Occurrence and monthly dynamics of phlebotomine sand flies in parts of Sokoto State, north-west Nigeria

Abstract

Phlebotomine sand flies are small tropical insects that have been implicated as vectors of several disease agents, including those responsible for the various forms of leishmaniasis. A study to determine the occurrence and monthly dynamics of phlebotomine sand flies (Diptera: Phlebotominae) was conducted in three Local Government Areas (Wamakko, Sokoto South and Kware) of Sokoto State, Nigeria between May-November, 2016. A total of 1260 flies were collected using modified sticky traps placed in the various biotope types (refuse dumps and sewage tanks). Two sand fly  genera Phlebotomus and Sergentomyia were encountered. It was also observed that males account for 860(68.3%) while the total number of female  specimens was 400(31.7%). More flies were captured in Wamakko LGA of the State with a total number of 757 samples (60.1%), followed by Sokoto South LGA with a total number of 503(39.9%). Refuse dumps harboured 1,149 flies (91.2%) more than sewage tanks with a total number of 111(8.8%). No flies were captured in Kware LGA. Sand flies were more abundant in the peak rainy season of August and September and less or absent in the dry months. It was observed that rainfall and relative humidity were essential meteorological factors that determined the occurrence of sand flies in the study area. This study confirmed the occurrence of phlebotomine sand flies and the possibility of Leishmania transmission in the study-area.

Keywords: Occurrence; sand flies; Phlebotomus; Sergentomyia; Leishmania; Sokoto.