BUREAU OF ENTOMOLOGY AND PLAXT QUARANTINE 
43 
to 1,391,884 acres, or approximately one-hit If of the area. Of this acreage, 
1,328,787 acres represents initial working, 59,528 acres have been given a second 
eradication, and a third working has been necessary on 3. .".74 acres. 
Table 15. — Rites-eradication operations for the calendar year 19S5 
Region 
Total pine 
area of 
sufficient 
value to 
justify pro- 
tection i 
Control 
area (in- 
cluding 
border 
zones) ' 
Area cov- 
ered in 
1935 
Effective 
labor in 
1935 
Ribes de- 
st roved in 
1935 
Northeastern States 
Acres 
7,667,127 
1. 275, 081 
1, 254, 394 
2, 710, 129 
2, 200, 316 
394, 548 
Acres 
12, 572, 879 
3, 831, 204 
4, 260, 757 
2, 710, 129 
2. 200, 316 
394, 548 
Acres 
1, 125, 198 
999, 116 
483, 877 
272, 718 
93,109 
8,383 
Man-days 
381, 554 
34, 327 
183,917 
236, 854 
45, 216 
2,209 
Number 
28, 828, 809 
Southern Appalachian States... 
3, 690, 622 
39, 219, 729 
Western white pine (Idaho, Montana, Wash- 
53, 514, 386 
15, 013, 191 
Rocky Mountain States (Colorado and Wy- 
oming) 
233, 933 
Total 
15, 501, 595 
25, 969, 833 
2, 982, 401 
884,077 
140, 500, 670 
1 Pine and control-area acreages materially revised from figures given in previous reports, especially as to 
pine acreages in the Southern Appalachian and Lake States. The revised estimates are based on forest 
surveys carried out in 1935 and 1936. 
A strip survey was conducted late in the fall of 1935 in order to procure a 
sample of average pine-infection conditions in the western white pine region. 
Of 27,144 pines examined. 417, or 1.54 percent, were infected. The heaviest 
infection was found in and near the St. Joe National Forest, where 345 of the 
8,350 pines examined, or 4.13 percent, were infected. The percentage of infection 
found on the other pine-growing national-forest areas of the region was as fol- 
lows : Clearwater, 1.S5 ; Coeur d'Alene, 0.65; Kootenai and Cabinet, 0.07. The 
survey strips were so located as to represent average conditions as far as pos- 
sible, without regard to whether they ran through protected or unprotected ter- 
ritory. The figures given show the percentage of trees with visible blister rust 
cankers and therefore do not include trees infected within the last year or 
two, since the cankers on them are still in the incubation period of the rust. 
Work was continued on the improvement of chemical methods of destroying 
Ribes. Tests of the decapitation method on the Sierra gooseberry (A', roezli), 
consisting of the removal of the top of the bush by cutting through the crown 
and the application of the chemical to the cut surface, showed that Diesel oil 
is the cheapest and most effective chemical for this species. Borax is not suf- 
ficiently toxic to it for regular eradication work, in marked contrast to its 
effectiveness on R. visoosissimwm. Decapitation tests in Idaho showed that 
decapitation and chemical treatment of the sticky currant (R. uiscosissimum) , 
the prickly currant (R. lacustre), and the rock gooseberry (A\ irriguum), con- 
stitute an effective eradication practice. A study of the squaw currant I B. 
cereum) plots in Oregon showed that only those methods which involve the 
sprinkling of Diesel oil on intact and on decapitated crowns warrant considera- 
tion as eradication methods. One hundred percent destruction of large squaw 
currant clumps can lie accomplished by sprinkling the decapitated crowns with 
an average dose of one-third of a gallon of Diesel oil per clump. 
NEW INFECTION FOUND IN LAKE STATES 
Indiana and Illinois were added in 1935 to the Lisl of Infected States, the rust 
having been found on Ribes in Lagrange and La Porte ('..unties. Ind.. and in 
Jo Daviess County, 111. In addition, infection on Ribes was reported for the 
first time in Trumbull, Portage, and Summit Counties, Ohio; Iron. Outagamie, 
and Waushara Counties. Wis.: and Allegan County, Mich. Pine infection was 
found for the first time in Wayne County. Ohio; Rusk County, Wis.; and Delta. 
Benzie, Newaygo, and Montcalm Counties. Mich. A Large Dumber of young 
cankers and new infection centers were found in the Lake Stales, indicating 
that the amount of rust was increasing at a rapid rate on unprotected pine. In 
Wisconsin, Minnesota, and Michigan pine infection was found quite generally 
