BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 
61 
principal host plants inspected and certified comprise 1 dahlias, gladi- 
olus, and chrysanthemums, from Maryland, New York, Ohio, Penn- 
sylvania, and Virginia. 
BARBERRY ERADICATION 
Recent progress in barberry eradication has demonstrated that, (1) 
in approximately 75 percent of the counties comprising the IT States 
engaged in the regional stem rust control program, barberry bushes 
have escaped from cultivation, and an intensive survey of all tim- 
bered areas and other uncultivated lands is necessary to insure com- 
plete eradication; (2) by carefully mapping barberry-infested areas 
when the initial survey is made, it is possible to eliminate from further 
attention large areas where bushes have not become established, or 
in which eradication has been accomplished, thus reducing by approxi- 
mately 50 percent the territory that will require one or more rein- 
spections; (3) single barberry bushes, if allowed to remain scattered 
throughout grain-growing areas, not only are sources of seed and local 
rust-infection centers but may serve as sources of new physiologic 
races of the disease, some of which may be capable of attacking vari- 
eties of small grain that are resistant to the particular races of the 
disease generally prevalent at the present time. 
To protect grain crops from stem rust has been foremost in the 
minds of farmers in the Central and Western States for nearly 40 
years. It was not until 1918, however, that a regional control program 
involving 13 North Central States was undertaken, with the United 
States Department of Agriculture assuming responsibility for gen- 
eral administration and coordination of the work. At that time legis- 
lation was enacted in Colorado, Illinois, Indiana. Iowa, Michigan, 
Minnesota, Montana, Nebraska, North Dakota, Ohio, South Dakota, 
Wisconsin, and Wyoming which prohibited further propagation or 
sale of rust-susceptible species of barberry, and a Federal quarantine 
was established to prevent shipment of other than immune species into 
or between protected States. During the period 1918-82 an extensive 
educational program was conducted to demonstrate to grain growers 
and others the extent to which local barberry bushes were responsible 
for destructive epidemics of stem rust. Statewide surveys were made 
to determine where, and to what extent, barberry bushes had become 
established in grain-growing areas. Funds were not available with 
which to undertake intensive surveys of entire counties, and control 
work was conducted on an area basis in communities where rust losses 
had been particularly severe. While progress toward complete eradi- 
cation was slow during this period, 84,518 properties were cleared of 
18,665,000 barberry bushes, many of which were located in. or imme- 
diately adjacent to, the more extensive grain-growing areas of the 
count ry. 
CONTROL OPERATIONS EXPANDED WITH W. P. A. LABOR 
Since August 1933 an average of 2,200 security-wage employee- 
have been continuously assigned to the stem rust-control program, 
and the protected area has been extended to include Missouri, Penn- 
sylvania, Virginia, and West Virginia. W. P. A. laborers working 
under the direction of Bureau supervisors have completed an inten- 
sive survey of more than 294,600 square miles in IT States and have 
