Report of the Principal Civil Medical Officer and Inspector-General of Hospitals / [Ceylon].

  • Ceylon. Civil Medical Department.
Date:
[1924]
Catalogue details

Licence: Public Domain Mark

Credit: Report of the Principal Civil Medical Officer and Inspector-General of Hospitals / [Ceylon]. Source: Wellcome Collection.

    72/78 (page 58)
    (15) Hind legs with the last three tarsal segments entirely white; palpi in female with three white rings the second narrow and widely separated from the apical ring (jamesi Theob). Hind legs with the tip (last segment) only white; palpi in female with three white rings, the apical ones broad and narrowly separated {maculatus Theob). (16) Hind legs with a very broad white band covering the tibiotarsal joint (leticosphyrus Don). Hind legs without such a band {punctulatm var. tessellatus Theob). Synopsis of the Mature Larvas. (1) Shaft of antenna with a branched hair, or if absent the post-antennal hairs short and inconspicuous. (Sub-genus Anopheles). Shaft of antenna without a branched hair, the post-antennal hairs always long and conspicuous. (Sub-genus Myzomyia). (2) Shaft of antenna without a branched hair, post-antennal hairs small ; thorax and abdomen completely covered with minute curved setae [annandalei Pras). Shaft of antenna with a branched hair, post-antennal hairs large ; thorax and abdomen without setae. (3) Outer clypeal hairs witha few short branches, or simple; hair on antenna arising near base of shaft. Outer clypeal hairs thickly branched dendri form; hair on antenna arising near middle of shaft. (4) Thoracic palmate hair vestigial with four or five hair-like divisions ; abdominal palmate hairs with leaflets terminating bluntly ; large species (7 mm.) {gigas Giles). Thoracic palmate hair well-defined with several (10-14) narrow leaflets ; abdominal palmate hairs with leaflets terminating in definite filaments or very sharp points ; small species (3*5 mm.).. . 6. (5) Inner and outer clypeal hairs branched, the former usually bifurcating before the middle (aitkeni James). Inner and outer clypeal hairs simple {aitkeni var. insulaeflorum Swel). (6) Innermost sub-median anterior thoracic hairs branched (6*8 divisions) from or near the base ; black with white markings {barbirostris Wulp). Innermost sub-median anterior thoracic hairs simple, or with two or three very short branches arising on the distal portion of the stem ; yellowish-green or yellowish-brown without definite white markings (hyrcanus Pall). (7) Abdominal tergal plates very large, occupying from nearly one-half (first segment) to almost the whole (eight segment) of the dorsal surface of the segments Abdominal tergal plates smaller, those on the anterior segments reduced to narrow transverse bars. (8) Inner and outer clypeal and pre-antennal hairs simple, or (intermediate form) with a few short branches, those on the pre-antennal hairs arising at intervals along the stem {funestus var. listoni List). Inner and outer clypeal hairs with more numerous short branches, pre-antennal hair branched (5 or 6 divisions) from the base {funestus var. aconitus Don). (9) Outer clypeal hairs simple, or with a few short branches only ; pre-antennal hairs simple, or with faint lateral branching. Outer clypeal hairs thickly branched, plumose ; pre-antennal hairs branched, usually from the base (10) Inner and outer clypeal hairs simple, or the inner only with fine short, lateral branches ; thoracic palmate hair (except A. subpictus) small, but with definite leaflets. Inner and outer clypeal hairs with short lateral branches ; thoracic palmate hair with hair-like divisions only (11) Anterior clypeal and pre-antennal hairs always simple ; leaflets of abdominal palmate hairs ending in long filaments. Inner clypeal hairs usually with short branches ; leaflets of abdominal palmate hairs ending in blunt points. (12) Thoracic palmate hair vestigial, with long hair-like branches ; sub-median thoracic hairs scarcely pigmented, the innermost without a conspicuous dark root ; antennae feebly chitinized, unpig- mented. Thoracic palmate hair small, but with six to eight short leaflets ; sub-median thoracic hairs powerful, pigmented, the innermost with a conspicuous dark root ; antennae strongly, chitinized, the tips dark {culicifacies Giles). (13) Pre-antennal hairs situated below or outside the inner clypeal hairs ; outer clypeal hair long -from f to I the length of the inner {subpictus Grassi). Pre-antennal hairs sitiiated between the inner clypeal hairs ; outer clypeal hair very short—J or less the length of the inner {subpictus var. vagus Don). (14) Innermost sub-mediananterior thoracic hairs short, with two or three branches (occasionally simple) without conspicuous roots {punctulatus var. tessellatus Theob). Innermost sub-median anterior thoracic hairs large with numerous branches and conspicuous roots, {leucosphyrus Don). (15) Extremities of leaflets of abdominal palmate hairs sharply pointed or filamentous {maculatus Theob). Extremities of leaflets of abdominal palmate hairs bluntly pointed {karwari James). (16) Vertical clypeal hair long and simple, occasionally bifid ; leaflets of palmate hair on first abdominal segment very narrow, usually hair like, 7—8 in number {jamesi Theob). Vertical clypeal hair short, with four or five branches arising, usually, from the base ; leaflets of palmate hair on first abdominal segment differentiated, 10-12 in number {fuliginosus Giles). The Relation of Paddy Cultivation to Malarial Endemicity.—Investigations in this connection were conducted at several towns situated in different parts of the Island with a ^iew to determining the effects of varying conditions upon the Anophehne fauna of the rice fields, and the relation of the latter to the incidence of malaria ; they were commenced in August, 1922, and continued until November, 1924. The area under paddy at the centres selected varied considerably—from approximately 30 to several hundred acres. At each centre from 10 to 30 fields (varying in total area from one to three acres), situated in three or more blocks in different parts of the town were selected, mainly in accordance with their position in relation to dwellings and irrigation channels. Examinations for Anopheles larvae were made each month ; they were not restricted to the rice fields alone, but included uncultivated fields, irrigation channels, swampy areas and pools produced by seepage, and various other types of potential breeding places in the vicinity. For the purpose of