YELLOW FEVER PROPHYLAXIS IN NEW ORLEANS ii 



however, that it was originally imported into the Southern United 

 States from the Tropics through the medium of commercial inter- 

 course. It is common on the coast towns along the Gulf, the 

 Caribbean Sea, and on the Atlantic Coast of tropical and sub-tropical 

 South America, as well as in other tropical and sub-tropical countries. 



It is, therefore, a mosquito of the seaports, and this is one of the 

 reasons why it is so essential to eradicate it, especially in view of the 

 continual opening of new fruit ports in Central America and the West 

 Indies. It is capable of flourishing over a wide area, and Dr. Howard, 

 of Washington, states from collected observations that the species 

 can flourish wherever the sum of the mean daily temperatures above 

 6°C. (43°F.) throughout the year does not fall below io,ooo°C. It 

 is not exclusively confined to the coast line, observation showing that 

 in places where it is capable of surviving the winter, it readily spreads 

 into the interior, following the trade routes, whether rail or river. It 

 has already, it is stated, reached an altitude of 4,200 feet in Mexico 

 (Yellow Fever Working Party, No. i, 1903), and, as shewn by the 

 great outbreak of Yellow Fever in the interior of Guatemala and 

 Spanish Honduras in 1905, it has well established itself along the 

 Puerto Barrios and Puerto Cortez railroads. 



It is essentially a domestic mosquito, and, therefore, a mosquito 

 of cities. Whilst the malaria-bearing anopheles is now confined to 

 the outskirts of a large city like New Orleans, having been gradually 

 driven away from the centre of the town owing to the building up of 

 inhabited blocks, and to drainage, the Stegomyia, on the contrary, 

 seeks the central and more crowded parts of the City, the places, in 

 fact, where it finds the necessary and innumerable water receptacles 

 in the closest proximity to the dwelling houses. The knowledge of 

 this characteristic was of the utmost importance in the recent 

 epidemic. It is, indeed, a cistern-breeding mosquito, and is often 

 known on this account as the " cistern mosquito." It is found in 

 abundance, therefore, in those places where rain-water is collected 

 and stored for domestic purposes, no wonder, then, that it was present 

 in New Orleans with its sixty to seventy thousand water vats. 



The mosquito is readily recognised by the white bands upon the 

 legs and abdomen, the lyre-shaped pattern in white on the back of 

 the thorax, and the white spots on the sides of the thorax. It is due 

 to the presence of these bands and spots that this black and white 



