<i>Anopheles</i> species composition and some climatic factors that influence their survival and population abundance in Anambra East LGA, Anambra State, Nigeria

Abstract

Malaria parasites are transmitted in nature through the bites of female Anopheles mosquitoes. However, the vector distribution varies in time and space. This study aimed to determine the species composition, abundance and climatic factors influencing Anopheles mosquitoes in Anambra East Local Government Area of Anambra State, Nigeria from October 2016 to September 2017. Adult Anopheles mosquitoes were collected from indoor and outdoor locations using Pyrethrum Knockdown Collection (PKC) and Human Landing Catch (HLC) Methods respectively. Anopheles mosquito larvae were collected using dipping method. Morphological identification of Anopheles species was carried out using standard identification keys. Climatic data was obtained from Nigerian Meteorological Agency Office in Anambra State. A total of 8181 female Anopheles mosquitoes which comprised 4127 (50.4%) larvae and 4054 (49.6%) adults were collected (P &gt; 0.05) in the study. Four Anopheles species: An. gambiae s. l (70.1%), An. funestus group (18.2%), An. moucheti (6.3%) and An. nili (5.4%) were identified (P &lt; 0.05). In the study area, 2608 (31.9%), 3025 (37.0%) and 2548 (31.1%) Anopheles mosquitoes were collected from Aguleri, Igbariam and Nsugbe respectively; with 100% species overlap. In each selected selected town, the Simpson’s index of diversity was ~2 and Shannon-wiener diversity was ~1. Only An. gambiaes l showed varied seasonal abundance with wet season contributing 67.9% and dry season 32.1% of the overall An. gambiaes. l collection (P &lt; 0.05). The correlation between rainfall and An. gambiae s. l. abundance was significantly strong (r = 0.66; P &lt; 0.05). No significant correlation was found between Anopheles species abundance and temperature as well as relative humidity. The study revealed the preponderance of four Anopheles species: An. gambiae s. l., An. funestus, An. moucheti and An. nili; and rainfall is the only climatic factor that causes temporal change in the abundance of one of the species, An. gambiaes. l. in the study area.&#x0D; Keywords: Anopheles mosquitoes, abundance, temperature, rainfall, relative humidity

Abundance and diversity of man-biting mosquito species in the tropical rainforest belt of Southeastern Nigeria

“…Six genera of mosquitoes Aedes, Anopheles, Culex, Mansonia, Eretmapodites and Coquillettidia composed of fifteen species were observed in this study. Similar findings were recorded by some previous works on mosquito distribution and abundance in Nigeria [1,8,3,9] . This wide variety of mosquito species observed in this study could be as a result of the land use and human activities of the inhabitants of these communities [4] .…”

“…Certain dreadful diseases which cause serious health problems to humans are transmitted by mosquitoes [7] . Since female mosquitoes must have a blood meal as a requirement for oviposition, this gives them a great opportunity to bite man and transmit diseases such as malaria, arborviruses such as zika, yellow fever, dengue, chikungunya, filariasis among others [4,8] . The affected persons suffer immensely and development is hindered [9] .…”

Breeding Preference and Bionomics of Anopheles spp. at the Malarial Endemic Area, Runut Village, East Nusa Tenggara Province, Indonesia

“…[26][27][28][29] Environmental changes such as deforestation could increase local temperatures in the highlands that could enhance the vectorial capacity of the Anopheles. [30][31][32] In Sikka district East Nusa Tenggara, a possibility of occasional changes of potential vectors, seasonal vector changes were reported by Majawati et.al that Anopheles barbirostris was a dominant malaria vector during dry season whereas An. aconitus predominated during rainy seasons.…”

Prevalence of &lt;i&gt;Plasmodium falciparum&lt;/i&gt; Infection Among Pregnant Women Visiting Community Hospitals in Aguata L.G.A., Anambra State, Nigeria

“…Even though the research was carried out in the dry season (October to March), the pregnant women could have acquired the infection during the period of rain when Anopheles mosquito breeding habitats abound and their population tends to increase. This is evident in the statement [16,17], that malaria transmission is affected by season as malaria vector population abounds in the rainy season than in the dry season, and vice versa. In addition, the pregnant women in the study area may not have been sleeping under Long Lasting Insecticide -treated Nets (LLINs) which are meant to offer protection against mosquito bites, thereby preventing malaria parasite infection [18].…”