290 INSECTS AND MAN 



of seven segments ; at the hinder margin of each segment 

 is a set of three pads, each covered with minute spines, 

 directed backwards; these assist in locomotion. On the 

 last segment are three spiracles or breathing pores ; whilst 

 on the first segment are two black mandibles surrounded 

 by paired groups of small spicular teeth, forming a sort of 

 cupping instrument. Under normal conditions they pass 

 through two moults and become fully grown in about a 

 fortnight. 



The larvae are exclusively blood feeders, and in this 

 connection one or two interesting points may be noticed. 

 As is so often the case with insects which rely on an active 

 host for their food, they are able to endure long fasting 

 periods. A more curious trait is that when below ground 

 and hungry they show a remarkable sensibility to heat, 

 the slightest rise in temperature causes them to become 

 active and to travel towards the source of heat; when 

 fully fed slight changes in temperature do not appear to 

 affect them. The reason for this phenomenon is obvious 

 a hungry Congo floor maggot is anxiously waiting beneath 

 the soil for a meal; should he venture above ground he 

 would probably be injured, accidentally or purposely, so, like 

 many more noted individuals, he waits, and mayhap some 

 native, seeking rest and sleep, will throw himself on the 

 ground; soon the warmth from the human body will 

 penetrate to the waiting maggot, this is the signal that a 

 meal is at hand; aided by his spinous foot -pads, he 

 wriggles through the soil and takes his fill, before again 

 retiring to his subterranean home. The pupa, as is so 

 frequently the case with Diptera, is dark brown and tub- 

 shaped. We have mentioned that this species is African ; 

 it ranges from Natal to Nigeria, and its distribution is 

 aided by the fact that it is often carried from one village 

 to another, in the egg or larval stage, in the dirty mats 

 which the natives are in the habit of transporting from 

 place to place. 



