﻿90 HAROLD H. KING — OBSERVATIONS ON THE OCCURRENCE OF GLOSSINA 



I spent a large amount of time on certain khors and rivers on which G. palpalis 

 was abundant in trying to find its pupae, but did not meet with much success. 

 At Yei I unearthed three empty pupal cases which I believe to belong to this 

 tsetse, but cannot be certain of their identity until they have been compared 

 with determined specimens. They were all found in light loamy soil, about an 

 inch below the surface, under bushes, in dense shade on a fairly steep bank about 

 six feet above the water. 



Natural enemies of G. palpalis. 



The following five creatures were found to prey upon G. palpalis in its adult 

 form : — Two birds, a lizard, a spider, and a mantid. I hope to get these 

 determined shortly. I do not think very great importance attaches to any of 

 these natural enemies, for from the observations made it would appear that 

 G. palpalis is by no means the exclusive diet of any of them. One of the birds — 

 a Bee-eater — is probably more useful than any of the others and yet G. palpalis 

 existed in considerable numbers in the immediate vicinity of a colony of these 

 birds. 



Notes on the bionomics of G-. morsitans. 



I saw comparatively few G. morsitans on this journey and nowhere did it 

 appear in sufficient numbers to constitute a nuisance. As an example of the 

 difficulty of ascertaining whether this tsetse exists in any particular locality 

 unless one has a lot of time to spare, I may mention one instance. On a bright 

 sunny afternoon I was walking along a path and noticed numbers of a species 

 of fly, resembling in the distance G. morsitans, sunning themselves on the path. 

 They always flew away on my approach and before I could see what they were, 

 so I netted some and found them to be G. morsitans. With the exception of a 

 single specimen which settled on my dog, they made no attempt to obtain blood, 

 although there were a number of natives with me. Had I been walking through 

 grass, off the path, I should probably have been unaware of their presence. 



Distribution of G. palpalis in the Lado District. 



As will be seen from the attached map, G, palpalis was found on a large 

 number of khors in the Lado District of Mongalla Province. I believe it exists 

 on all the suitable khors in those parts of that district through which I passed, 

 with the single exception of the tract of land lying between the villages of chiefs 

 Hierallah and Miskeen. This tract is some 50 miles across, and is situated 

 partly in the Bahr El Ghazal Province and partly in Mongalla Province. It is 

 fairly high-lying and constitutes a water-shed, being peculiarly interesting from 

 an entomological point of view. It is the origin of many deep gorges which contain 

 small running streams, even at the end of the dry season ; and these ravines are 

 the habitat of several species of mosquitos which I have not seen elsewhere. 

 They are heavily timbered and there is also much rank vegetation under the 

 trees, consequently it is comparatively gloomy at the bottom of the gorges even 

 on bright sunny days. Every here and there the streams emerge from the ravines 

 and, shaded by trees and bushes, flow through open country, and in such places 

 they appear to be ideal abodes for G. palpalis. I spent many hours collecting 



