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"Contrary to reports from some of the earlier experiments however, 
rflTT has no magic power of spreading itself over water surfaces. In 
dispersing the small amount of material required, one must make sure 
that it is introduced over the entire surface, particularly if rafts 
and booms of floatage will cut its access to the sheltered areas where 
breeding may be intense. In dispersing the 5-percent kerosene mixture, 
one may well apply the material from the windward side and allow it to 
drift over the breeding area* In order to increase the coverage and 
to cut do-wn the care which is necessary in applying minute amounts with 
kerosene as a carrier, considerable work has been done with emulsions. 
By using a quick-breaking emulsion, such as is made with phthalic glyceryl 
alkyd resin, one can apply the material on the acre basis, figuring at 
the rate of about l/lO pound of DDT per acre. If, however, a tight 
emulsion is produced, as with polyethylene emulsifier, the dosage should 
be figured roughly on a voluroetrio basis so that the DDT will not exceed 
1 part in 10 million. Any greater concentration will certainly be detri- 
mental to fish. The addition of DDT to irrigation water at its source 
has proved particularly disappointing." 
A residual spray applied at the rate of 100 to 200 milligrams per 
square foot will effectively kill all adult mosquitoes that come to 
rest on the treated walls for a period of at least 3 months and possibly 
longer.— Freeborn (160) • 
Same as Aedes sollicitans .— Ginsburg ( 178 ) * 
DDT is more toxic to mosquito larvae than any agent heretofore 
known. Consequently, it can be used in small amounts with resultant 
saving in time and effort. Sprayed on interior surfaces IDT remains as 
a residue which will kill insects lighting on the treated areas for 
several months. Thus, by spraying the habitations of native carriers, 
a long-lasting means is provided to destroy infected mosquitoes which 
might convey malarial parasites to troops. DDT, just recently available 
in quantity for mosquito control, is a revolutionary new weapon in the 
fight against malaria.— Simmons (519 ) • 
Anopheles triannulatus (N. and P.) 
Same as for Anopheles albimanus .— Gorgas Memorial Laboratory (182 ) • 
Anopheles spp. 
For the control of adults with residual sprays a dosage of 100 
mg. of DDT per square foot should be aimed at. Another promising use 
of the film effect is the impregnation of wide-meshed bed nets, which 
would probably make them effective barriers against small species of 
Anopheles, and also against such little pests as Fhlebotomus. 
