CO885-(26N14) — Page 443

£ s. d.

Export of Parasites

£9,847 17 0

13,560 11 10

Balance of Tropical African Fund Balance of Bureau Fund ..

819 8 10 2,893 6 0

£13,560 11 10

13,560 11 10

62028

No. 46.

351

145

arduous and hazardous nature of the work carried out by all concerned, which has On the conclusion of this undertaking I think it right to bring to notice the entailed much strenuous exertion in addition to the study of the problems under exceptionally trying circumstances, principally on the part of Mr. Jack, but also by all those specially engaged for this work, amongst whom should be mentioned Captain Brereton, Mr. de Buys, Corporal Pettit, and Corporal Kemp. That there was a grave risk was demonstrated by the regretted death from sleeping sickness of the wife of one of the hunters. The unhealthiness of the locality otherwise and the rough and trying conditions under which the work had to be done are notorious. Much credit is therefore due to all associated in this task, especially to Mr. Jack, for the way he has conducted his investigations.

In agreement with him all arrangements have been made and instructions issued for the termination of the operations in the experiment area on 15th instant.

ERIC A. NOBES,

Director of Agriculture.

DEPARTMENT OF THE ADMINISTRATOR, SOUTHERN RHODESIA, to THE BRITISH SOUTH AFRICA COMPANY.

(No. X.830.)

(Received in Colonial Office 16th December, 1922.)

Department of the Administrator, Salisbury, SIR,

10th November, 1922. (Received 5th December, 1922.) I AM to forward, for the information of the Board, the attached copy of a minute by the Director of Agriculture and a report by the Chief Entomologist on the conclusion of the experiment for the extermination of tsetse fly by the destruc- tion of game in the vicinity of the Gwaai and Kana Rivers.

TREASURER,

I am, &c.,

J. RÓBERTSON, Secretary, Department of Administrator.

Enclosure in No. 46.

3rd November, 1922.

Department of Agriculture, Salisbury,

Tsetse Fly.

IN forwarding this report by the Chief Entomologist on the experiments in connexion with game elimination on the Shangani River, I have to point out that these operations have now been conducted over four seasons and have established the connexion between the quantity of fly and the prevalence of game beyond dispute; also the practicability of influencing the one through the other. The experiment as such may now therefore be brought to a conclusion.

The experiment has shown that the local reduction of game is accompanied by a corresponding diminution of the tsetse fly, and that where these operations have been in progress the advance of the fly has been checked.

The scheme of establishing a cordon of small areas on the edge of the fly belts in which, under adequate control, selected individuals are granted special shooting privileges has also been tested this year, and the results taken in conjunction with the observations made in the experimental area warrant the adoption and con- tinuation of the system as a definite policy of Government in fighting this grave rational danger.

These scientifically conducted investigations, as a perusal of the periodic reports show, have clearly demonstrated certain fundamental facts and laid down the principles on which administrative measures may be taken for the protection of extensive regions at present exposed to the risks of invasion by tsetse fly. In this way native reserves, farming areas and tracts of unalienated land can now be pro- tected, and the advance of the fly checked by measures in themselves practicable and inexpensive.

Agricultural Laboratory, Salisbury,

20th October, 1922.

Game Elimination Experiment: October, 1922. DIRECTOR OF Agriculture,

:

I HAVE the honour to report that with a view to making an inspection of the area of operations as above, I left Salisbury on the 27th September, returning on the 13th instant.

As in the past, I was able to carry out the inspection before any great amount of rain had fallen so that the observations made may be regarded as being as closely parallel with those of previous years as is possible in practice.

Game. There appeared to be considerably more big game present in certain parts of the area than in October last year. This was stated to be due to a great influx of game during August and September. The rigour of the drought would doubtless be responsible for an increased tendency on the part of game to concentrate in these comparatively well-watered parts.

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Although the fact that the operations were somewhat disorganized September last year certainly influences the figures, it is significant that considerably more than double the number of animals were destroyed in September this year than in the corresponding month last year. In fact the three completed months of the present year give the highest figures recorded during the operations, not excluding the first year, and the analysis of the figures shows that the increase is due mainly to the larger ungulates. This remarkable fact is probably due to a combination of several factors, namely: (1) The general unprecedented drought: (2) the cessation of shooting for six months prior to the commencement of operations this year; (3) the effect of shooting in the "concession areas" further up the Shangani in driving the game down again, and (4) the fact that several of the hunters have apparently gone rather far afield after game, notably up the Mzola River.

The figures in question are as follows:-

1919

1920

1921

1922

Game Destroyed in Game Elimination Experiment. -

Total for

July.

August.

September.

three months.

209

309

307

825

83

147

196

426

121

188

114

254

309

311

421 874

This increase of game is disappointing from the point of view of the experiment

and notwithstanding the fact that the animals have been persistently harried within the area there can be no doubt that in certain parts at least food supply of the fly has been to some degree auginented, and that had conditions developed this season as a normal sequel to the operations of the previous three years even better results inight have been recorded in respect to tsetse fly.

Tsetse Fly. Notwithstanding the increase of game recorded in the last section fsetse fly was found in general to be scarcer than last year, although slight increase was recorded in certain spots. In view of the reinvasion of the area by "big game," I was on the whole satisfied with the position as regards "fly." and would

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