Distribution and abundance of anopheles mosquito species in three selected areas of Taraba State, north-eastern Nigeria

Abstract

Most mosquitoes are of public health problem because the females consume blood and transmit diseases. The study was carried out between September 2015 and August 2016 to determine the diversity of Anopheles species in Taraba State, Nigeria. Indoor mosquitoes in Ardo Kola, Bali and Donga were collected using pyrethrum-spray catch. 1073 Anopheles mosquitoes were identified to 20 species level. The identified Anopheles gambiae species complex further analyzed to determine sibling and molecular species using PCR-Restriction Fragment Length Polymorphism assay contained An. coluzzii (former An. gambiae ss M form) 725(95.6 %) An. gambiae (former An. gambiae ss S form) 24(3.2 %), An. coluzzii/An. gambiae hybrid 9(1.2 %) and An. arabiensis 1(0.19 %). Among the Anopheles species, 640(59.6 %) which composed of 14 species were from Ardo Kola, 305(28.4 %) composed of 15 species were from Bali and 128(12.0 %) composed of 7 species were from Donga, all dominated by An. coluzzii which was 66.4, 21.2 and 12.4 % respectively of all An. coluzzii, followed by An. constani in Ardo Kola and An. rivulorum in Bali and Donga. An. gambiae, An. gambiae M/S hybrid and An. arabiensis were only found in Bali 24(100.0 %), 9(100.0 %) and 1(100 %) respectively. An. pariensis was only found in Donga 1(100.0 %). The distribution of Anopheles in months did not appear to follow a particular pattern, although observed to be generally low in dry months. Analysis of variance showed significant difference in abundance of Anopheles species in study areas (p<0.05). This means that the inhabitants of the study areas are, all year round at risk of mosquito borne-diseases.

Keywords: Abundance, Anopheles species, Sympatric speciation, Vector ecology, Guinea-savanna, Nigeria