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. Immature development time, pupation rate, and survivorship were recorded daily. The development time of Ae. aegypti, Ae. albopictus and Ae. vitattus immatures was 8.8±0.93, 9.7±1.3 and 10.6±2.0 days respectively. 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 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 close to those of the native Ae. aegypti , indicating successful adaptation to local environments. These findings suggest that Ae. albopictus could establish, proliferate, and potentially displace native dengue vectors in Ghana.