208 " DR. JAMES J. SIMPSON. 



VIII. Breeding Places and Habits of Glossina.! 



The two species of Glossina with which I was intimately associated during the past 

 tour were G. tachinoides and G. submorsitans, so that the following remarks apply 

 entirely to them. Zupitza and Yorke & Blacklock have given some details of the 

 breeding places of G. palpalis, but so far I do not think that any work has been done 

 on the two above-mentioned species in West Africa. 



On my arrival in the Northern Territories in September 1915 I established my 

 camp at Yapi, and studied G. tachinoides almost exclusively. Exhaustive searches 

 along the river bank during that time revealed only a few empty pupal cases, but no 

 live pupae. Despite this fact, females kept in my laboratory produced pupae which 

 matured and developed in due course. The humidity was diminishing and the 

 temperature increasing during this period, and it was found that as this took place 

 the pupal period diminished. The longest time taken by a pupa to hatch was 49 

 days, and some pupae deposited 25 days after these developed before them. The 

 shortest time taken by a pupa to develop was 22 days. From the pupae deposited 

 in September only 41 per cent, came to maturity, while of those deposited in November 

 87 per cent, produced adults. Males and females appeared in practically equal 

 numbers, but the males died off much more quickly than the females. The mortality 

 amongst the males was 35 per cent., amongst the females only 17 per cent. These 

 numbers refer solely to those which died before taking a meal. In January I made 

 an examination of the river between Yapi and Yeji, and again I searched assiduously 

 for pupae at various places, with the same result. I returned to Yapi on 22nd 

 February, and remained there till the 23rd March. During this period I obtained 

 447 pupae of G. tachinoides. Of these 392 produced adults (189 males and 203 females) 

 and none were parasitised. 



The breeding places of G. tachinoides seem to agree fairly closely with those of 

 G. palpalis. Zupitza, at Duala in the Cameroons, found pupae in the angles of leaf- 

 sheaths of palms. Yorke and Blacklock never found them there in Sierra Leone, but 

 they found them on the ground around the bases of palms. No palms exist at Yapi, 

 but between Kofaba and Yapi Borassus palms are fairly abundant in some places. 

 A careful search in both positions at these places failed to reveal pupae of 

 G. tachinoides. 



The most common situation for the pupae of G. tachinoides is in the decaying 

 humus beneath overhanging trees, in places which are quite sheltered from heavy 

 rains and which would be moistened only occasionally by water dripping down. 

 The sun seldom or never penetrates to such positions, and the ground is never really 

 dry. Although this species is very abundant amongst tall grass, I have never found 

 breeding places in such localities, nor have I found them in places which are liable 

 to be flooded at any period of the year. On these occasions I found pupae in hollows 

 of decayed trees, and a more common position is in a collection of decaying leaves in 

 the axils of branches, or in a similar collection at the fracture of a branch which had 

 become partly detached. 



On my return to Yapi on 31st May another search was made, and between this date 

 and the 11th June, 217 pupae were obtained. From these 87 females and 93 males 

 emerged. 



