Age structure of mosquito vectors from boarding school dormitories in Benin City, Edo State, Nigeria

Abstract

Anopheles and Culex species, notorious vectors of malaria and lymphatic filariasis diseases respectively are known to thrive in poor third world countries. Regular monitoring of entomological indices are necessary pre-requisites for instituting effective control against the vectors. An assessment of the parity of Anopheles gambiae and Culex quinquefasciatus mosquitoes and their relationships with temperature, relative humidity, rainfall and malaria cases was carried out in school dormitories in Egor, Oredo and Ikpoba Okha Local Government Areas (LGAs) of Benin City, Edo State. Resting adult mosquitoes were collected from randomly selected school dormitories using sweep net and mechanical aspirator between 08:00 and 11:00 hours, twice every month for 6 months. Collected mosquitoes were identified and classified as being freshly fed and unfed using relevant published keys. A total of 283 female Cx. quinquefasciatus (n = 265; 93.6 %) and An. gambiae (n = 18; 6.4 %) were dissected and examined for parity. There was significant difference (p<0.05) between total parous and nulliparous rates of An. gambiae in all the LGAs it occurred and also for Cx. quinquefasciatus, except in Ikpoba Okha (p>0.05). Variation in the monthly parous rates of the study mosquitoes in all their LGAs of incidence were not significant (p>0.05). Although, no significant association existed between parous rate of study mosquitoes and weather conditions (p>0.05), parous An. gambiae and treated malaria cases related highly significantly (p<0.01). Results from this study emphasize the need for establishment of effective control against mosquito vectors within and around human dwellings.