ENTOMOLOGY AND PLANT QUAltANTINE 
37 
doah. and Warren Counties, \yhere it is probably present but has not been 
reported. No additional A'irginia counties were reported infected in 1936, al- 
though several infected localities were reported for the tirst time in Higidand 
and Rockingham Counties and in the George Washington National Forest. In 
West Virginia the rust was very scarce in 1936, the oniy infection found being 
on two cultivated bushes in one locality in Pendleton County. Four West Vir- 
ginia counties have been reported infected in past years, namely, Pendleton, 
Pocahontas, Randolph, and Tucker. 
In the Lake States, counties in which pine infection was found for the first 
time in 1936 include Keweenaw. Muskegon, Saginaw, St. Clair, and Schoolcraft 
in Michigan ; Buffalo. Door, Eau Claire. Langlade. Outagamie. Price. Sheboygan, 
Vilas, Waushara, and Winnebago in Wisconsin; and Hubbard and Todd in Min- 
nesota. During the same year it was found on Ribes for the tirst time in 
Buffalo. Fond du Lac. Manitowoc. Sauk, Sheboygan, and Winnebago Counties, 
Wis., and in Koochiching County, ^Minn. During the period from January 1 to 
June 30, 1937. further counties reported for the lirst time with infectious on 
pine inciuded Manitowoc, Brown, La Crosse, Monroe, and Sauk in Wisconsin. 
The principal development in the West was the tentative delimiting of the 
infection in California, which, as reported last year, was first discovered on 
June 26. 1936. The surveys including and immediately following this dis- 
covery showed the presence of blister rust in Del Norte County on one sugar 
pine near Monumental and on one Ribes on Rowdy Creek; also in Siskiyou 
County on several sugar pines and Ribes on Indian Creek, and on two Ribes 
on Goff Creek and the Applegate River, respectively. Surveys in Oregon car- 
ried out at the same time showed sugar pines infected in Coos, Curry. Jeffer- 
son, and Lane Counties ; western white pine infected in Curry and Lane Coun- 
ties ; whitebark pines infected in Hood River and Clackamas Counties, and 
Ribes infected at several points in Curry County and on Clear Creek in Jo- 
sephine County. Blister rust occurs generally on Ribes in the northwestern 
quarter of Oregon which was not included in this survey. 
In the "Inland Empire" of Idaho, eastern Washington, and western Montana, 
a pine-disease survey initiated in 1935 was continued in 1936 on a large scale, 
using especially chosen security-wage workers for the purpose. Strips 1 rod 
wide were run on each section line crossing all the important roads through 
the forest areas concerned. The results showed, as a general average, that 4.4 
percent of the trees examined were infected in the St. Joe National Forest, 3.8 
percent in the Clearwater National Forest, 1 percent in the Kaniksu National 
Forest, 0.5 percent in the Kdott-nai National Forest, and 0.2 percent in the 
Mount Spokane area. Special scouting strips were also run through portions 
of these forests which were known to be infected. In the territory scouted on 
these strips it was found that 6.8 percent of the pines examined were infected 
on the St. Joe National Forest. 4.3 percent on the Coeur d'Alene National For- 
est, 6.4 percent in the Kaniksu National Forest, 8.5 percent in the Cabinet Na- 
tional Forest, and 2.8 percent in the Mount Spokane forest area. The number 
of white pines examined on the regular strips was 289.765, while on the scouted 
strips 115.599 pines were checked. The infection reports relate only to trees 
below 20 feet in height. The heaviest infection recorded (81 percent) was in 
that part of one of the areas in the St. Joe National Forest located within 300 
feet of a stream bed on which Ribes petiolare was present. 
IMPROVED METHODS DEVELOPED 
In further studies to increase the efficiency and to reduce the cost of Ribes 
eradication, it was found that the common species of prickly gooseberry {R. 
roezli) in California could be destroyed most effectively by cutting off the top 
of the plant and applying oil to the crown. One oiler with a knapsack spray 
tank accompanies a crew whose members pull the small Ribes and cut off the 
tops of the larger bushes. Diesel oil is then applied by the oiler, using a sprin- 
kling hose attachment to the tank. From 5 to 6 gallons of oil are used per 100 
treated plants. 
Preliminary tests also indicate that dense masses ol Ribes seedlings, which 
often occur in recently burned or disturbed areas, can be killed at reduced cost 
by spraying with oil. 
Promising results of chemical-treatment tests are also being obtained in 
Colorado and Wyoming in a search for methods of Ribes eradicr.tion applicable 
to forest areas where the limber pine {Pinus fte.rilis), the whitebark pine {P. al- 
bicauUs), and the bristlecone pine {P. aristuta) are of imix)rtance for water- 
shed protection and other purposes. 
