Factors influencing gonotrophic discordance and its impact on Aedes aegypti vectorial capacity for dengue virus

Mosquito biting behavior is a critical determinant of mosquito-borne pathogen transmission. The biting rate of Aedes aegypti, the primary vector of dengue, is often estimated as the reciprocal of gonotrophic cycle duration (1/GCD) under the assumption of one feed per cycle. However, this species frequently takes multiple blood meals within a cycle—a phenomenon called gonotrophic discordance. We quantified this behavior by marking individual mosquitoes with fluorescent powder and offering blood meals twice daily until oviposition, measuring feeding frequency, GCD, and oviposition patterns at 5 and 15 days old. To test the effect of size, larvae were individually reared under low and high food diets, producing significantly different adult sizes. To test temperature effects, additional high diet adults were assayed at elevated temperature (26ºC vs 32ºC). Mosquito biting rate (MBR) was defined as blood meals per GCD and compared to 1/GCD. An extended and global sensitivity analysis of vectorial capacity evaluated transmission impacts of both definitions of biting rate. Across treatments, MBR significantly exceeded 1/GCD, with the greatest discordance in small mosquitoes. Large mosquitoes at the same temperature showed lower discordance that increased with age. However, large mosquitoes at an elevated temperature showed discordance only in the older stage. Sensitivity analyses revealed that replacing 1/GCD with MBR increased estimated transmission potential. Our results demonstrate that age, size, and ambient temperature have different effects on gonotrophic discordance and thus biting rate. Incorporating this behavioral heterogeneity into transmission models could improve disease-risk predictions and inform more effective vector control strategies.