BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 39 
DUTCH ELM DISEASE ERADICATION 
GENERAL STATUS 
Activities during the year disclosed a 49-percent reduction in the 
number of trees found to be infected with Oeratostomella ulmi, the 
fungus causing the Dutch elm disease, as compared with the preceding 
year. Intensive scouting in sections where heavy concentrations of 
the disease or dense infestations of the bark beetle carriers of the 
fungus occurred in the summer of 1938 showed uniform reductions 
in confirmations in these areas. With a few comparatively unim- 
portant exceptions, this same condition was found throughout the 
main region in which the disease is discontinuously scattered. 
There was a still further reduction this year in the number of cases 
discovered at outlying points. Of 16 confirmation- reported from 
States outside the major disease area, 9 were in the Indianapolis, Ind., 
area, 6 in xYthens County, Ohio, and 1 in Cumberland, Md. 
Results of the eradication work in Indianapolis were encouraging, 
evidencing the benefits of the extensive elm-sanitation campaign per- 
formed in that section. The only extension of area there was in a 
section about IV2 miles to the northwest. There was no recurrence 
of the disease in the original Brightwood area. Only one diseased 
tree was found in each of the three previously located heavily infected 
centers in Indianapolis. One of the diseased trees in the Athens area 
was found at a new infection center at Hockingport, at some dis- 
tance from the other infections in the county. The Cumberland 
tree was the first confirmation in Maryland since 1936. No reappear- 
ance of the disease was observed in the other isolated cities where 
small numbers of infected trees had been destroyed in earlier years. 
Regulations supplemental to quarantine No. 71 continued in force. 
The regulations were amended, effective September 11, 1939, to include 
in the area infected by the Dutch elm disease additional townships in 
Connecticut, New Jersey, and New York. Federal quarantine action 
was withheld in the case of the Pennsylvania infected zone, since the 
State placed an embargo on the movement of elm material therefrom. 
This action continued the Federal embargo on the movement of 
sources of infection from heavily infected sections of New Jersey into 
Pennsylvania, where infection is limited. 
SYSTEMATIC SCOUTING 
Foremost among the newly discovered main-area infections this 
year was the disease center found in 6 towns just east of Binghamton, 
Broome County, N. Y. This is approximately TO miles from the 
main disease zone and is being handled as a separate area. Other- 
wise in New York the infection zone was rounded out by the finding 
of diseased trees in many of the Dutchess, Orange, and Ulster County 
towns intervening between detached infections discovered in previous 
yeaiu First-record cases were found in a few towns in Litchfield 
and New Haven Counties, Conn., east and north of previously known 
infected territory in that State. As scouting progressed in the re- 
mainder of Bucks County, Pa., further incursions of the disease were 
found in most of the townships and in a few adjoining townships in 
Lehigh and Northampton Counties. A few diseased trees were 
found in several townships in Monroe County, Pa., bordering the 
