A monograph of the Anopheles mosquitoes of India / by S.P. James and W. Glen Liston.

  • Sydney Price James
Date:
1904
Catalogue details

Licence: In copyright

Credit: A monograph of the Anopheles mosquitoes of India / by S.P. James and W. Glen Liston. Source: Wellcome Collection.

    150/238 (page 112)
    Characters distinguishing this mosquito from other species,— Prom A. stephensi it is distinguished by the absence of scales on the abdomen, by the markings on the palpi, and by the absence of speckling of the legs. This mosquito might be confounded with those of Group II, especially with punctulatus, but an examination of the palpi would prevent any error, for the members of that group have four bands on the palpi. This mosquito very closely resembles costalis but differs from it chiefly in the fact that costalis has a white interruption in the black area on the first longitudinal vein, opposite the penulti- mate black costal spot, and has three black spots on the sixth longi- tudinal vein in place of two. These, however, are merely colour variations and can hardly be considered of specific value. We can confirm Colonel Giles’ statement that there is a tuft of white scales on the front of the thorax as well as a small patch of spindle-shaped scales on the last abdominal segment. Mr. Theobald apparently considers that these scales are absent, and for that reason has placed the species in the genus Myzomyia. A classification based upon characters about which it is possible for so much difference of opinion to exist, cannot, we think, be considered a very useful one. We may here refer to a specimen which Mr. Theobald has placed as the type of a new genus Aldrichia. This genus is based on a single specimen, which was found among the types of A. rossi deposited in the British Museum. It differs from all other ‘‘ ano- pheles ” in the fact that the entire dorsum of the abdomen is cover- ed with flat imbricated scales arranged exactly as in mosquitoes of the genus Culex, In other respects the specimen, which has been named Aldrichia error, appears to resemble rossi very closely, and Colonel Giles is of opinion that in all probability it represents merely an abnormality. He states that when examining a number of specimens of culicifacies he came across one the abdomen of which was similarly scaled (see his description cf this species. Hand- book, 2nd Ed., p. 317, and his Revision of the Anophelina3, pp. 9 and 29), so that observers should certainly be on the look out for specimens presenting this curious character, in order that the question as to whether such specimens are abnormalities or not may be cleared up. 112]