The prevention of malaria.

  • Ronald Ross
Date:
1910
Catalogue details

Licence: In copyright

Credit: The prevention of malaria. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    Cellia albimana.—Incriminated by S. T. Darling [1910], who found zygotes in thirty-six out of fifty insects and protoclasts and protospores in three. Occurs in Panama, Brazil, British Guiana and in the West Indies. Theobald (vol. iii. p. in) states that Dr St George Gray says that this Anopheline will bite at any time of the day or night; that the breeding-grounds are extremely varied, such as collections of water, especially full of reeds ; and records also that he has found larvae in brackish water in a lagoon shut off from the sea. He states, however, that he has never found the larvae in water barrels or similar receptacles in towns. Darling [1909, 1910] says that this and pseudo- punctipennis are the commonest mosquitos in the Panama Canal Zone, and breed in almost any terrestrial water. It carries both malignant and tertian malaria. Theobald, in his Mosquitos of Jamaica, also mentions rivers and large swamps and irrigation water, etc., as breeding- places. Cellia argyrotarsis.—S. T. Darling [1910] says that a zygote was found in one individual at Panama. Occurs in South America, the West Indies, Panama, but appears not to be an important carrier. From the records we gather that this is a less common species than C. albimana, to which it is very similar (possibly only a variety). Cellia pharoensis.—Newstead, Dutton and Todd [1907-1908] say that malaria parasites were seen to develop in this mosquito at Boma. The insect was common at Ismailia, and has been reduced simultaneously with malaria by operations since 1902 (section 53). Pressat [1905] considers it to be malaria-bearing, but gives no evidence. Occurs in East, West, Central and Northern Africa. It is recorded also from Palestine. Theobald (vol. i., 1901) says that this mosquito occurs during the month of April in Mashonaland and during January in Egypt. I found the larvae in small swamps of almost fresh water caused by seepage from the fresh-water canal at Ismailia, also in an ornamental fountain and in water-cress beds. Not seen in sewage cisterns. Willcocks say that it is a domestic mosquito, both in the larval and adult stages. The adults enter houses in order to obtain blood. In the open the females bite most viciously at sunset. The water in which the larvae live may be brackish. Larvae, in various stages of development, placed in water containing 1*78% common salt, die in less than twenty-four hours, but in water containing 1% common salt they live from two to three days, but become sluggish in their movements and appear to feed very little or not at all.