THE HALL SCALE ERADICATION PROJECT 7 
OREGON 
BIOWELL eacn ea 
INFESTATION 
NE VAOA 
Figure 4.—Hall scale infestations in the United States, with enlargement of the Chico, Calif., 
areas 
Figure 4 shows the infested areas, all in California. The approximate 
numbers of host plants in these areas were as follows: 
Chico: 
WnitedaStates:PlancaintroductionsGarden tan 4 a le 15,000 
NOHMSO Merny a eo erty eer ee ee, Conn See hot Wag aioe Se aamedar el tau Sie cures ee 3,600 
IREW Ea ais arc Bena aspen ENRON lpn et BU Zee A SB Shee ae eR Oe ee eet 500 
iGavel heat mentee aie wot MMM OO tee ea ete ag eaten nies Rc ne ene ee aU uae ape 15,400 
Rersivalleas aera erik Coos heen ethan Oa Nn ae Ls, 900 
(OF ROR aU MSs ee eT mae aS a ee aoe arch Rt oe ia Naa, a Pace 800 
DAayiIShCatm DUS eee ete eam in crc re mr es wea Dc keene Vomda nine tere, 2,800 
Most of the infestations were near Chico. At Oroville, about 20 miles 
from Chico, eight city blocks were infested. At Davis, approximately 100 
miles south of Chico, in a University of California experimental planting, 
1 As of December 1951, inspection not completed. 
