BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 59 
widespread larval infestations, with sterilizing required for fruit 
shipped from the area late in the season. 
Codling Moth Resumes Important Role 
Despite the fact that most commercial fruit growers obtained good 
control of the codling moth, this pest was generally more abundant 
and caused more injury in 1952 than in any year since 1946, when DDT 
came into general use for its control. Growers are concerned, but 
thus far weather conditions particularly favorable for the develop- 
ment and activity of this insect appear to have been an important, if 
not the most important, contributing factor. Some field experiences 
during 1952 pointed to possible differences in DDT formulations as 
another contributing factor. Thus far, the development of resistance 
of the codling moth to DDT appears to be a threat rather than a 
proved reality. 
In the meantime research continues in an effort to develop supple- 
ments or substitutes for DDT to control this pest. Several promising 
materials are available. 
Two New Mite Species Spread to Midwest Apple Orchards 
A survey of 20 representative apple orchards in the Midwest during 
August and September 1952 disclosed two species of mites present 
that had heretofore been unreported on apples from that area. The 
two species were Tetranychus canadensis (McGregor) and schoenei 
McGregor. Orchards in which these mites were found extend from 
Goshen, Ind., near the Michigan State line, southward through In- 
diana, southern Illinois, and western Kentucky to central Tennessee at 
Jackson; and from Louisiana, Mo., eastward through Illinois to York- 
town in eastern Indiana. 
Introduced Oriental Fruit Moth Parasites Become Established 
Two recently introduced Chinese parasites of the oriental fruit 
moth, Agathis f estiva and Phanerotoma grapholithae, first released 
for colonization in New Jersey and North Carolina in 1951, were re- 
covered from colony sites in New Jersey in 1952. The original stocks 
were furnished by the California Agricultural Experiment Station. 
Colonization was continued in 1952, attention being given to releases 
in south central Pennsylvania and in Connecticut. Thirty-seven sepa- 
rate releases of Agathis and 23 of Phanerotoma were made in the two 
States. Colonies of Phanerotoma were also furnished to the Citrus 
Experiment Station, Riverside, Calif., for colonizing against the 
oriental fruit moth in Orange County, Calif. 
Two Leafhoppers Dominant in Western X Virus Disease 
Transmission 
Two of the four leafhoppers that are demonstrated vectors of west- 
ern X disease and little cherry, Colladonus geminatus and Scaphy- 
topius acutus, are dominant in Washington and northern California 
and appear to be the important economic carriers of these diseases. 
These observations were made in cooperation with the Bureau of Plant 
Industry, Soils, and Agricultural Engineering and the Agricultural 
