28 MISC. PUBLICATION 336, U. S. DEPT. OF AGRICULTURE 



ity, excessive lowering of the water table may be avoided in some 

 cases by the use of very shallow ditches- 



Larvicides are employed in salt-marsh-mosquito control for the 

 treatment of areas that are not taken care of by the ditching system. 

 Fuel oils are used extensively for this purpose and are usually ap- 

 plied with a knapsack sprayer. It has been found that the heavier, 

 less volatile oils are harmful to wild birds, fish, and other aquatic 

 animals, and it is therefore recommended that only relatively volatile 

 oils, such as No. 2 fuel oil, be used in treating mosquito breeding areas 

 where wildlife is likely to be affected. The pyrethrum-extract emul- 

 sion as described on p. 21 is highly recommended where wildlife is 

 concerned. Paris green has given promising results against salt- 

 marsh Aedes larvae, and is more economical than oil in labor, mate- 

 rial, and transportation costs, in addition to being much less disagree- 

 able to handle. It is mixed with water and sprayed over the breeding 

 area with a sprinkling can having a capacity of 3 or 4 gallons. Two 

 gallons of water will cover about 1,250 square feet and should con- 

 tain about 1 ounce of paris green for an application at the rate of 

 2 pounds per acre. For use in shallow water and with even distribu- 

 tion the amount of paris green can be reduced by at least one-half. 

 The water used is dipped from the breeding place as needed. It 

 should be strained, if necessary, to prevent clogging of the sprinkler 

 head with trash. 



NOTES ON THE GENERA AND SPECIES 



The genera and species are discussed in the following pages. As 

 few mosquitoes are known by common names, the scientific name 

 will be used to designate the kind under discussion. 3 During the 

 early years of activity in mosquito studies, following the discovery 

 of their disease-carrying habits, considerable confusion was caused 

 by revisions of generic and specific names. Fortunately, these names 

 have now become much more stabilized as a result of continued 

 studies in various parts of the world. In the following account of 

 the species the principal synonyms that have appeared in the United 

 States literature are shown in parentheses under the valid name, and 

 in a few cases the common name is also given. 



Genus ANOPHELES Meigen 



(Syn., Nyssorhynchus Blanch.) 



The mosquitoes of this genus breed in a wide variety of aquatic 

 environments, although their production on a large scale is chiefly 

 in permanent bodies of water containing aquatic vegetation or sur- 

 face debris. Descriptions of anopheline breeding places of various 

 types, while not specifically referred to herein, are numerous in the 

 literature cited in this publication. Some of the references dealing 



3 In scientific terminology two names, the generic and the specific, are employed for 

 each kind of organism. A genus is sometimes divided into subgenera and, when given, 

 the subgeneric name is inserted in parentheses between the generic and specific names. 

 The species may also be divided into subspecies or varieties. The name, spelled out 

 or abbreviated, of the person who first described the species is often added after the 

 specific name. If the species is changed to another genus, the name of the author is 

 enclosed in parentheses. The designation of a species may therefore appear as Aedes 

 aegypti or Aedes (Stegomyia) aegypti (L.), etc. 



