INSECTICIDES AND REPELLENTS 69 



Ten-percent DDT dust has been used successfully for destroying- 

 rat fleas in citywide campaigns conducted by Federal and State 

 health agencies for the control of murine, or endemic, typhus. The 

 dust is blown by hand or power duster into rat burrows, runways, 

 and all accessible harborages, where it evidently is picked up by the 

 rats in sufficient quantities to destroy the fleas on their bodies and in 

 their nests. A foot pump such as is used for applying cyanide is one 

 type of duster recommended for treating the burrows and a hand 

 dust-sifter for treating the runways. 



Household pyrethrum sprays with added synergists applied thor- 

 oughly to floors and lightly misted on furniture and other places where 

 fleas may occur will also control infestations. Treatments may have 

 to be repeated at intervals of several days. 



In laboratory tests at Orlando heptachlor, dieldrin, aldrin, and 

 lindane dusts were all more toxic than DDT to fleas. In Korea the 

 human flea was prevalent in native houses with dirt floors. Lindane 

 and dieldrin emulsions sprayed on the floors once a week were effec- 

 tive, particularly when rat baits containing warfarin were exposed 

 concurrently. Chlordane was less effective than lindane or dieldrin 

 but more effective than DDT. On grounds or in buildings not occupied 

 by people, lindane, chlordane, or dieldrin may be used in sprays or 

 dusts. A thorough treatment of the grounds with a large volume of 

 spray may be necessary because of vegetation and debris. Two 

 gallons of a spray containing 1 percent of DDT, 0.5 percent of chlor- 

 dane, or 0.125 percent of lindane or dieldrin is suggested for each 

 1 .000 square feet. 



ANTS 



Chlordane is especially toxic to ants. A 2-percent solution in 

 kerosene is recommended for their control in buildings. It may be 

 applied with either a paintbrush or sprayer to table legs, window 

 sills, pantry shelves, and around sinks, drainboards, and water or 

 drain pipes or other places where ants are seen crawling. Emulsions 

 or wettable-powder sprays containing about 0.5 percent of chlordane 

 are useful in treating ant mounds in lawns and fields. 



The imported fire ant has become a serious pest in Alabama and 

 Mississippi and seems to be spreading rapidly into adjoining States. 

 A spray containing 0.37 percent of chlordane has been recommended 

 for its control. About 3 gallons should be applied to an average-sized 

 mound, or sufficient to saturate it and an area about 3 feet wide 

 around it. 



SAND FLIES 



In the United States the name "sand fly" is applied to species of 

 the genus Culicoides (family Ceratopogonidae) found along the 

 Atlantic and gulf coasts. In other parts of the world the name is 

 applied to species of the genus Phlebotomus (family Psychodidae, 

 or moth flies). Except for their small size, the two genera are entirely 

 dissimilar in habits and distribution, and the confusion of names is 

 unfortunate. It is suggested that when used for Culicoides the name 

 be qualified as salt-marsh or culicoid sand flies. 



The Culicoides species, so far as known, all breed in moist soil, 

 and most of them are found in fresh-water locations, principally in 

 tree holes and along the banks of ponds and spring-fed streams. In 



