93.84 g/L, ED90= 234.01 g/L) showed the lowest absorption rate.

CONCLUSION

Our laboratory results identified isoamyl alcohol and isovaleric acid as highly effective attractants for An. stephensi. These compounds are strong candidates for inclusion in field-deployable traps after further validation.