492 Journal of the Department of Agriculture. — Dec, 1922. 



means that should be adopted for combating the disease and whether 

 conditions should be attached to the exportation of hides, skins, and 

 wool from countries where the disease exists. The committee will 

 report to a further conference. In the meantime more active steps 

 in this country are necessary. 



The spore vaccine manufactured at the Veterinary Research 

 Laboratory, Onderstepoort, is very effective and should be used 

 extensively and regularly. 



19. Tsetse Fly. — The life-history of species of this fly begun last 

 year is being continued in Zululand. The work has a twofold object, 

 one in relation to the disease known as nagana in live stock, and the 

 other in connection with similar investigations instituted by the 

 Imperial Bureau of Entomology in several parts of this continent, 

 including Rhodesia, in its relation to sleeping-sickness in man. 



20. Nagana. — Simultaneously with the study of tsetse fly by the 

 Division of Entomology, the Division of Veterinary Education and 

 Research is carrying out investigations in connection with nagana. 

 Much progress has been made. Mr. Curson, the officer in charge, 

 demonstrated that one of the remedies recommended, namely, tartar 

 emetic, reduced mortality to a very low figure. 



21. Horse-sickness. — The Director of Veterinary Education and 

 Research is able to report very beneficial results from an improved 

 method of inoculation, by Avhich he reduced the mortality among 

 horses treated at Onderstepoort to 2.5 per cent. The inoculation of 

 2413 mules was accompanied by a mortality of only about 1 per cent. 



22. Locusts. — A full report on the work of the year appeared 

 in the Journal, September, 1922. The infestation far exceeded anti- 

 cipations both as regards extent and severity. The reports received 

 by the Department, upon which a campaign is based and which are 

 relied upon, were meagre, and consequently the provision made in 

 aavance proved inadequate on a few occasions in the beginning of 

 the season. By the beginning of December, 1921, however, poison 

 was manufactured in sufficient quantities to meet all applications 

 promptly. It is regrettable that in many instances poison supplied 

 free is wasted either by individuals using larger supplies than are 

 necessary, or by application being made for larger quantities than 

 the situation demands. This is a matter, however, over which the 

 Department has no control, as it cannot take the responsibility of 

 reducing applications and being accused of delaying or hampering 

 destruction. 



The much more extended campaign last season is indicated by 

 ■the following comparison with the previous season : — 



1920-21. 1921-22. 



Number of districts infested 32 58 



Poison distributed (gallons) ... 12,990 92,675 



Number of swarms destroyed ... 27,100 118,662 



Large swarms of flying locusts spread over Bechuanaland and 

 the western Transvaal districts from the Kalahari. A good deal of 

 damage was done to crops, though many of these swarms were 

 destroyed. Flying swarms laid eggs over a large extent of country 

 beyond that upon which the campaign was waged last season. 



