Entomological study on species composition, behavior, longevity and probability of surviving sporogony of Anopheles mosquitoes in Lare District, Ethiopia

Abstract

In order to develop efficient malaria vector control strategies, this study was conducted to assess species composition, relative abundance and longevity of Anopheles mosquito malaria vectors in Lare district, south western Ethiopia. For this, Anopheles mosquitoes were collected using CDC light traps catch and pyrethrum spray collection for five months from May to September, 2016. Four kebeles (the smallest administrative unit in Ethiopia, three houses per each kebele) for CDC light trap catches collection and 20 households from each sampled kebeles for pyrethrum spray collection were selected randomly. A total of 2735 Anopheles mosquitoes belonging to four species were collected during the study period. Anopheles gambiae s.l. 1914 (69.9%) was the predominant malaria vector followed by Anopheles pharoensis 602(22%), Anopheles nilli 137(5%) and Anopheles coustani s.l. 82 (3.10%). Significant (p<0.05) variations existed in mean density of mosquitoes per month, but not in mean mosquito density per site (between sampled kebele). The highest mean longevity of A. gambiae s.l. was 9.4 days in July, while probability of surviving sporogony was 0.52 and 0.56 for P. falciparum and P. vivax, respectively. Thus, this study could contribute to the basic understanding of age, distribution and behaviour of anopheles mosquitoes in Lare district for evidence based malaria vector control program. Key word: Anopheline species, longevity, sporogony, plasmodium, Ethiopia.