SEASONAL DISTRIBUTION AND DIVERSITY OF MOSQUITO SPECIESIN A RAINFOREST COMMUNITY OF SOUTHEAST NIGERIA

Abstract

Mosquitoes are important vector of parasitic diseases. This study was conducted in Awka South LGA, Anambra State, between October 2017 and September 2018to determine the effects of rainfall, temperature, and relative humidity on mosquito species abundance and diversity. Outdoor and indoor adult mosquitoes were collected using the Centers for Disease Control light traps and pyrethrum spray catch methods, respectively. Line graphs were used to show the response of monthly rainfall, temperature, and relative humidity to the abundance of mosquito population. Pearson correlation were used to determine the relationships between rainfall, temperature, relative humidity, and the abundance of the adult mosquitoes. Shannon-Wiener diversity index and Simpson’s dominance indices was calculated for all mosquito species collected. Seven mosquito species, composed of 2,663 adult mosquitoes were collected. Anopheles gambiae, An. funestus, Aedes aegypti, Ae. albopictus and Culex quinquefasciatus were collected both indoors and outdoors while C. annulioris and Eretmapodites chrysogaster were collected outdoors. At the onset of wet season, adult mosquito population increased rapidly from 279 in April to507 September when the temperature was least at 26.0ºC with outdoor relative humidity of 90%.Adult mosquito population was positively and strongly correlated with rainfall (r=0.897) and relative humidity (r=0.700) but negatively correlated with temperature (r=-0.775).Culex quinquefasciatus had the highest Shannon-Wiener diversity index(0.107), and Simpson’s dominance index(0.495). Rainfall, temperature, and relative humidity patterns influenced the abundance of mosquitoes and should be considered during control interventions.

Keywords

• mosquitoes
• abundance
• dominance
• diversity
• climatic factors
• correlation