103 



Newstead (R.). First Preliminary Report on the Bionomics of 



Glossina morsitans. — Repts. Sleeping Sickness Comm. R. Soc., 

 London, xv, 1914, pp. 142-157, 3 plates. 



This is a report of the expedition made by the author and Dr. J. B. 

 Davey in Nyasaland in 1911, for the purpose of investigating certain 

 facts in connexion with the bionomics of Glossina morsitans, and of 

 devising, if possible, some means for its control, so that the authorities 

 might be in a better position to check the spread of sleeping sickness 

 in the Protectorate. 



The country between Liwonde and Lake Malombe was traversed, 

 as in that part the fly-area had been found to be more or less continuous ; 

 both banks of the river Shire were studied and the camp finally pitched 

 near its banks about four miles south of Lake Malombe ; this camp 

 was occupied from July 18th to Nov. 2nd. A description of the 

 physical features, climate, vegetation and vertebrate fauna of the 

 district is given. Regarding the big game, it is stated that impala 

 antelopes {Aepyceros melampus) are so abundant and so constantly 

 present in this district that they probably supply a large proportion 

 of the blood necessary for the life and propagation of the tsetse. Large 

 troops of baboons [Papio habuin) were also seen. The flies apparently 

 did not attack birds. 



The fly seems to be confined to the low forest country and does not 

 usually leave it, unless to accompany man or animals whose blood it 

 can suck. Flies were liberated in more open spaces, where conditions 

 were on the whole favourable to their existence ; these flies were 

 marked and it was hoped to ascertain whether they would remain, 

 or fly back to their original habitat. The number of flies experi- 

 mented with was too few to give satisfactory results ; one fly, how- 

 ever, appears to have traversed the more open country for a mile and 

 to have returned to the place where it was originally captured. 



Counts were made to ascertain the proportions of the sexes at 

 different times. In dry weather the proportion of males was consider- 

 ably greater than that of females ; in wet weather their predominance 

 was less marked. 



Pupae of G. morsitans were found in four different parts of the 

 forest, all occurring in the so-called " sanya " country. The first 

 pupa was found at the foot of a sanya or mopani tree (Copaifera 

 mopane), about three-quarters of an inch below the surface of the 

 soil. The second was lying at the foot of a tree buried about four 

 inches deep in the earth of a termites' nest. These two pupae were 

 empty. The third, which was living, was found just below the surface 

 in a small quantity of earth in a cavity at the base of an ebony tree. 

 The fourth, which was also living, was found in loose earth among 

 the projecting roots of a baobab tree. 



Breeding experiments showed that apparently the breeding season 

 is continuous throughout the year ; but it is likely that it is more 

 extensive at the commencement of the rains and also at the end of 

 the wet season than during the dry months. In two cases, the pupal 

 period lasted for 26 days, and in one 24 days. The flies experimented 

 with were fed on the blood of native fowls ; the number of meals taken 

 by the different females varied to a marked degree ; the average 

 duration of time between each meal was 2 "56 days. 



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