IDENTIFICATION AND HABITAT CHARACTERIZATION OF MOSQUITOES IN IFEDORE LOCAL GOVERNMENT AREA, ONDO STATE, NIGERIA.

Abstract

Mosquitoes are dipterans which have been incriminated in the transmission of diseases such as malaria, yellow fever, dengue fever and elephantiasis. Of these diseases, malaria ranks as the most important, as it is the most prevalent mosquito borne disease, and currently a global scourge. Hitherto, there is a dearth of information on species diversity of these vectors in Ifedore Local Government Area of Ondo state. Thirty-six sampling sites were chosen from 6 towns within the study area and each was characterized for physicochemical parameters which, included conductivity, water temperature, Dissolved oxygen (DO), and pH. Environmental variables studied include turbidity, vegetation, bottom substrate, habitat type and canopy coverage. Larvae were collected from each site using dippers and reared in the laboratory until adults emerged. The adult mosquitoes were identified using morphological keys and standard molecular procedure using polymerase chain reaction (PCR). A one way analysis of variance (ANOVA) was employed to test for significant difference in the occurrence of anopheline, aedes and culicine larvae in the different breeding sites and also to test for differences in the habitat type distribution for each species. Correlation analysis showed the relationship between the environmental variables and the occurrence of larvae in the habitats sampled. A total of 2,357 mosquito larvae were collected (2,340 culicine, 6 anopheline and 11 aedes). There was no significant difference in the occurrence of the anopheline and aedes larvae, but there was a significant difference between the culicine larvae and the rest (anopheline and aedes) (p-value < 0.05). This study also reveal that dissolved oxygen (DO) range of 4.19 to 4.37 mg/L and conductivity value of 150.67 to 428μs across all the study areas in Ifedore local Government areas indicate the different levels of pollution in the habitats sampled and an indication that the species colonizing these areas had to be both tolerant of salt, as well as pollution, to be able to survive. The result obtained in this study revealed that larvae of Anopheles mosquitoes were sampled in habitats with low turbidity. This study concludes that conductivity, water temperature, and pH are important factors in breeding sites of mosquitoes. Therefore, this information can thus be incorporated into relevant mosquito control schemes in these localities.