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.

    13/52 (page 11)
    2.—Memorandum on the Result of Examinations of Flies, etc., from Postwick village and refuse deposit ; with A Note on the Occurrence of the Lesser House-Fly at Leeds. By Ernest E. Austen, F.Z.S. The flies, etc., from Norwich and Postwick, forwarded July 15th, duly reached me on the 16th instant. Below, I give the result of my examination of this material, which, for convenience sake, I refer to under the receptacles in which the different portions of it were contained. The net (flies caught at the refuse deposit) enclosed some 300 Musca domestica, and about 20 Fannia {IIomalomyio) canicularis— the latter all males. Tubes:— “ Workman’s hut at refuse-heap. July 14th ”— 3 Musca domestica (2 males), 1 female (latter arrived alive, males both dead). 1 Fannia (IIomalomyia) canicularis : dead. “ Fishergate Depot, Norwich, July 14th, 1910”— 1 Musca domestica, female (alive). “ Postwick Hall, dining room, July 14th, 1910 ”— 2 Stomoxys calcitrans, L. (both dead). Boxes:— From refuse, fresh deposited, July 14th”— 2 live larvae, not Musca domestica or Fannia, probably Calliphora or Sarcophaga. “ Dead flies from workman’s hut, July 14th ”— 3 Fannia canicularis (all males). 1 Musca domestica, (female). “July 14th, 1910, from portion of heap deposited on July 11th”— 1 larva, 2 pupae, not Musca or Fannia. ? Stomoxys calcitrans. I may add that, as regards the material forwarded, on July 14th, by Mr. A. E. Collins, City Engineer, Norwich, the flies in a balloon trap, from the Smithy Cottage, Postwick, and those on a “ tangle- foot ” tape, from Postwick Hall Farm, were all Musca domestica. Under ordinary circumstances Musca domestica does not begin to be numerous until August, and in the course of last week, on fly- papers sent to me from Leeds (see Note appended), M. domestica was outnumbered by F. canicularis in the ratio of about 8 to 1. I am, therefore, decidedly of opinion that the excessive predominance of M. domestica at Postwick and in the vicinity {see “ The net ” paragraph above) points to the existence of some unusual condition, which has favoured the breeding of the Common House Fly.