388 MOSQUITOES OF NORTH AMERICA 
larve, and for small collections of fluid, cesspits, etc., is highly effective, and 
though killing off most forms of animal life does not render the water as putrid 
or offensive as the use of oils. When fish are present these would be destroyed, 
and therefore this method is not advisable in larger collections of water.” 
SALT. 
During the 1905 outbreak of yellow fever in New Orleans an attempt was 
made to destroy mosquito larve in the open gutters of the city by the use of 
common salt. Dr. H. A. Veazie wrote us that the results were good where the 
work was properly done. Shortly after operations were begun there was a flight 
into the city of Aédes sollicitans from the salt marshes northeast of New Orleans. 
Indignant citizens ascertaining from experts the name and habits of the species 
jumped to the conclusion that salting the ditches had brought about suitable 
breeding conditions for sollicitans and that the invasion of the city by that 
species was a direct result of the work of the sanitary officials. 
ABOLITION OF BREEDING-PLACES OF HOUSEHOLD MOSQUITOES. 
In considering this question, just as in considering so many questions relating 
to mosquitoes, a complication arises from the diversity of facts concerning the 
life-histories of the different species of mosquitoes, facts discovered, for the 
most part, within the past ten years. At the time of the publication of Bulletin 
25, New Series, Division of Entomology, U. S. Department of Agriculture, in 
1900, the habits of but a very few species of mosquitoes were known and the 
generalizations drawn from the knowledge of these few species were altogether 
too broad and must now be greatly modified. The breeding-places of different 
species are quite peculiar. Those of the commonest household mosquitoes, 
namely Culex pipiens in the North and Culex quinquefasciatus and Aédes 
calopus in the South, correspond best with the generalizations formerly made, 
breeding as they do in every receptacle of water about residences, and the 
abolition of all such accumulations of water means their destruction. Where 
the rain-water barrel or the rain-water tank are necessary they should be 
screened. In New Orleans and other southern cities the boards of health are now 
enforcing the screening of these receptacles. The screening should be done with 
extreme care, a fine mesh screen being used and the fitting made very perfect. 
About a given house the waste places in the immediate vicinity should be 
carefully searched for tin cans, bottles, wooden or tin boxes in which water can 
accumulate, and all such receptacles should be destroyed or carted away. The 
roof-gutters of the building should be carefully examined, to make sure that 
they are not clogged so as to allow water to accumulate. The chicken-pans in 
the poultry yard, the water troughs for domestic animals, the water-cup of the 
grindstone, are all places in which mosquitoes will breed, and in them water 
should not be allowed to stand for any length of time. In the South the water 
accumulating under water tanks should be treated or drained away. The 
urns in the cemeteries at New Orleans have been found to breed mosquitoes 
abundantly. The holy-water fonts in Catholic churches, especially in the South, 
have commonly been found to breed mosquitoes; in some places sponges have 
