BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 45 
SUMMARY OF FIELD OPERATION'S 
Large-scale work programs for the control of white pine blister rusl were 
carried on successfully during the year in cooperation with 31 States and with 
Federal agencies responsible for the administration of public land-. The work 
was continued in July 1935 with the balances of funds allotted by the Public 
Works Administration, supplemented by labor from the Civilian Conservation 
Corps; the latter was used throughout the season in white pine area- located 
within working distances of Civilian Conservation Corps camps. The last of 
July additional emergency funds were made available to the Bureau for con- 
tinuing the control work in 28 States under the Emergency Relief Appropriation 
Act of 1935, and these amounts were supplemented by allotments and contributed 
services from other Federal agencies and from State and local governments and 
private owners. 
In 1935 the white pines on 2.9S2.401 acres of control area were protected by 
the eradication of 140,500,670 Ribes, with an expenditure of 884,077 man-days 
of labor. In this work the Civilian Conservation Corps supplied 483,571 man- 
days of labor and destroyed 69.983,328 Ribes on 922.974 acres of land. The 
remainder of the work was performed with regular, State, and local cooperative 
funds and allotments under emergency appropriation acts. Approximate y 
20,000 men were employed on this work, about half of whom were security-wage 
workers and the others C. C. C. enrollees assigned to this project from 2^ » 
camps. In addition, protective zones totaling 44,216 acres were eradicated of 
Ribes around 59 white pine producing nurseries to assure the production of 
disease-free planting stock : 51.903 cultivated black currants, the chief agent in 
the long-distance spread of the rust, were destroyed; white pine areas aggre- 
gating 2,364,185 acres were located and mapped to determine the extent and 
value of the white pine growing thereon and the best and most economical 
Ribes eradication methods to be employed ; 39,407 planted and ornamental white 
pines of high value were treated for the elimination of infection by removing 
65,823 blister rust cankers; and 67.666 diseased trees that could not be saved 
were destroyed in plantations and parks. 
The land area in this country on which currants and gooseberries (collectively 
called Ribes), the alternate host plants of the rust, should be suppressed to 
protect the white pines aggregates some 25.969,833 acres. This control area sup- 
ports over 15.501.595 acres of commercially valuable white pine timber and the 
younger growth that will form the next crop. The stumpage value of the tim- 
ber is estimated to be about $400,000,000 and much of it is in public ownership. 
Under the emergency relief and previous work programs approximately three- 
fifths of the control area has been protected by the initial eradication of Ribes.' 
In addition, 14 percent of the protected acreage has been worked twice and 
about 1 percent three times to keep the Ribes suppressed and the disease under 
control. In accomplishing these results over 553,558,883 Ribes have been 
destroyed during the working of 17.387,243 acres in the control areas. The 
emergency relief work programs of the last 3 years have made possible a rapid 
increase in the progress of this work. Under these programs over 393,784,902 
Ribes have been removed from 6,741.885 acres with 2,168,667 man-days of labor. 
In the last 3 years considerably more than half as much pine acreage has been 
brought under control as was accomplished in the previous 15-year period. 
Very little new infection is occurring on white pines in those areas that have 
been brought under control by the eradication of Ribes, but in similar unpro- 
tected areas the rust is accumulating each year and causing serious losses in 
white pine stands, particularly among the younger age classes. 
ENFORCEMENT OF THE WHITE PINE BLISTER RUST QUARANTINE 
The demand for five-leaved pines during the past 2 years has increased to a 
marked extent owing apparently to recognition by the public of the value of 
such trees in reclaiming idle land- that are aot well adapted for the usual 
farm crops, in planting watershed areas, and in preventing soil erosion. 
Under the regulations of the white pine blister rust quarantine, the interstate 
movement of five-leaved pines from the infected States to any state other than 
to New York and New England is authorized only under Federal pine-shipping 
permit. Such permits are issued only for five-leaved pines which have been 
grown from seed tinder prescribed sanitation conditions. In order to comply 
with these requirements it is usually necessary to have a crew cover the 1,500- 
foot zone around the five-leaved pine block one or more times each spring after 
