THE MOSQUITOES OF THE SOUTHEASTERN STATES 25 
some at any point the breeding source can usually be found on the 
premises or nearby. An essential part of any aegypti control program 
is the frequent and thorough inspection of premises by well-trained 
men. 
One of the most prolific sources of production for the southern 
house mosquito (Culex quinquefasciatus) in a city or town is the 
storm-sewer catch basin, which is designed almost universally with a 
watertight debris trap below the level of the outlet. The larvae of 
Aedes aegypti also have been found in these places. In an anti- 
mosquito program the catch basins are usually oiled periodically 
with special equipment installed on trucks or motorcycles. Other 
important sources of mass production of C. guinquefasciatus are open 
cesspools, badly drained street gutters, and polluted ground pools, 
especially around city dumps or sewage outlets. Wherever possible 
these breeding places should be eliminated permanently by drainage, 
or the cesspools effectively covered; otherwise they require frequent 
treatments with larvicides. 
Pyrethrum-extract emulsion has been recommended for treatment 
of polluted ground pools and sewage beds. Paris green will destroy 
the larvae in ditches, pools, and catch basins, although oil is usually 
preferred as its deters oviposition. The use of paris green for the 
control of both aegypti and quinquefasciatus larvae in artificial con- 
tainers has been discussed under Larvicides (p. 19). 
SALT-MARSH MOSQUITOES (PRINCIPALLY AEDES SOLLICITANS AND 
A. TAENIORH YNCHUS ) 
The salt-marsh mosquitoes fly extremely long distances. Migra- 
tory swarms have been observed 40 miles or more from their breeding 
places, although the average length of flight is, of course, much less. 
Because of their great flight range, local work against these species 
may be of little benefit, and control programs are usually undertaken 
on a county-wide basis. Generally, however, the actual control work 
should begin on the breeding marshes nearest the population centers 
and should progress outwardly until the desired results are obtained. 
Investigations and control work against the salt-marsh species were 
begun in New Jersey more than 30 years ago, and New Jersey’s exam- 
ple has been followed by most of the North Atlantic States. On the 
south Atlantic and Gulf coasts, except in a few counties in Florida, 
no large-scale operations had been attempted prior to 1933, when 
advantage was taken of the opportunity offered by the programs of 
the Federal Emergency Relief and the Civil Works Administrations 
(32, 47, 67, 93). Although this work was not long continued, many 
valuable experimental and survey data were obtained, and these 
have been useful in a number of counties that have since become en- 
couraged to provide funds for continuing the operations. 
Mosquito-breeding conditions in salt marshes and the methods em- 
ployed to overcome them are extremely varied. In general, the 
mosquitoes breed on the parts of the marsh that are not covered 
by daily tides, usually in pot holes and depressions of various sizes, 
but sometimes over extensive level areas. By the usual control prac- 
tices a system of ditches (pl. 4) is installed (1) to provide for a 
fairly rapid run-off of surface water following the occurrence of 
