The malarial fevers, haemoglobinuric fever and the blood protozoa of man . n easy method of differentiating them. An exceptionto this rule has been noted in a few Culicinae. The color of the larvae isusually gray, brown, or greenish. Anopheles larvae are not very resistant andare usually short lived although a few species have been known to hibernatethrough a long winter. The length of the larval stage varies in the differentspecies. In Myzomyia ludlowii the larval stage occupies from 9 to 10 days. 68 THE ETIOLOGY OF THE MALARIAL FEVERS. The Pupae.—The pupal stage lasts from a few hours to sev
The malarial fevers, haemoglobinuric fever and the blood protozoa of man . n easy method of differentiating them. An exceptionto this rule has been noted in a few Culicinae. The color of the larvae isusually gray, brown, or greenish. Anopheles larvae are not very resistant andare usually short lived although a few species have been known to hibernatethrough a long winter. The length of the larval stage varies in the differentspecies. In Myzomyia ludlowii the larval stage occupies from 9 to 10 days. 68 THE ETIOLOGY OF THE MALARIAL FEVERS. The Pupae.—The pupal stage lasts from a few hours to several days,depending upon the temperature. During this time the pupae are very active,constantly coming to the surface of the water to breathe, but as they are noteasily differentiated from the pupae of Culex, a detailed description is not con-sidered necessary. Fig. 19 gives a good general idea of the structure of thepupa. The Imagine.—When the time has arrived for the emergence of theimagine or adult insect, the pupa rises to the surface of the water, the skin over. Fig. 18.—Larva of Anopheles and , Larva of AnophelinEe. Note horizontal position in reation to surface of the water,and the absence of syphon (A). Larva of Culex. Note angular position in relation to surfaceof the w^ater, and presence of the syphon, at A. (Fig. i, after Howard; 2, after Theobald.) the thorax breaks open, and the perfect insect gradually emerges from the pupalcase, which serves as a resting place for it until its wings are dried and it is ableto take flight. Habits of the Anophelinae. Feeding.—As a rule, all Anophelinae arenight feeders, but it is not at all unusual to observe Anopheles, of various species,feeding in the late afternoon, and I have often seen Myzomyia funesta biting inthe early morning and even at noon in the tropics. During the daytime mostAnopheles hide in the woods or beneath the leaves of bushes and small trees orin dark corners of houses or native huts in the trop
Size: 1573px × 1587px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectb, booksubjectmalaria
