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A water suspension of DDT (1 pound per 100 gallons) is preferred 
for the control of flies in dairy barns because of the danger of the 
operator becoming thoroughly wet with a kerosene solution and hence 
poisoned when it is necessary to spray overhead .--Michelbacher ( 256 ) • 
A 10 percent DDT-pyrophyllite dust was applied in a dairy barn 
about 3 p.m. on July 25 by means of a hand duster; this was directly 
after the cattle had been brought in from out-of-doors. Immediately 
prior to application the floors were swept clean and most of the 
windows dosed. Within 15 to 20 minutes the flies were observed 
dropping to the floor, and by 4 p.m., which was milking time, no fly 
spray was needed before the cows could be milked. Approximately 3 to 
4 flies per square foot of floor surface were killed the first day 
after the dusting, but the number rapidly diminished thereafter. On 
the third day the herdsman found it necessary to resume the applica- 
tion of a fly spray. A spray made by adding a 25 percent DOT self- 
emulsifying conoentrate to water (1:160) plus 1.4 pounds of blue vitriol 
per 100 gallons greatly reduced the number of flies in a hog barn.— 
Munro j3t _al. (271 ) • 
A small unscreened compartment containing a bull was sprayed with 
3 percent IDT in kerosene. One hour after spraying all flies were 
dead or affected and for 9 days thereafter fly annoyance was at a 
minimum. A small unscreened stable was sprayed several times with 1.5 
to 3 percent DDT in kerosene. A manure pile adjacent to the stable 
served as a constant source of reinf estation. Flies were eliminated 
from the stable for 1 day after treatment. They were present there- 
after in about the same numbers as before spraying. Three percent DDT 
in kerosene gave control of flies in chicken coops for about 3 weeks. 
In other tests 3 percent IDT in kerosene sprayed on the outside of the 
kitchen at the Merchant Marine rest home failed to give relief. Spray- 
ing the inside of a dairy barn feed house where flies congregated with 
3 percent DDT in kerosene gave unsatisfactory control.— N. J. Agr. 
Sxpt • Sta . (275 ) . 
Two methods were used to control flies in barns in Minnesota. In 
one test all the screens were painted with 5 percent of DDT in kerosene. 
In the other tests water suspensions of Neocid A-5 or Neooid A-20 were 
sprayed on the walls and ceiling. Painting the screens killed large 
numbers of houseflies and stableflies, but the amount of surface treat- 
ed was too small to give satisfactory control. It was estimated that 
the population was reduced by 30-40 percent after the screens were 
treated. A water suspension of 2 percent of Neooid A-5 gave fair con- 
trol for about 1 month when applied to walls and ceiling as a coarse 
spray. Both a 1-percent and a 2-percent suspension of Neocid A-20 gave 
much better control, with the latter giving good results for 6-8 weeks. 
One barn with about 5,000 square feet of sprayed surface was kept free 
