64 
EASTERN SHADE TREE CONFERENCE 
adjacent areas were responsible for the increase in Graphium of this 
year. Upon receiving this field information from the various county 
supervisors we were incidentally informed that the one-mile wide band 
which was used as a basis for the collection of the data should be divided 
into an inner one-half mile band and an outer one-half mile band. In 
so doing we ascertained that approximately 80 per cent of the Graphium 
trees occurring within the one-mile wide band around clean-cut silvicided 
areas occurred within the inner one-half mile band. This information 
indicates that the beetles emerging from the silvicided plots did not, 
generally speaking, fly very far beyond the limits of the first available 
elm trees. 
As previously stated this silviciding work was, almost in its entirety, 
confined to swampy areas and mountainous terrain, therefore, the trees 
involved in the Graphium confirmations around these areas were in rural 
woodland areas. Very few ornamental trees were involved. The aver¬ 
age D. B. H. of the Graphium trees around these silvicided areas was six 
inches. 
Having thus analyzed the silviciding data and arrived at the con¬ 
clusion that this operation was in part, if not in entirety, responsible for 
the increase in Graphium for the year 1938, the question still remains 
how much longer these trees will provide facilities for bark beetle 
multiplication. A careful examination of representative areas of 
silvicided trees indicates that not more than 4 per cent of the 600,000 
silvicided trees will liberate beetles next spring. No attempt has been 
made to predict the inroad which will be made by woodpeckers on the 
remaining bark beetle population this winter. It is known that the 
population of woodpeckers in the Dutch elm disease area in New Jersey 
has been significantly increased. We can, therefore, assume that the 
silvicided trees in the State of New Jersey will become practically func¬ 
tionless so far as the dissemination of the Dutch elm disease is concerned. 
In consideration of the Dutch elm disease eradication work in New 
Jersey there is one more factor of which I speak reluctantly and yet 
which cannot be ignored if a complete picture is to be established. I am 
making reference to the non-acceptability of W. P. A. labor for scouting 
and supervision work. At the beginning of each calendar year a work 
program for Dutch elm disease eradication work in the State of New 
Jersey is constructed. This program calls for a certain number of 
supervisors, a certain number of scouts and a certain number of laborers. 
At no time has this program requisition been met. Ofttimes the num- 
