THE TSETSE PROBLEM IN NORTH MOSSURISE. 365 



Provided that the hiding-place itself afforded shade to the mother, overhead shade 

 (as an analysis showed) was a matter of complete indifference, and tho ground in 

 which puparia lay was commonly reached by the sun during part of the day. 



The puparia were usually close beneath the surface of the earth, and the evidence 

 suggested that the maggot had wandered but little from where it was dropped. 

 Under each log was usually harder ground, interspersed with softer pockets where 

 babblers (Craterojpus) or small mammals had previously scratched. The puparia 

 tended to be congregated in these pockets, but they appeared in some cases to give 

 evidence also of gregarious settling by their mothers. 



I carefully identified all logs, old or fresh, under which puparia were found and 

 was most interested to note that the very great majority of them were of two species, 

 chiwhanga and mukarati (Ormosia angolensis and Burkea africana), which were by 

 no means the commonest trees in the woodland. It was not that the fly chooses 

 these out, for all evidence (and there was a great deal) showed that it goes after 

 feeding to the nearest shelter, in some cases very diminutive. The reason was that 

 these are actually the commonest logs on the ground, and they are so because they 

 are the most durable timbers present and also do not readily burn. Some of these 

 logs had quite likely lain for twenty or thirty years, very gradually dwindling, whereas 

 a fallen Brachystegia may disappear in three. The eventual exploitation of those 

 areas will result in the early clearing out of these two useful trees (the Ormosia for 

 fencing posts) and the consequent confinement of the fly for its log breeding places 

 to species that are attacked by insects and burn. This is one of the various facts 

 that show how concentrated human activity assails the fly from several different 

 directions. 



The localisation of the breeding centres in this area suggests that the possibility 

 of attacking the fly on the lines suggested by Lamborn might require consideration. 

 Some of the logs at the Kanyezi vleis that were cleared by me of pupae at the end of 

 my first visit (early July) had already many fresh pupae under them when I came 

 back at the end of the month, where hartebeests had been present. Breeding was 

 going on both in June and July and in some quite cold weather, but emergences 

 from the pupae secured only began taking place in numbers with the advent of 

 really warm weather in early September, and continued into November, ^he 

 pupae, like those of Lepidoptera, will apparently stand a small amount of damage. 

 Out of 15 that 1 put aside as damaged in the finding on 30th July two afterwards 

 produced flies. 



Glossina brevipalpis. 



I obtained no live pupae of brevipalpis, but found a few batches of pupa-cases 

 in the Brachystegia bush on the Buzi east of Spungabera, one of which contained 

 nearly a hundred puparia. In the case of this fly the batches were beside lyifig 

 places of buffalos and wild pigs, and the flies at the moment of dropping the 

 maggot had in the biggest find (PL xiv, fig. I) evidently been resting for the 

 most part on the undersides of the coils of large rough lianas {Cissus, Landolphia 

 and Baukinia), apparently favourite resting places. Some of the puparia were 

 found under logs ?nd some of the replete gravid females taken during the bush-pig 

 incident (p. 337) were resting on the lower surface of fallen Uapaca sansibarica 

 (737) d2 



