38 



the Upper Shire Valley, larger numbers of pupae would probably 

 exist in similar habitats." 



More extensive investigations upon the distribution of breeding 

 places of Glossina morsitans were made in Northern Rhodesia ("at 

 Ngoa, in the Mpika division, on the high ground of the Congo-Zambesi 

 watershed ") between January and August 1913, by Mr. LI. Lloyd 

 (89), who summarises his very important results as follows : 



" Searches for the pupae in nature have resulted in the finding of 735 

 living pupae and 1,500 empty cases in 189 positions. A summary of 

 these gives the following results : 



" (a) In 40 instances the pupae were found in hollows in trees, 75 

 pupae and 350 cases being taken. The hollows are at varying heights 

 from the ground up to six feet, and are sometimes filled with very hard 

 clay and sometimes with soft soil, dead leaves, the droppings of insects, 

 and the stomach-castings of birds. When the surface is hard the 

 living pupae are found in crevices or quite exposed on the surface. 



" (6) In 30 instances pupae were found below trees or branches 

 which slope at an angle or run parallel to the ground before rising. 

 In such positions 129 pupae and 197 cases were taken. The ground 

 was usually very hard, and the pupae were taken on or near the 

 surface or in cracks. 



" (c) Beneath fallen dead trees or branches 100 positions yielded 

 493 pupae and 759 cases [see Plate V, Fig. 1] ; these include the most 

 important breeding places. In such places accumulations of dead 

 leaves and twigs usually occur, and the pupae are found among these. 

 When they are absent, the effort to burrow is great, and pupae have 

 been taken at a distance of 18 inches from the shelter of the tree. 

 The trunks were often raised one or two feet above the ground, so there 

 was ample room for any insectivorous animal to search beneath them. 



" (d) Pupae were found in six instances in the chambers of termite 

 nests in rotten upright stumps ; 19 pupae and 61 cases were found in 

 these positions. In several cases the termites were still living in the 

 nests. 



" (e) In ten instances they were found in the burrows of various 

 animals, 14 pupae and 99 cases being taken These are usually the 

 holes of bush-pig or wart-hog, but pupae have also been found in smaller 

 burrows. 



" (/) Pupae were taken three times in the hollows in old termite 

 mounds excavated by the large mammals for the sake of the salt ; 

 five pupae and one case were found in these. 



" The larvae are thus not always dropped in places where they can 

 hide in the earth or under debris, nor are they always placed in positions 

 where scratching animals could not find them. It is a common feature 

 to find the pupae in places where they are daily warmed by the sun 

 for some hours. This shortens the pupation period, which is dependent 

 on temperature. The one feature which is common to all the breeding 

 places found is that above them there is always some relatively dark 

 spot in which the female fly may rest concealed during pregnancy. It 

 is believed that this, rather than any care for the offspring, is what 

 guides the mother fly in the selection of breeding spots." 



Mr. Lloyd states that, in the investigations the results of which are 

 summarised in the foregoing paragraphs, " special attention " was paid 

 "to an area of about two square miles," which was " repeatedly and 

 systematically searched for pupae." In this area 174 breeding places 

 were found, and the plan published with the author's paper indicates 

 their distribution in relation to native and game paths, fords, drinking 



