64 



Thus, it was only after the Mission had been established in the 

 Bukama-Sankisia region (Katanga) for seventeen months, during 

 which a very large number of Tsetse-flies had been collected, that Dr. 

 Rodhain was fortunate enough to capture a solitary specimen (a male) 

 of G. brevipalpis, enabling him to establish the existence of the species 

 in the centre of Katanga. As regards the distribution of this species 

 in North Katanga, much information will be found in Schwetz's papers 

 (132). 



The habits of G. brevipalpis, as observed by Dr. Bequaert at Kibombo, 

 were very different from those of G. palpalis. The insects were met 

 with in the forest, a long distance from any water, and usually made 

 their appearance about 5 or 6 o'clock in the evening, when they were 

 to be seen on leaves or on sandy paths. In these places they were 

 never met with in the morning, or about 2 or 3 o'clock in the afternoon. 

 It likewise appeared to Dr ( . Bequaert that this species is little inclined i 

 to attack man (vide also Swynnerton's statements (145) with reference 

 to G. brevipalpis in Portuguese East Africa, p. 76), which perhaps to 

 some extent explains the difficulty found in proving its existence in a 

 district. 



With reference to the other species of Tsetse, namely, G. pallicera, 

 Big., G. longipalpis, Wied., G. fuscipleuris, Austen, G. nigrofusca, 

 Newst., G. tabanijormis, Westw., G. severini, Newst., and G. schwetzi, 

 Newst., reported as existing in one or other part of Belgian Congo, 

 we possess no records of occurrence other than those already given in : 

 Chapter II., p. 11 ci seq. 



CHAPTER VII. 

 POINTS IN BIONOMICS. 



Seasonal Migrations Range of Flight Travelling Habits Resting 

 Surfaces Proportion of the Sexes. 



We have included the subjects mentioned above in the same chapter, 

 since the majority of them are more or less intimately related, while 

 in some cases they are still far from being elucidated. 



The seeker after knowledge concerning Glossina will find himself 

 -confronted with a number of questions such as the following : Upon 

 what do the seasonal variations in the numbers of Tsetse-flies depend, 

 .and what are the exact relations between these variations and the 

 meteorological conditions ? Is the diminution in numbers in the course 

 of the dry season due to the scarcity of the animals whose blood 

 serves fo/food, to destruction by birds or other enemies, to lessened 

 production of larvae, or to the prolongation of the duration of the 

 pupal period ? In the event of a prolonged drought, is it possible 

 that all the adult flies perish, and that the perpetuation of the species 

 is ensured only by the hatching of old pupae at the commencement of 

 the rainy season ? 



What is the reason why Tsetse-flies are sometimes met with on one 

 of the banks of a river, and not on the other ? Is this due to the soil 

 in the one case being more favourable for the deposition of larvae, or to 

 other causes ? 



On the other hand, why do male flies usually appear to be in the 

 majority ? Does their number vary with the locality, as in the case 

 of G. palpalis, and does it depend upon the situation of the breeding > 



