Studies on the ecological adaptation of the mosquito aedes aegypti (diptera-culicidae) to urbanization, Dar es salaam

A twelve-month seasonal abundance pattern of the mosquito Aedes aegypti (Diptera-Culicidae) was studied using larvitraps (old tyres, vegetations, outdoor water storage containers and flower pots) in the four sampling sites namely, Vingunguti, Julius Nyerere International Airport (JNIA), Mbagala and Mkuranga (Vikindu). The aim was to investigate the ecological adaptation of the mosquito Ae. aegypti in response to increased urbanization in and around Dar es Salaam. Results from this study are compared to those from previous studies carried out in the same sites from 1968 to 1970s under the auspices of the East Africa Aedes Research Unit (EAARU). Human population size and buildings per unit area were used to quantify the level of urbanization between sites. Aedes aegypti mosquitoes were active during both dry and rainy seasons. Pearson’s correlation coefficient between the amount of rainfall and the abundance of Ae. aegypti mosquitoes for each site and for a particular breeding habitat revealed no significant correlation. There was no significant difference in the Abundance of Ae. aegypti between the rainy and dry season, (F= 0.08, P=0.92). Five genera of mosquitoes, Aedes, Culex, Mansonia, Anopheles, and Toxorhynchites were collected. Aedes aegypti was the dominant species (F=23.07, P<0.001) being abundant in old tyres ovi-traps (P=0.0045, t=2.878,) in both seasons than in other larvi-traps. There was a significant difference in the Ae. aegypti mosquito abundance in the four sites studied (F=3.804, P=0.005) indicative of the species’ adaptive capacity to breed in the constantly changing environment. Currently, in Dar es Salaam, the habitats have been altered into buildings and other developmental projects due to increase in urbanization level, these favour the breeding and proliferation of Ae. aegypti mosquitoes.