4 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 194 4 
Schley and Stuart varieties t lie percentage of nuts infested was reduced 
about one-half, and the treatment more than doubled the yield of nuts. 
CHERRY FRUITFLIES CONFORM TO LIFE ZONES 
The cherry fruitflies, chiefly Rhagoletis cingulata (Loew) and to a 
lesser extent R. fai/sta (O. S.), have been found on the west coast in 
the Transition and Canadian Life Zones from the Sequoia National 
Forest north, wherever the preferred wild host, Prunus eiyiarginata 
(Dougl.) Walpers, occurs. South of that point this host has not 
fruited for several years. In California these life zones occur at eleva- 
tions mostly above 5,000 feet, where cultivated cherries are not grown. 
In Oregon cultivated cherries are grown in the Transition Zone, and 
in parts of that State they are extensively infested. This study was 
made by the Oregon Experiment Station in cooperation with the 
Bureau and the California Department of Agriculture. 
GASTIGHT TENTS GIVE IMPROVED CONTROL OF CALIFORNIA RED SCALE 
In studies of the California red scale carried on at Whittier, Calif., 
considerable work was done in the field with tent fabrics differing in 
gas-retention properties. Fabrics treated with certain plastic products 
were found to retain three to four times as much gas to the end of a 
45-minute exposure period as the standard fumigation tents now in 
use. Correlated with the gas retention is a higher mortality of scales, 
or the possibility of an equal kill with lower initial dosages.' With the 
blowers and gastight tents it has been possible to duplicate concentra- 
tions in successive exposures on different trees, and from night to 
night. By using scales of a known age and strain, it has also been 
possible to duplicate very closely the mortality obtained. 
MILKY DISEASE CONTROLS JAPANESE BEETLE GRUBS 
The milky disease of the Japanese beetle has continued to cause 
conspicuous reductions in infestation of the grubs wherever it has 
become well established in the soil. In the Mall section of Washing- 
ton, D. C, for instance, where populations as high as 50 grubs per 
square foot of turf were recorded in 1941, and which received an 
intensive milky disease treatment, practically no grubs or beetles 
were in evidence during the spring and summer of 15M4. The coloni- 
zation of the organisms causing this disease is being continued. 
At the request of the Office of Chief of Engineers. War Department, 
surveys of Japanese beetle grub infestation in maintained grass or 
essential turf areas were undertaken at military installations in the 
First, Second, and Third Service Commands during the dormant 
season of li>lo-14. A program of milky disease 4 treatment was 
started in March 1944 at installations where conditions called for 
treatment. 
DDT EFFECTIVE AGAINST JAPANESE BEETLES 
In field tests against adult Japanese beetles during the summer of 
1948, 1 i pound of DDT per 100 gallons afforded the same protection 
to peaches as a single application of the recommended derris-rosin 
residue emulsion spray, protect ing both fruit and foliage for 2 weeks. 
