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DDT emulsions, or by impregnating clothing or sacking soreens*- Buxton 
(100), 
Musoa domeatloa L*, the housefly 
A 2-peroent solution of DDT in deodorised kerosene sprayed on the 
walls and ceiling of a poultry killing room gave 100-percent mortality 
of flies in the room up to a month after treatment. Over a 6-week 
period only 8 percent as many flies were observed within a poultry lay- 
ing house, the walls and ceiling of which had been sprayed with a 3- 
percent solution of DDT in deodorised kerosene, as were seen in an un- 
sprayed house.— Wolf enbarger _et al . (379 ) • 
See also under Themira putris *—-ffolf enbarger et al * (379 ) • 
See Anopheles spp*— Farr (149) ; Anon* (19) • 
In one test a 0*01-percent solution of Gammexane killed 73 percent 
of a known number of flies, whereas a 0*02-percent DDT solution killed 
only 51 percent*-- Anon* (52)* 
DDT may be sprayed over wide areas from the air* In Sweden farm 
and grain areas have been treated, this way throughout the year at inter- 
vals of several months and dairy farms have been practically fly-free 
during the entire summer. Increase in milk production was noted. In 
the future there may be derived an effective insecticide from the com- 
bination of pyrethrum (or derris) and DDT, in which the pyrethrum will 
have the rapid and the DDT the lethal action*— Ahlb erg and Mathlein 
(69). 
Unpublished figures by Parkin and Green of the Department of 
Scientific and Industrial Research [Great Britain] show that 0.05 per- 
cent of DDT plus 0.02 percent of pyrethrins is barely satisfactory 
against flies. A mixture containing 0.10 percent of DDT and 0.03 
percent of pyrethrins, applied with hand sprayers at the rate of 26 
co. per 1,000 cubio feet in rooms and army huts at about 24 C. gave 
a high knock-down and killed all the flies. These workers have also 
shown that mixtures of DDT and pyrethrum in kerosene can be stored 
under suitable conditions for at least 17 months at 27.5°C. without 
marked deterioration. The present British official recommendation for 
a general spray for killing adult flies and mosquitoes is 0.07 percent 
pyrethrins (or more if available) j or 0.05 percent pyrethrins + 0.3 
percent DDT; or 0.03 percent pyrethrins +0.5 percent DDT. The per- 
centage of DDT refers to the pure para-para-prime substance. The 
dosage is 10 cc. per 1,000 cubic feet (l fluid ounce per 3,000 cubic 
feet), subject to considerable latitude, if used in rather open huts. 
—Buxton (100) • 
