MODE OF FEEDING. 21 



wings, buzzing in a minor key, rather like a bee when held 

 forcibly, though not so powerfully : when the keenness of his 

 appetite has been somewhat appeased, he stops working his 

 wings and sucks in silence. If left to himself, he will suck until 

 his originally skinny barred abdomen becomes a large crimson 

 bead [compare Figs. 5 and 6]. He is then almost helpless : if 

 touched he will not fly, and if brushed off he will only go a yard 

 or two, to settle heavily on a bush, or gradually sink down to 

 the ground." A similar account is given by i'oa [135], who 

 writes : — " When it settles, it does so so gently that one does 

 not feel it ; it remains thus motionless for fifteen or twenty 

 seconds, its proboscis projecting in front, in a mistrustful 

 attitude, ready to take flight. When it believes itself safe, it 

 lowers its weapon, separates its feet so as to flatten itself out 

 more and pierces the flesh without causing any pain to start 

 with, as does the mosquito. . . . While its proboscis, which is 

 at least a quarter of a centimetre in length, disappears comr 

 pletely in the flesh, it remains motionless sucking blood, its 

 abdomen swelling and becoming rose-coloured owing to its 

 transpai'ency, and immediately afterwards appearing deep red 

 and plump. It is not until the moment when it has already 

 imbibed a large portion of its meal, that a slight pain or rather 

 itching betokens its presence. When its stomach is full it is 

 still very difficult to catch with the hand, for it does not fly off, 

 but quickly dodges to one side." 



It should be noted that M. Foa's statement that the proboscis 

 of the Tsetse " pierces the flesh without causing any pain to start 

 with," is not altogether borne out by the experience of others. 

 Thus, according to ^Selous [76], the bite of the Tsetse is " far 

 more severe " than that of a flea, and " about one in every ten 

 bites (that perhaps touches a nerve) closely resembles the sting 

 of a wasp or bee, as it will cause one when seated to spring up as 

 if pricked with a needle;" while Colonel Bruce writes* : — "In 

 man the burying of the proboscis in the skin is accompanied by 

 a sharp prick, which draws one's attention suddenly to the spot ; 

 but the pain is, as a rule, trivial, and the subsequent redness and 

 irritation very slight indeed— in fact, less than that caused by 

 the mosquito." Captain Gibbons [152] states that the tread of 

 the Tsetse " is so light that the sharp prick of the proboscis is 

 generally the first indication of his whereabouts." f According 

 to Mr. F. J. Jackson [II9] : — " Its bite in man, though very 



* Cf. Chapter VII., Appendix A, p. 272. t See also [27]. 



