Abstract

The present study was carried out to spot the limit of tsetse fly belt in the Blue Nile State as the consecutive ecological changes tend to create significant modification in tsetse distribution. The survey was carried out for three weeks during March, 2011. Traps were placed in various vegetation types assumed to possibly harbor tsetse flies and were placed 200 m for three days at each site and harvested after 24 h. The sites where tsetse flies were encountered were marked using Global Positioning System (GPS) and the maps were generated. Tsetse geo-distribution generated map revealed that Glossina fuscipes fuscipes and Glossina morsitans submorsitans co-existed in Yabus District. Nevertheless our findings of G. m. submorsitans in the area far north is not surprising given that tsetse populations are known to recover from refugia following intervention or re-colonisation of a cleared zone from neighboring sources. However, G. f. fuscipes using biconical traps were only encountered in the river Khor Yabus extending to the East up to Platoma more than 35 linear Km west from the Ethiopian border. The apparent densities vary from 0.3 to 8 flies/trap/day, and tremendously decreased from east to west. The G. m. submorsitans flies using transect fly-round technique were caught north of its previously known limits which amounted to roughly 45 linear km north of River Khor Yabus to areas which had been assumed as devoid of the species

Key words: Spatial-distribution, Glossina fuscipes fuscipes, G. morsitans submorsitans, Blue Nile State, Sudan.