Immature development time and survivorship of the dengue vectors Aedes aegypti, Aedes vittatus, and the invasive Aedes albopictus in Ghana

Invasion of Aedes albopictus mosquitoes in the West African sub-region has coincided with multiple outbreaks of dengue fever. Unfortunately, little is known about the biology and ecology of the invasive Aedes albopictus and native vectors Aedes aegypti, Aedes vittatus. This study investigated the immature development time and survivorship of Aedes aegypti, Aedes albopictus, and Aedes vittatus mosquitoes in Ghana. Larval life-tables were conducted under semi-field conditions. Larval development time, pupation rate, and survivorship were recorded daily. Larval development time from L1→L4 was not significantly different among species. The pupation rate (Ae. aegypti: 88.7 ± 6.5, Ae. albopictus: 88 ± 9.6, Ae. vittatus: 82.7 ± 5.5) did not differ significantly. Survivorship of Ae. aegypti (0.83 ± 0.06), Ae. albopictus (0.80 ± 0.05) and Ae. vittatus (0.74 ± 0.04) was not statistically different. In combined microcosms, where all three species were raised together, survivorship of Ae. vittatus was lower (0.76 ± 0.18) compared to Ae. aegypti (0.84 ± 0.21) and Ae. albopictus (0.82 ± 0.18). This study shows that the invasive dengue vector Ae. albopictus exhibits developmental time and survival rates that are close to those of the native Ae. aegypti, indicating successful adaptation to local environments. These findings suggest that, Ae. albopictus could establish, proliferate, and compete with native dengue vectors in Ghana.