402 MEDICAL ENTOMOLOGY 



African boys employed in field laboratories excel in this work and make 

 quite a lucrative living out of it. The puparia on being brought to the 

 laboratory should be placed in glass jars, similar to those used in 

 breeding the Muscidae (see page 343 and Plate XLIV, fig. 5) ; or in small 

 boxes, such as the one devised by Bruce. 



Kleine, who has given a complete account. of his methods of breeding 

 Glossina palpalis, always used large specimen jars, 8*5 cm. in height 

 and 6*5 cm. in width. All observers who have used tsetse flies for trans- 

 mission experiments have abandoned the earlier methods of keeping the 

 flies in large airy wooden cages with moist grass, rocks and other natural 

 objects ; the flies do not thrive in them, and are very difficult to control. 

 Ants and other laboratory pests soon make their way into the cages and 

 destroy the flies. 



In keeping palpalis in his fly jars, Kleine takes the precaution of 

 covering the top with a fairly wide-meshed mosquito net, the meshes 

 being just narrow enough to prevent the deposited larvae from crawling 

 out. He points out that the jars must be kept scrupulously clean, and 

 that the flies must be regularly fed ; the feeding, though carried out by 

 the African boys, must be under the control of one of the members of the 

 laboratory. The flies are fed daily, often twice a day, on sheep and 

 goats. The animal is first tied down, the side of the abdomen then shaved 

 over a large area, and the jar is inverted over it without exerting any 

 pressure ; it is kept like this until all the flies have fed. This may occupy 

 a considerable time, as some flies are very slow in finding a suitable spot. 



As a rule Kleine kept three flies in each jar, two females and one male, 

 but never more than five ; if too many are placed together they are apt 

 to become damaged by a deposit of faeces on their wings and bodies. 

 Kleine lined the bottom of the jars with several layers of filter paper, 

 which soaked up most of the liquid faeces. The flies should never be 

 fed on unhealthy or anaemic animals, or on cold-blooded animals.* 

 The feeding experiment should not be begun till the temperature is warm. 

 The flies will suck blood on the first day after hatching, but do not feed 

 actively till after the second. The jars should be changed daily and if 

 possible twice a day, and great care should be taken that the fresh jar is 

 absolutely dry. The changing of the flies from one jar to another is 

 accomplished in the following way : The clean jar is placed on a table 

 and the one containing the flies inverted over it, so that the mouths of 

 the two are in perfect contact ; the mosquito netting is then untied and 



* Lloyd notes that when morsitans was fed on fowls, the blood forms a hard clot 

 in the crop. 



