CO885-(20-21) — Page 73

PUBLIC RECORD

OFFICE

༄། ། ། ། །

C.O.

Reference :-

885

20 PUBLIC RECORD OFFICE, LONDON

ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH-NOT TO

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at Kibwezi and Masongoleni Stations, a distance of 48 miles; there is, finally, an isolated patch recorded at Fort Hall. Fort Hall is situated two days' march from the Tana River, about 500 miles from its mouth; it is legitimate to suppose that all down this river the presence of Fusca will ultimately be noted. More informa- tion has been collected about the mile zone on either side of the railway line than about almost any other part of the country, and the limits of the Fusca patch would appear to be fairly accurately defined. Up to date, it has not been found south of Mtito Andei, nor north of Kibwezi. The character of these districts is altogether tropical, verging into the sub-tropical. Between Kibwezi and Simba, the country gradually changes into the more open park-like appearance of the rolling uplands. The altitude of Fort Hall is something over 4,000 feet, of Kibwezi 3,000 feet.

Dr. Ross has noted the fact that Fusca is most prevalent during the months of May and June.

Mr. Anderson, Veterinary Entomologist, gives the following note with regard to its bites:-

"It bites more noticeably between 3 and 5 o'clock in the afternoon, never, in my experience, during the hours of darkness. It frequents the little clearings and paths through the bush, squatting on the road, and always facing travellers. When disturbed it flies off a few yards, turns round, drops on the ground again in the same attitude."

Glossina pallipides is the most ubiquitous tsetse fly in the Protectorate, as a glance at the map will show. It is found all over the island of Mombasa, and on the adjoining mainland. On the railway its natural occurrence has not been reported in a locality with an altitude over 5,000 feet; thus from the coast it ranges up to the Athi River; on the other side of the mountainous barriers interposed between the Indian Ocean and the Victoria Nyanza, it has only been found at one spot down on the lake level. Dr. Ross notes its seasonable occurrence as greatest in August and September.

Glossina longipennis. The distribution of this fly in the railway belt is also clearly defined. Recently, what would appear to be a very wide area of distribution has been noted by Mr. Thomas, Veterinary Officer, extending from the Guaso Nyiro plateau along the caravan road to the frontiers of Abyssinia.

Unknown" flies are those reported by competent observers, but specimens of which have not been forwarded for identification. The one shown on the map on the Yala River is possibly the Palpalis, though, between it and the limits of the palpalis infection, a long stretch of the river has been searched with negative results. Those shown in the Taveta District are most probably Longipennis, and possibly Morsitans. Austin has recorded the presence of the latter at the back of Kiliman- jaro. South of Mombasa, on the coast, the flies are possibly Fusca. Unknown flies exist on the southern Guaso Nyiro, and in the Soudai Valley, east of Lakes Hanning- ton and Solai.

Glossina palpalis. The localities shown on the map represent the knowledge obtained up to the beginning of 1909. There is no tendency for this fly to spread outside its self-appointed boundaries. Much yet remains to be done in the way of determining how far up the rivers running into the lake Palpalis extends.

Accidental Occurrence of Flies.

Pallidipes has been captured on the platforms of both Nairobi and Naivasha, and at the latter Longipennis in addition. These were obviously imported by the railway. It is no uncommon thing, while the train is waiting at one of the stations in the fly belt during the night, for the compartment to be invaded by no less than all three species of Fusca, Longipennis, and Pallidipes, attracted by the lamp, and to find in the morning 150 miles further on two species still darting about.

A. D. MILNE,

Principal Medical Officer.

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