MOSQUITO WORK IN KHARTOUM, ETC.

Lado .Mansonia uniformis.

River banks high. Swampy Culex viridis.

island. Bush country be- Culex fatigans. yond. Myzorhynchus paludis.

Mimomyia uniformis. M} Tzomyia ? It will be seen that several genera previously unrecorded from this part of Africa have been found, such as Mucidus, Taeniorhynchus, Theobaldia, Uranotaenia and Mimomyia,1 while several entirely new genera and species have been secured.2

The White Nile, as might have been expected, was found to haTbour many more Anophelines, than the Blue Nile, though the Blue Nile furnishes a good many fever cases in the summer months. Myzorhynchus paludis was very common on the Pibor, where Uranotienise were also in large numbers, and were very vicious. On the Bahr-El-Jebel Myzomyia funesta, in both its varieties, was a frequent visitor in the evenings. This mosquito was found to remain on board for several days at a time, lying perdu in the folds of curtains and hangings, in mats and carpets bestowed in heaps, and finding special sanctuaries on the under surfaces of tables.

The steamer on which the captures were made was prevented becoming a breeding ground, and so any fallacy which might have arisen from this source of infection, was obviated. Mr. Young, the engineer, rendered every assistance in his power.

Mansonia uniformis is, however, par excellence, the mosquito of these parts of the Niles, i.e., the Blue Nile from Wad Medani to Roseires, and the White Nile from Renk to Gondokoro, including the Sobat River and Lake No. In the light of this fact it would be well to ascertain if filariasis is common in these regions. It was on this blood-loving insect that a small red tick looking like a tiny preserved cherry was first found. This tick was afterwards discovered on

Myzorhynchus paludisJ and on several other species. It does not seem to affect the mosquito in any way, and was usually attached to the thorax or abdomen. I have also once seen what seems to be a green tick. So far, there has not been time to study these parasites more fully, but specimens have been sent to Mr. Theobald.

In connection with preventive methods to be adopted at stations in the swamp regions of the White Nile, one would strongly advocate the introduction of sun-flower cultivation. Apart from its water-absorbing capacities the sun-flower is of great value as an economic product, the oil, seeds, and fibre all being useful. It has been successfully cultivated in the previously malarial stretches of the Mississipi valley, and is known to grow well and rapidly in the Sudan.

As far as the application of culicifuges goes I have found a mixture of equal parts of citronella oil and absolute alcohol, the most effective preparation, and one pleasant to employ.

New genera and species

Permanence of Anophelines on steamers

The mosquito tick

Sun-flower cultivation advocated

1 Theobald. Monograph of the Culicidse, Vol. iii. 2 Vide special report by Mr. F. V. Theobald