Gonotrophic stages of Anopheles gambiae and Culex quinquefasciatus and their relationships with climatic conditions in selected school dormitories in Benin City, Nigeria

Abstract

Mosquito-borne pathogens are transmitted mainly during blood feeding by infective female mosquito vectors. Blood meals’ digestion stages reveal necessary entomological information for retrospective assessment and future plan for vector control. This study was done to assess the blood digestion stages of Anopheles gambiae and Culex quinquefasciatus mosquitoes and their relationships with climatic conditions in school dormitories in Egor, Oredo and Ikpoba Okha Local Government Areas (LGAs) of Benin City, Edo State. Indoor mosquitoes were collected between 08:00 and 11:00 hours from randomly selected dormitories bi-monthly for 6 months, using sweep net and mechanical aspirator. Female mosquitoes were identified and grouped into various blood digestion stages using relevant keys. A total of 439 adult female mosquitoes identified as An. gambiae (n=28) and Cx. quinquefasciatus (n=411) were examined for gonotrophic status. Total gonotrophic stages of both vector species in the collective LGAs were highly significant (p<0.01). Only Cx. quinquefasciatus revealed significant variation (p<0.01) in monthly mean percentage abundance of the gonotrophic stages across the study months in the combined LGA data. Regarding each LGA, there was significant variation in monthly mean percentage abundance of Cx. quinquefasciatus gonotrophic stages across the study months (p<0.05) in Egor and Ikpoba Okha except Oredo. As for An. gambiae, no significant difference (p>0.05) was observed per LGA. Correlations between gravid Cx. quinquefasciatus vs relative humidity, unfed Cx. quinquefasciatus vs rainfall and An. gambiae vs rainfall were the only associations that correlated significantly (p<0.05). The results indicate the need for deployment of thorough and effective vector management strategy