NOTES ON TSETSE-FLIES OF NYASALAND. 103 



On two successive nights camp was pitched in locaUties where these pupae were 

 being obtained with a view to ascertaining whether brevipalpis is nocturnal as well 

 as crepuscular in its habits. Though 32, all males, were taken at dusk, between 

 6 and 6.15 p.m., all within 50 yards of the tent, two only were taken inside it. 

 None were taken after dusk, though the nights were bright and starlit, nor were they 

 attracted to the camp lamps. At about 8 p.m. a search was made in the bush by 

 the hght of a bullseye lantern, but again the flies were neither seen nor heard ; and 

 though the party of 23 natives slept out in the open, few having blankets, none 

 complained of having been troubled by the fly. 



The breeding grounds of this fly were further studied in October, some two 

 hundred miles north in the vicinity of the Lufixa River, North Nyasa, close to the 

 Lake, a locahty long notorious for the fly, the places selected by it having the same 

 character as all the breeding places previously examined. In this neighbourhood 

 13 new puparia and 9,094 old ones were collected between the 7th and 18th of the 

 month, only 14 of which showed perforations suggesting the exit of parasites. 



In the course of the journey through the fly-infested villages north of Kotakota 

 the method was witnessed by which the natives of that part, while sitting down, 

 catch, with the least effort to themselves, flies settled within reach on their bodies. 

 The blade of an old sheath-knife or an old spear blade is placed almost flat on the 

 skin and is then advanced, with the edge shghtly raised, by no means slowly or even 

 very carefully, towards the fly, which, though very alert in regard to menace from 

 above, evinces no apprehension of that below it. When the edge is well over its 

 feet the native presses them on to his skin with it, and the fly, so trapped, is then 

 taken in the fingers and subjected to treatment such as is doubtless considered 

 justifiable by reason of the annoyance it has caused. 



Suggestions in regard to Tsetse Control. 



One of the most pressing entomological problems at the present day in the British 

 Empire is that of the control of the various species of tsetse-flies. As shown by a 

 number of workers, the parasites destructive to their puparia are not few, at all 

 events in the case of G. morsitans, and in some areas these parasites are known to 

 exert a considerable influence in reducing the numbers of the fly. But, generaUy 

 speaking, no very material reduction, from the point of view of man, would seem 

 to be effected by these agencies ; though at this early stage of research in regard 

 to the fly it may perhaps be premature to make any unquahfied statement as to their 

 control value. Instances have been recorded where the tsetse-fly in a district has 

 unaccountably diminished without there being any marked diminution in the numbers 

 of the game animals therein. Major E. E. Austen in his " Handbook of the Tsetse- 

 flies " (1911, p. 65) mentions the disappearance of G. morsitans from the Victoria 

 Falls, where at one time it abounded. The late Captain F. C. Selous, in his book 

 " African Nature Notes," speaks of the disappearance of the flies at the same time 

 with buffalos from the valley of the central Limpopo and its tributaries, where 

 other game — ^kudu, zebra, wildebeeste, hartebeeste, impala and bushbuck — 

 continued to exist in considerable numbers, and he suggests that the flies died out 

 because they were unable to maintain themselves on game other than buffaloes. 

 More recent study of the flies has shown that this is not the case, and the writer 



