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Not affected by a deposit of DDT on filter paper during 6 days. — 
Vargas and Colorado Iris (360 ) • 
Periplaneta americana (L.), the American cockroach 
■ ■■ ir ■ in ■ !■■■!- - <m ■ i ■ ■ ir - - -r - 
This roach succumbed to Gesarol A-3 dust when its runways and trails 
were dusted.— Parker (287 ) • 
Unidentified species 
_ i i - i ■ i i * - - - - 
All the common household roaches, except the German roaches, are 
easily controlled. Either a 10-percent DDT dust used along the areas 
generally traversed by roaches, or a kerosene spray containing 5 percent 
of DDT heavily applied, is the most effective means of control* A 25- 
percent dust or repeated applications of the 5-percent kerosene spray 
will eventually make some inroads on the German roach. For practical 
purposes, however, there is little to be gained by substituting DDT pre- 
parations for the orthodox treatment with sodium fluoride, particular- 
ly for the German roach.— Freeborn ( 160 ) • 
A 10-percent DDT dust controlled roaches •--Haseman (203 ) . 
Cockroaches appear to be somewhat resistant to DDT, at least in the 
form of 5 to 10 percent dust. It seems that they are also rather re- 
sistant to the films that are left on sprayed surfaces. Several reports 
indioate a great reduction, but not complete extermination, of cockroaches 
of several species. Busvine, for instance, sprayed a bakery infested 
with Blatta , putting down a film estimated at 100 to 150 mg. per square 
foot. Those insects which were hit during the spraying died, but there 
were many live ones running on the film a week later.— Buxton ( 100) • 
Gryllidae 
Acheta ( = Gryllus ) assimilis (F*), the field cricket 
Acheta domesticus L., the house cricket 
Apparently killed by DDT residual sprays.— Ross (306). 
The field cricket was very abundant on many of the plots and was 
more susceptible to DDT than grasshoppers. In one instance, where there 
was a light drift of 15-percent DDT dust from a treated plot to an ad- 
joining field, dead crickets were found 150 feet beyond the plot. — 
Parker (286) . 
