TACHINOIDES IN BOKNU PROVINCE, NORTHERN NIGERIA. 



125 



Coutiuuing through the long grass along the river-hank, in most places no flies 

 were to he seen, hut at particular spots a few would appear, though it was 

 impossible to find out where they came from. Returning to the village about 

 5 p.m., a few flies followed us, and were very persistent in their attempts to 

 obtain a feed of blood. At another part of the river, about half an hour later, 

 we found the flies numerous at a spot where the natives generally draw their 

 water. They appeared to come out of a particular thicket, but of this I am not 

 at all certain. They continued to bite in gradually diminishing numbers till dark, 

 when they entirely disappeared. 



The next day we proceeded up-stream for six or seven miles, and again found 

 that G. tachinoides occurred intermittently in restricted patches along the route ; 

 but we did not observe any beyond Gellen. Numerous villages occur along the 

 banks, and to the inhabitants the flies are well known, under the name of 

 " tatchiga." They said that these insects were a perfect nuisance in the middle 

 of the day, giving the people no peace at all. 



On first going down to the river at Gellen, we sat down for a few minutes on the 

 rocks shown in the photograph (fig. 5), and no flies appeared, but after about ten 

 minutes, one or two were seen about us, and they gradually increased in numbers 

 till they became quite numerous. On sending a few men to the opposite side of 

 the river, it was found that the tsetses were much more numerous there, and 

 seemed to come out of the bushes shown immediately behind the two standing 

 figures (fig. 6). 



-Hawal River, at Gellen, near Wajerou ; G. tachinoides appeared to be 

 harbouring in the bushes above the heads of the natives. 



