Spatio-Temporal Variations and Apparent Density of Tsetse Flies (Glossina Species) in Selected Old Focal Areas of Niger State, Nigeria

Abstract

Spatio-Temporal variations and apparent density of tsetse flies (Glossina Species) in selected old focal Areas of Niger State was studied. Niger state is an old endemic focus of African trypanosomiasis and the vector tsetse fly (Genus: Glossina). Despite the economic and public health impact of the disease in Nigeria, there is no prevailing tsetse record in the various ecological areas of Niger State. Three (3) sites were selected; Bida (Bida LGA), Gbangban (Edati LGA) and Ijah Gwari (Tafa LGA) being old foci of tsetse and trypanosomiasis. Temperature, relative humidity and geo-reference of each sampling point were taken using thermometer, whirling hygrometer and GPS machine while Biconical and Vouvoa tsetse traps were used in catching tsetse flies for 3 days (72 hrs) in each selected site. Catches were removed daily (24 hrs) and identified using standard morphological features and relative abundance recorded. The results were considered significant at p<0.05. The mean temperature range was 28.48±0.27oC - 32.04 ± 0.42oC, while relative humidity was 66.86 ± 1.22% 74.84 ± 2.19%. The altitude in Ijah Gwari was 494 ± 23.5 m (above sea level), Bida was 109 ± 6.80 m and Gbangban was 93.17 ± 5.18 m. More so, the latitude recorded for Bida was 9.12 ± 0.01oN, Gbangban was 9.14 ± 0.00oN and Ijah Gwari 9.18 ± 0.01oN. A total of 2,251 tsetse flies were caught during the study period. Bida recoded 227 (10.1%), Gbangban 437 (19.4%) and Ijah gwari 1,587 (70.5%). The flies were Glossina palpalis palpalis 2,046 (90.9%) and Glossina tachinoides 205 (9.1%) both species belong to subgenus Nemorhina. A Glossina abundance of 2.09 Tsetse/Trap/Day (T/T/D), 4.04 T/T/D and 14.69 T/T/D was recorded for Bida, Gbangban and Ijah Gwari respectively. The difference is attributable to diverse level of vegetation exploitation in study areas.