MOSQUITOES. 249 



Differentiation of Culicinae Genera. 



i. Posterior cross- i. Proboscis curved in female. Psorophora. 

 vein nearer the 2. Proboscis straight in female, 

 base of the wing A. Palps with 3 segments in the female. 



than the midcross- 



vein. 



a. Third segment somewhat longer than the 

 first two. Culex. 



b. The 3 segments equal in length. Stegomyia. 



B. Palps with 4 segments in the female. 



a. Palps shorter than the third of the proboscis. 

 Spotted wings. Theobaldia. 



b. Palps longer than the third of the proboscis. 

 Irregular scales on wings. Mansonia. 



C. Palps with 5 segments in the female. Tcenior- 

 hynchus. 



2. Posterior cross-vein in line with midcross-vein. Joblotina. 



3. Posterior cross-vein further from base of wing than midcross-vein. Mucidus. 



Of the Culicinae the genus Stegomyia is of importance on account 

 of yellow fever. The totally efficient hosts for filariasis (filarial 

 embryos found in thorax and proboscis) are chiefly among the genus 

 Culex. The genera Mansonia and Taeniorhynchus may also trans- 

 mit filariasis. Some think the Anophelinae genera "Cellia" and 

 "Myzomyia" may transmit filariasis as well as malaria. 



The genus Culex is implicated in dengue. 



Stegomyia. This is the most important culicine genus. These 

 are mosquitoes with silver markings. The head, entirely covered 

 with flat scales, has also some upright forked scales. Scutellum has 

 dense flat scales. S. Calopus is deep blackish-brown with two thoracic 

 parallel lines with curved silver-white lines outside. Banding of 

 thorax, abdomen and legs. 



Culex. Male palpi long and acuminate. Head has narrow 

 curved and upright forked scales. Laterally, flat scales. C. fatigans 

 supposed to carry dengue. 



Theobaldia. These Culicinae have spotted wings resembling 

 Anophelinae. These spots are due to aggregations of scales, not to 

 dark scales. Male palps are clubbed (like Anopheles). 



Mucidus. This genus has a mouldy look from long twisted gray 

 scales. 



Mansonia. This genus is characterized by broad flat asym- 

 metrical wing scales. 



