SI 6 • Malaria 



2. Wing scales small, narrow, and lanceolate. Only 



a few scales on palpi Myzomyia. 



3. Large inflated wing scales Cyclohpteron. 



2. Scales on head and thorax. Scales narrow and 



curved. Abdomen with hairs, not scales. 

 1. Wing scales small and lanceolate Pyretophorus. 



3. Scales on head, thorax, and abdomen. Palpi covered 



with thick scales. 



1. Abdominal scales on ventral surface only. Thoracic 



scales like hairs. Palpi rather heavily scaled. . . . Myzorrhynchus. 



2. Abdominal scales narrow, curved or spindle 



shaped, in tufts and dorsal patches Nyssorrhynchus. 



3. Abdomen almost completely covered with scales 



and also having lateral tufts Cettia. 



4. Abdomen completely scaled. AldricMa. 



Species of the genera Anopheles, Myzomyia, and Myzorrhynchus, are known 

 to transmit malarial parasites. The Culicinae include Stegomyia and Culex, 

 1 which have some medical interest, as the former transmits yellow fever and the 

 latter, filarial worms. 



CULICIN^ 



I. Posterior cross-vein nearer the base of the wing than the mid-cross-vein. 



1. Proboscis curved in the female Psorophora. 



2. Proboscis straight in the female: .\ 



A . Palpi with three segments in the female. 



a. Third segment somewhat longer than 



the first two Culex. 



b. The three segments are equal in length. . . Stegomyia. 



B. Palpi with four segments in the female. 



a. Palpi shorter than the third of the pro- 

 boscis. Spotted wings Theobaldia. 



6. _Palpi longer than the third of the probos- 

 cis. Irregular scales on the wings .... Mansonia. 



C. Palpi with fine segments in the female Taniorrhynchus. 



II. Posterior cross-vein in line with the mid-cross-vein .... Jobloiina. 



III. Posterior cross-vein further from the base of the wing 



than the mid-cross-vein Mucidus. 



Male mosquitoes can at once be recognized by the pennate 

 antennae which appear like plumes on each side of the head. They 

 commonly "swarm" in flocks, do not suck blood, and are not com- 

 monly found in or about human habitations. Comparatively httle 

 is known of their habits. Cohabitation of the sexes occurs but once 

 after which the males commonly die. The females after fecunda- 

 tion require a meal of blood before they become gravid and ready to 

 oviposit. Oviposition takes place in water. During the winter 

 many gravid females hibernate in cellars in a very inactive condition, 

 but are immediately ready to fly to appropriate places and lay their 

 eggs with the return of warm weather. In hot climates some of 

 them estivate — i.e., become similarly inactive during the dry 

 period, but are ready to fly to the water and oviposit as soon as the 

 rains begin again. The breeding places vary with the species. 

 Fresh water is the usual preference, but a few select pools of brack- 

 ish water, and one or two species prefer salt water. Most of the 

 malaria-bearing species of anopheles prefer pools of fresh clear 

 water, some prefer running water in small streams with a slow cur- 

 rent. A few breed in large rivers. Some species are notably domes- 



