FfiEblNG-TlME OF TSETSE. it 



it with the hand at common temperatures ; * in the cool of ihe 

 mornings and evenings it is less agile." Again, accoi"ding tiii 

 Colonel Bruce,]" — " The Tsetse is not at all easy to catch with the 

 hand, especially during the day, being nimble and quick of move- 

 ment, but at early morning or sunset they become more lethargibj 

 and are then more readily secured." The following' remarks by 

 Sir John Kirk [28] are also worth quoting : — " In the mornings 

 ■while the dew hangs on the grass, and before the heat of the 

 rising sun has warmed the air, the Tsetse is dull and sluggish, 

 resting on the under side of some leaf or blade of grass ; wheii 

 forced to take wing they may then be easily caught. Even at nine 

 o'clock they are not very active, and fly about with a peculiar 

 buzzing sound ; with the heat of the day they become a real 

 annoyance to the traveller, constantly biting him on the hands, 

 face, or neck, dexterously evading a blow, and again alighting on 

 the very spot from which they have been driven." 



According to Captain Crawshay,| the Tsetse bites "at any 

 time," but is " most aggressive " " during the hottest hours of the 

 day " ; Bradshaw [77] says, " It bites throughout the day, except 

 when it rains " ; and Selous [76], writing of the plague of Tsetse- 

 flies on the south bank of the Zambesi and Chobe, to the west of 

 the Victoria Falls, in 1874, speaks of the insects as' " attacking 

 one in a perfect swarm, from daylight till sunset." On the other 

 hand. Colonel Bruce, describing his experience of Tsetse-flies in / 

 Zululand, says : " About sunset seems a favourite feeding-time, / 

 and ■ then the poor creatures [horses] would be surrounded by a / 

 perfect cloud of the flies, while some hundreds "of them would be 1 

 settled on them at the same moment. "§ Again, it may 'be noted 

 that Dr. W. S. Radford, referring to a species of " gM-fly " (i.e.', 

 horse-Jiy) in Jubaland, East Africa Protectorate, the bites of 

 which he asserts produce in camels symptoms " identical in every 

 particular with those produced by Tsetse," states that " This 

 fly, unlike the Tsetse, attacks animals during the day at all 

 hours.'ll The inference from this, although Dr. Radford does not 

 mention the period of the day at which Tsetserflies in Jubaland 

 are most aggressive, is opposed to the testimony of Crawshay, 

 Bradshaw, and Selous, which has already been quoted. But the 

 explanation may very possibly be that the Jubaland Tsetse-fly 



* Baines [55] states that on a cold day the fly is "dormant." — E. E. A. 



t Cf. Chapter VII., Appendix A, p. 272. 



; Chapter VII., Appendix B, p. 288. 



§ Cf. Chapter VII., Appendix A, p. 272. 



11 Chapter VII., Appendix C, p. 293. / ' ' " 



C 



