Further reports (no. 4) on flies as carriers of infection.

Date:
1911
Catalogue details

Licence: In copyright

Credit: Further reports (no. 4) on flies as carriers of infection. Source: Wellcome Collection.

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    especially in the living rooms of cottages, and in the kit'chens of the larger houses. Through the agency of the village blacksmith, we had previously distributed a considerable number of wire-mesh 44 balloon ” traps ; and it was found that a London firm had also sent down to the village supplies of fly-papers and fly-tapes. By means of these appliances residents in the village had been successful in trapping large numbers of flies. In some instances where four or five tapes had been hung up in the same room only a few hours previously, all were found entirely covered with these insects, while some of the 44 balloon ” traps were 44 humming” with the movements of hundreds of living flies. There was, however, agreement on all hands, that the flies had considerably diminished in number during the previous fortnight, owing presumably to the lowered temperature and other changes in the meteorological conditions. As some evidence of the excessive prevalence of the flies a week or two earlier, one woman informed us that she had had to drown the mass of flies caught in her 44 balloon ” trap, several times a day ; while another woman stated that, on one occasion, having left open the door on the sunny side of her cottage for about half-an-hour, the door-mat, in the course of that time, had become absolutely black with flies. AH the residents interviewed affirmed that never in their experience, during previous years, had they known flies to be present in such abundance, and that great difficulty had been experienced in protecting articles of food, more especially milk and sugar, from their invasions. Thanks probably to the continuance of cold and wet weather the number of flies more or less continuously diminished from the end of June, 1910. During a stay of several days at Postwick during the early part of August, one of us found the flies distinctly less numerous than on the occasion of former visits. As the result of careful investigation in the village itself, in which there existed no unusual accumulations of manure or other fermenting refuse, we came to the conclusion that no special oppor- tunity was afforded there for the breeding of the house-fly in such quantities as had been present, especially at so comparatively early a period of the year, since the Musca domestica, even under favourable conditions, does not usually begin to put in an appear- ance, in this country, before the beginning of August. (Vide Memorandum by Mr. E. E. Austen, postea.) It became obvious, therefore, that special conditions must be in operation, affording a reservoir of flies at some situation outside the village boundaries. Such conditions were afforded by the presence of enormous accumulations of dust-bin and other refuse deposited by the Norwich Corporation on the Whitlingham Marshes, at a distance of a little over half-a-mile from the village church. Our object was therefore to ascertain— Whether the plague of flies at Postwick was directly due to the presence of this refuse heap, and, if so, whether the flies were being attracted from the surrounding country by the very penetrating smell of the heap, or distributed from it as a breeding centre. 19193 A 2