10 YELLOW FEVER PROPHYLAXIS IN NEW ORLEANS 



circulation in them, and they are rich in decomposing animal and 

 vegetable matter. They constitute the breeding grounds of several 

 species of Culex, of which the Commission found Culex pungens to 

 be one of the commonest. This mosquito is not, however, confined 

 to the gutters ; it is found along the river, in the marshes and in all 

 receptacles which can contain water. It is a very troublesome insect, 

 common all the year round, and bites in the evening and nighttime. 

 Other gutter breeders are Culex consobrinus and Culex siimulans. 

 Associated with this group is the water-closet mosquito, Culex 

 impiger, the larvae of which require highly-polluted water to thrive in. 



The Marsh Mosquitoes — Pools and Drainage Canals. 



These comprise, according to the same observers, certain species 

 of Culex and Anophelinae. Amongst the former are recorded C. 

 confirmatus, C. tceniorhynchus, and Grabhamia sollicitans. 



Culex tceniorhynchus is a marsh mosquito, and a virulent biter, 

 which often invades the City in large numbers and produces some 

 dismay on account of its resemblance, in its black and white banded 

 legs to the Stegomyia ; the body markings are, however, quite 

 different. 



The most widespread breeders in the marshes, and which come 

 only second to Stegomyia in their importance, are the Anophelinae. 

 As the Map II shews, they surround the City, being present 

 along the river front and in the marsh-land on the sides and in the 

 rear of the town. The Commission describes Anopheles maculipennis 

 as essentially a swamp mosquito, never becoming domesticated in 

 large centres of population, where dwellings are standing close 

 together and the soil drained. It exists in large numbers in the 

 outer districts of the City, but is only found in isolated instances in 

 the City. They state that it cannot exist in the cisterns. They 

 regard A. maculipennis as responsible for the tertian and quartan 

 varieties of malaria, and the A. crucians for the pernicious or aestivo- 

 autumnal fever. 



The Stegomyia fasciata. 



This mosquito, which has been conclusively demonstrated to be 

 the sole transmitter of Yellow Fever, is a very characteristic and 

 familiar one throughout the Yellow Fever zone. It is surmised. 



