NOTES ON THE YELLOW FEVER MOSQUITO 373 



NOTES ON THE YELLOW FEVER MOSQUITO, 

 STEGOMYL^ CALOPUS (FASCL'VTA). 



(oreyo"? = a house; jjLvia a fly.) 

 The S. calopus belongs to the CuHcales of the sub-family, 

 CuHcinse. 



On account of its wide distribution, domestic habits, vital tenacity 

 of its eggs, the different infections it is capable of carrying, yellow 

 fever in particular, it is one of the most formidable insects in existence. 

 They are small black mosquitoes, with bright whitish markings on 

 head or thorax, and bright w^hitish transverse marks on abdomen and 

 legs. They are common in all tropical and sub-tropical climates 

 between 40° N. and 40° S. from sea-level to nearly 3,000 feet high. 



THE ADULT FEMALE. 



The head is black with white markings not unlike a crown in shape; 

 the palpi are short, black, tipped with white. The scutum is brown, 

 with a lyre-shaped set of marks thereon. The scutellum is white. The 

 abdomen is blackish brown, with white transverse bands across the 

 dorsum and on the sides of the segments. The femora are black with 

 a white tip; the tibia black, the tarsus black with two to five white 

 bands. It has the common mosc|uito wing, with the third and fifth 

 long vein forked. 



The adult male is similar, but has long palpi, and does not bite man. 



HABITS. 



A house-haunting mosquito always. 

 Perhaps the commonest mosquito on board ship. 

 It bites in the daytime as well as at night. 

 It breeds close to human habitations. 



Its eggs are laid in anything that holds water — a sardine tin or 

 water-barrel. 



EGGS. 



Almost black, laid in seven batches, they stick closely together, 

 but not in rafts. They are very resistant; if kept dry they will remain 

 fertile for six months. 



The yellow-fever virus is transmitted to a second generation. 



LARY^E. 



Dark in colour, has a short, stout breathing tube and very large 

 tracheal gills. Laterally, on the eighth abdominal segment is a single 

 row of eight to nine scales like miniature arrow heads and a wisp of 

 three small hairs. It can remain submerged for a long time, and can 

 live in filthy water aided by its large tracheal gills. 



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