Filariasis and elephantiasis in Fiji ; being a report to the London School of Tropical Medicine.

  • Manson-Bahr, Philip Heinrich, Sir, 1881-
Date:
1912
Catalogue details

Licence: In copyright

Credit: Filariasis and elephantiasis in Fiji ; being a report to the London School of Tropical Medicine. 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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    Culex fatigans (Wied) was bred in the laboratory all the year round but more sparingly, however, during the cool season. Larvae were found in a dark fresh-water tank, in kerosene tins and in artificial breeding- pools, placed round the laboratory. It is a purely night-feeding species. Culex jepsoni (Theob.) (Coloured Plate V.). Another new species determined from specimens sent to England early in 1910. I found it breeding in open sheets of water. When alive, it is easily distinguished from Culex fatigans by its marked banded proboscis. It is a large, heavy mosquito, feeding equally well both night and day. C. fatigans and C. jepsoni feed well in captivity on banana, apple, etc., but considerable difficulty was experienced in starving them to the right degree of voracity that ensured their feeding on blood. F inlay a poecila (Theob.) appeared at night sparsely in March, and again in September and October. A very shy-feeding species, and only females were found. I never succeeded in breeding it from the larva. Stegomyia fasciata (Fab.) was bred from larvae in the laboratory. It is a rare mosquito in the country in Fiji, but common in the town of Suva. Captive specimens fed equally well both day and night. Culex nocturnus (Theob.), a species only described from Fiji. It is recog- nizable by its banded legs and abdominal markings. It bred sparingly in stagnant water round my house, but never in numbers sufficient for experiment. Phoniomyia (prox. nitidiventer) (Giles) was hatched out in quantities from larvae found in an old kerosene tin in April, 1910. The imagines were all females. No males were ever seen. It was never met with again. Mosquito as an Intermediary of the Filaria. I made a series of observations on the development of the filaria in the mosquito in the following species. Only mosquitoes bred in captivity, and only no periodicity microfilariae were employed :— Culex fatigans ; Stegomyia pseudoscutellaris ; Stegomyia fasciata ; Culex jepsoni. In making these experiments in order, so far as possible, to obtain uniformity of conditions, certain precautions were necessary. The Temperature of the Atmosphere. Appendix XII. gives the average mean, maximum and minimum temperatures during the months in which the experiments were pursued. It will be gathered from this that the very limited range of temperature experienced in Fiji has little influence in determining the actual develop- ment of the filaria in the mosquito. The temperature was higher in May and June, when the main work with Culex fatigans, Stegomyia fasciata and Culex jepsoni was undertaken, than in August and September, when the first experiments with Stegomyia pseudoscutellaris were begun. The number of Microfilariae in the circulation favourable FOR Experiment. To ensure success it was found that the microfilaria infection had to be neither too small nor too large. In order to arrive at the optimum degree of infection certain experiments had to be made. An estimate