92 BIONOMICS OF GLOSSINA BEEVIPALPIS. 



Glossina hrevipalpis, which is often met with in veiy large 

 numbers, is found, at altitudes varying from sea-level to some 

 1,700 feet, as a rule only where there is abundant shade and 

 protection from wind, its favourite haunts consisting of bush 

 mixed with creepers and young forest trees, either close to 

 watercourses (dry or otherwise), or at any rate within a few 

 hundred yards of water. Stuhlmann has encountered the fly 

 close to the sea, near Dar es Salam, and Davey records the 

 occurrence of a single specimen amongst "bango" reeds a few 

 yards from the edge of Lake Nyasa. Sanderson has been 

 informed by natives that during the rains {i.e. about January), 

 " at which time practically the whole country is under water," 

 the species is very prevalent in North Nyasa all over the grassy 

 plain lying between the shore of the lake and a line of foot-hills 

 some ten miles away, but this statement requires confirmation. 

 Like G. palpalis and other species of Tsetse, G. brevipaljns will 

 occasionally follow cattle and other animals to some distance 

 from its usual haunts ; Stuhlmann states that . in this way, 

 especially during the hot weather, isolated specimens were 

 frequently found for a time among the mountains of East 

 Usambara, at an altitude of from 800 to 1,000 metres (2,600 to 

 3,250 feet), while, during the period from December to April, 

 others have often been met with in settlements such as 

 Kwamkoro and Amani. Davey records the capture of a single 

 individual " on the finger of a native standing under a tree in 

 the middle of a small village," and in another village Sanderson 

 once caught two specimens in a hut occupied by natives, and 

 also containing a cow infected with trypanosomiasis. 



The present species of Tsetse is active and desirous of feeding 

 only at two periods of the day — early in the morning before 

 8.0 o'clock, and in the evening, from about 4.0 p.m. onM'ards. 

 The intervening hours, from 8.0 a.m. to 4.0 p.m., are passed by 

 G. hrevipalpis in concealment, " under leaves of bushes or in the 

 grass, always near the ground ' (Sanderson), or low down on the 

 trunks of trees, two or three feet from the base. While thus 

 resting motionless the flies are difficult to discover and capture, 

 and " their pi-esence would be entirely unsuspected " (Sanderson) ; 

 at Kaporo, near the north end of Lake Nyasa, Davey found that 

 they preferred to rest on " trees surrounded by creepers and 

 undergrowth, and hid away in crevices in the bark or under the 

 oi'igin of branches." Both Dave}^ and Sanderson observed a pair 

 in coitu on a tree-trunk, in the one case at midday, in the other 



