GLOSSINA INVESTIGATIONS IN NYASALAND. 259 



to secure a newly emerged insect with one's fingers. This doubtless favours the 

 escape of such insects, and of the pregnant females, which take to flight unwillingly 

 and fly heavily. 



No evidence has been seen that any scratching animals habitually seek food in 

 such places, the various Grallatores— francolin, partridge, and guineafowl — which 

 abound in the tsetse areas, preferring more open places, especially where game is in 

 the habit of resting. 



Early in June I returned to the proclaimed area for the purpose of ascertaining 

 whether pupae had been deposited under trees already felled in the district. 



With a view to minimising the numbers of mmsitans along the road running 

 west from Domira Bay, the Government cleared in the middle of last year an area 

 averaging a hundred yards in width on either side for a distance of about eight 

 or nine miles. I may remark incidentally that in January the Resident, who was 

 responsible for the clearing, gave it as his view that the measure had been productive 

 of some benefit. The Medical Officer however, who knows the district well, expressed 

 a very contrary opinion, and I myself found the flies abundant in places and 

 extremely troublesome, though the country was a blackened wilderness as a result 

 of grass fires. Later on, in March, the tall grass and the new shoots put out by the 

 tree- stumps formed abundant shelter for the fly. 



By the clearing process all trees, whether large or small, were cut off at a height 

 of about two feet from the ground, and many, which had fallen before the trunk 

 had been completely severed, rested at one end on the stump, a condition which 

 seems to form beneath an ideal kind of breeding place for the fly. Hundreds of such 

 places now exist there, and as there seemed to be a strong probability that the fly 

 might use some of them as breeding places, I have examined a large number and 

 have ascertained this is actually the case. Pupae in small numbers were obtained 

 under a large number of trees — on 8th July for instance, an unusually good day, 

 30 living pupae and 162 pupa-cases were found — and doubtless as time goes on 

 and the earth under the trees becomes looser, more and more will be obtainable, 

 for the grass fires of this year have done little towards consuming these trees, 

 though they were felled as long as a year ago. My observations there confirm my 

 previous experience, that no special tree is favoured by the fly, which conclusion 

 is further supported by the discovery of a few pupae in wood ash beneath trees which 

 have been partly burnt by grass fires. There is thus no question as to the feasibility 

 of constructing artificial breeding places. 



A further fact of importance is that many of the pupae are to be found in a part 

 of the area from which, concomitant with the drought, the fly has temporarily 

 receded, a point which any scheme for dealing with the fly will require to take into 

 consideration ; and there is also the possibility that pupae so situated may remain 

 quiescent in the soil during the greater part of the dry season, the flies emerging 

 and repopulating the area when a change of season takes place. 



A large number of tsetse pupae found at Monkey Bay in late April, ten weeks 

 ago, are still alive, so far as I have been able to ascertain by opening one or two, 



