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OBSERVATIONS ON THE OCCURRENCE OF GLOSSINA IN 

 THE MONGALLA PROVINCE OF THE ANGLO-EGYPTIAN 

 SUDAN. 



By Harold H. King. 



Government Entomologist, Anglo- Egyptian Sudan, Wellcome Research 

 Laboratories, Khartoum. 



(Map.) 



The following is a report on the distribution of the tsetse-flies, Glossina 

 palpalis, R. D., and G. morsitans, Westw., in the Lado District, through which I 

 travelled during the first six months of 1911, together with some brief notes on 

 their bionomics. My route and the localities in which the tsetse-flies w^ere seen 

 are shown approximately on the attached map, and owing to the impossibility of 

 showing them accurately — most of the khors and villages over and through which 

 I passed are not marked on the map — a route report is also appended. From 

 December 30th, when I left Shambe, till March 8th, when I reached Meredi, I 

 travelled in company with El Bimb. C. M. Drew, M.C., and from May 2nd, 

 when I arrived at Kajo Kaji till July 2nd, when I reached Rejaf, I was with 

 El Bimb. C. H. Stigand, Inspector of the Rejaf and southern portion of the 

 Lado District, to whom I am indebted for much valuable assistance. 



The only two species of tsetse-fly noted were the two mentioned above, viz., 

 G. palpalis and G. morsitans. 



Notes on the bionomics of G. palpalis. 



This species appears to be equally bloodthirsty at all hours of the day — from 

 dawn till dusk. On dull cloudy days it is not so active, and on such days on 

 khors where it is not very plentiful one may experience considerable difficulty in 

 finding a single specimen. I have noticed, too, that on sunny days when one is 

 being pestered by from 12 to 20 flies, a cloud obscuring the sun will cause the 

 number to decrease to from four to six. 



One cannot definitely state that a khor is " fly-free " after having spent 

 merely an hour or two in looking for G. palpalis. As an instance of this — I 

 arrived at a khor at 10 a.m. on a cool cloudy day and camped on its bank. I 

 spent a considerable time that day in collecting in the bed of the khor but saw 

 no G. palpalis, and it was not until the afternoon of the next day that a single 

 specimen appeared in camp. Doubtless, too, on khors which do not contain water 

 except during certain seasons of the year, one might search in vain for " fly " 

 during the dry seasons. For these reasons I am of the opinion that if one crosses 

 a number of khors during the day's march and finds G. palpalis on some of them, 

 one may safely conclude that " fly " also exists on the others, provided that they 

 are of a similar nature to those on which " fly " was actually found. 



It is difficult to say what is the greatest distance from its haunts for which 

 this species will follow a man or animal. A mile is certainly within its limit, for 

 on several occasions I have had a specimen follow me for this distance and have 

 then caught it. 



