. A practical study of malaria. Fig. 27.—Breathing syphons of (a) anopheles and (b) culex pupae. This necessitates a change in position, the abdomen hangingand rather curved around the cephalo-thoracic segment. Theeighth abdominal segment bears a pair of broad paddles forlocomotion. The young pupa is rather light in color, butrapidly becomes darker. The pupae are more easily alarmed than the larvae, and whendisturbed dart wildly downward with rapid jerks. Being oflower specific gravity than the water, they rise quickly withouteffort. They do not eat. Italian investigators1,15 observed that the
. A practical study of malaria. Fig. 27.—Breathing syphons of (a) anopheles and (b) culex pupae. This necessitates a change in position, the abdomen hangingand rather curved around the cephalo-thoracic segment. Theeighth abdominal segment bears a pair of broad paddles forlocomotion. The young pupa is rather light in color, butrapidly becomes darker. The pupae are more easily alarmed than the larvae, and whendisturbed dart wildly downward with rapid jerks. Being oflower specific gravity than the water, they rise quickly withouteffort. They do not eat. Italian investigators1,15 observed that the nymphae of somemosquitoes resisted freezing and dessication to a remarkabledegree. Enclosed for several hours in ice, they were yet ableto develop, and kept in dry soil for two or three days theydeveloped when placed in water. The duration of the pupal stage is ordinarily from two tofive Fig. 22.—Young culex larva. Magnified.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmalaria, bookyear1909
