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CONTROL MEASURES FOR DUTCH ELM DISEASE 
By WILLIAM E. SOUTHERN 
ONE OF THE MOST controversial biological issues of our time is a method 
for saving American Elms from devastation by Dutch elm disease without 
damaging wildlife and ecological interrelationships. Since the 1930’s Dutch 
elm disease has spread from the East Coast to the Mississippi River and 
beyond. Much effort and money has gone into attempts at control. Recent 
research indicates the possibility of controlling the disease without the de- 
struction of wildlife that has occurred in some spray programs. However, 
while research continues, many individuals and agencies are using inade- 
quate methods in hopes of retarding the disease. Arguments justifying the 
use of toxic sprays, such as D.D.T., contend that our stately elms mean 
more in terms of property values than the few robins that are killed. This 
statement is open to argument, but the issue at hand is much larger. It is 
not simply the loss of a few birds due to insecticide application, but the dis- 
ruption of our entire biological community that should awaken us to the 
need for caution. 
It is my conviction that a complete sanitation program, removal of dead 
elms and dead wood from living elms, wherein the bark beetles which spread 
the disease breed, would probably be as successful as any program involving 
D.D.T. applications. In this connection I will describe the control program 
recently enacted in DeKalb, Illinois, as well as some control measures used 
by other communities. I will also discuss some biological] facts indicating 
the need for additional research while a particular insecticide is used. 
It is not my intention to cover the subject completely. I hope that my 
comments will stimulate evaluation of the control program used in your 
community. I will, upon request, provide readers with a bibliography per- 
taining to Dutch elm disease, toxic effects of insecticides, etc. 
In the fall of 1960, a committee of DeKalb citizens became concerned 
about a proposed spray program for Dutch elm disease in the community. 
At that time several hundred elms were dead in the city and no preventa- 
tive measures had been attempted. I was asked to become a committee mem- 
ber. Our interest, discussions and research resulted in the City Council de- 
ciding not to approve a spray program. Instead street crews spent the 
winter months removing dead elms from the parkways. An ordinance was 
enacted whereby citizens were required to remove dead elms from private 
property. Several organizations offered to replant city parkways with trees 
of various species recommended by our committee and purchased by the 
city. Progress was made in the sanitation program, but much has yet to be 
accomplished. For such a program to be successful, it is necessary to ex- 
tend coverage into nearby rural areas and neighboring communities. 
As a result of my research and continued interest in the problem, I have 
attempted to evaluate the programs currently attempted to prevent the 
spread of Dutch elm disease. Some programs have been directed toward the 
causative fungus, Ceratocystis ulmi, and others toward the insects apparent- 
ly responsible for spreading the fungus, the elm bark beetles, Hylwrogopinus 
rufipes and Scolytus multistriatus. Most of the programs involving insecti- 
cides leave much to be desired. Methods used by many communities for con- 
trol of bark beetles are but half-hearted attempts to stop the spread of 
Dutch elm disease and whole-hearted attempts to show the public that some- 
thing is. being done. Often the decision to spray or not to spray is left to a 
