34 



As regards species of Glossina other than the foregoing, Austen, 

 writing of G. brevipalpis, remarks : " At Amani, the duration of 

 the pupal stage was found by Stuhlmann to be from 30 to 65 

 days, according to the temperature ; when pupae were kept in the 

 breeding-cage at^30C. (86 F.) the flies emerged on the average in 

 about 36 days." In Stuhlmann's opinion the pupal stage lasts 

 somewhat longer in G. brevipalpis than in G. austeni. On the other 

 hand, Dr. Roubaud (119) in Dahomey, studying G. longipalpis in 

 captivity, found that the duration of the pupal stage in this Tsetse-fly,. 

 at a mean temperature of 24-25 C. (75-2-77 F.) varied from 

 26 to 35 days. 



CHAPTER IV. 

 BREEDING PLACES BREEDING SEASON. 



BREEDING PLACES. Existing knowledge on the subject of the 

 breeding places of Tsetse-flies relates chiefly to the two best-known 

 species : Glossina palpalis, the disseminator of sleeping sickness in 

 West and Central Africa, and G. morsitans, the carrier of the Rhodesian 

 form of sleeping sickness and of nagana of domestic animals. 



G. palpalis. The larva of this species is deposited by the female in a 

 shady place, usually, though not invariably, near water, * where the soil is 

 light and sandy, moderately dry, and often composed of vegetable debris. 



According to Simpson (144), in the Gold Coast the breeding places 

 of G. palpalis are very similar to those of G. tachinoides, the most 

 common situation in both cases being in the decaying humus beneath 

 overhanging trees, where the sun seldom or never penetrates, and the 

 ground is never really dry. 



In Uganda and the Katanga district of Belgian Congo, pupae of 

 G. palpalis have been found in large numbers in sandy spots ; and 

 Dr. H. L. Duke (47), from investigations made by himself and others 

 on islands in Lake Victoria, concludes that the chief characteristics of 

 the favourite breeding sites of this species are shade and free air 

 circulation, accompanied by dry and loose soil, generally gravel or coarse 

 sand. Fiske (54), however, while stating that the latter are frequently 

 chosen, has shown that fine, dry vegetable debris serves as well. 



In the Congo pupae of this species have also been met with on trees 

 (in the forks of branches beneath accumulations of earth or moss, in 

 clefts in the bark and elsewhere), up to a height of three and a half 

 metres from the ground. 



After a number of unsuccessful attempts, Dr. Bequaert (116), a 

 member of the Mission Scientifique du Katanga, succeeded in dis- 

 covering in 1911 two breeding places of G. palpalis near Bukama, on 

 the Lualaba. The first of these, at the Kalengwe rapids on the river 

 just referred to, 12J miles north-west of Sankisia, yielded at the initial 

 examination on 4th August 1911, 21 empty Glossina pupa-cases and 

 three living pupae ; the latter produced two G. palpalis and one ^ 

 G. morsitans. The pupae were found shallowly buried in light sand (a 

 sand-bank submerged during floods, but high and dry in the dry season) 

 collected between large roots at the base of a tree trunk, and very dry 



J In Uganda, Fiske (54) found a breeding place of G. palpalis at a distance of 



yards from the margin of Lake Victoria; and quite recently Dr. Schwetz 



(136 a) has recorded his discovery of a living pupa and four emptv puparia of 



this species in a thicket 1,500 metres (1,640 yards) from water in 'the Rwanda 



district of Belgian Congo. 



