Molecular Confirmation of Anopheles coluzzii as the Major Malaria Vector in Relation to Seasonal Abundance, Biting Behaviour, and Wing Development for Vectoral Capacity in Abraka, Delta State, Nigeria

Abstract

Aproper understanding of the dynamics of malaria vectors is an important tool for vector control measures and the prevention of  mosquito bites within the study area. This study was conducted to determine the species composition, biting behaviour, and abundance  of mosquitoes with respect to seasons in the sampled mosquitoes in Abraka community of Ethiope East L.G.A, Delta State, Nigeria. Adult  Anopheles mosquitoes were collected indoors and outdoors using CDC light traps for 10 months; from May 2022 to February 2023 and  the entomological indices were examined. A total of 343 mosquitoes were obtained from this study, and the difference between outdoor  and indoor mosquitoes was significant (p<0.05). The collected Anopheles mosquitoes were morphologically identified as Anopheles  gambiae sensu lato. PCR screening confirmed the presence of Anopheles coluzzii. The wing lengths of the mosquitoes obtained outdoors  were significantly (p<0.05) longer than those obtained indoors. Furthermore, biting peaks were observed between the hours of  8-9 pm and 2-3 am. The differences between the abundance of mosquitoes with time and traps were significant (F (biting = 6.10, p=  0.0028; F =20.97, p= 0.0008). Mosquitoes were more abundant in time) (trap) September (especially indoors) than in the other sampled  months, and the lowest catch was in August. The number of mosquitoes obtained in the rainy months was significantly higher (F =6.56,  p= 0.03) than that in the dry months. (seasons) Sporozoites were not found in the mosquitoes. In conclusion, the findings of this study  showed that An. coluzzii was the major malaria vector in this location. Hence, targeted outdoor mosquito control measures should be  applied before September to reduce the malaria burden in the study area.