BUREAU OF ENTOMOLOGY AND PLAN T QUARANTINE 41 
Summer scouting in 1939 was the most extensive ever undertaken. 
It included a complete first survey and a 60-percent second coverage 
of the major disease area, approximately the extent to which the 
known infected zone was covered in 1938. One complete coverage 
and an approximate 70-percent completion of the second survey was 
accomplished in the protective zone circumscribing the major disease 
area. These two areas, including roughly the territory within a 70- 
mile radius of Xew York City, comprise the work area to which 
systematic scouting was confined in previous years. 
^ Beyond the confines of the work area as defined in previous years, 
scouting during 1939 was expanded to include advance survey work 
in the sector between the 70- and 100-mile radius lines from New 
York City. This area was given one complete go-over, with 67-per- 
cent completion of a second survey. The results were negative. 
Still more remote from the main area of infection was an extension 
survey in the territory lying between the 100- and 150-mile circum- 
ferences. This was of an exploratory nature to determine what could 
be found beyond the advance survey area by very light scouting. It 
resulted in the finding of the diseased trees in the Binghamton, N. Y., 
area. 
Autogiro scouting of approximately 4,500 miles of railroad rights- 
of-way was repeated during the summer, again with negative results. 
Southern railroads from Norfolk to New Orleans were omitted from 
this year's program, since repeated surveys of these lines failed to 
link any southern States with the Dutch elm disease. Ground crews 
associated with the flying units found infestations of ScoJytus midti- 
striatm (Marsh.) in the western part of Pennsylvania, and confirmed 
reports of the presence of this species at Columbus, Ohio, and Roches- 
ter. N. Y. 
Scouting in the isolated infected regions was both timely and thor- 
ough. Previous years' elm-sanitation activities in these areas facili- 
tated the surveys in the environs surrounding Indianapolis, Ind. : 
Athens, Ohio; Cumberland, Md. ; and adjoining West Virginia and 
the Potomac Valley. 
During the year 72.781 samples of elm wood suspected of contain- 
ing the elm-disease fungus were submitted to the laboratory for cul- 
turing and determination. From 9,189 of these samples Ceratosto- 
mella uhni was cultured. Segregated as to location, 368 confirmations 
were in Connecticut, 7,501 in New Jersey, 1,088 in New York, 216 in 
Pennsylvania, and 16 at the several isolated infections. 
Wilting and discoloration characteristic of Dutch elm disease infec- 
tion were first found in the spring of 1940 on May 18, in Connecticut. 
General wilting of elm foliage was observed early in June. 
Since discovery of this disease in the United States in 1930, a grand 
total of 57,400 elms have been confirmed as infected. Of this total. 
1.339 were in Connecticut, 45,152 in New Jersey, 10,470 in New York, 
262 in Pennsylvania, and 177 in the localized infection centers in States 
remote from the major infected regions. The accumulative total of 
177 cases at the isolated infections comprises the following: 113 in 
Indianapolis, Ind.; 2 in Baltimore, 3 in Brunswick, and 2 in Cumber- 
land, Md.; 12 in Athens, 1 in Cincinnati, and 33 in Cleveland. Ohio: 
5 in Norfolk-Portsmouth, Va. ; and 6 in Wiley Ford, W. Va. 
