40 
EASTERN SHADE TREE CONFERENCE 
breeding in dying or weakened trees as well as having the effect of con¬ 
centrating populations of leaf-feeding insects on the surviving trees 
another season. 
Structural weakening of many trees is due, directly or indirectly, to 
insect attack. It was notable that trees in the open country escaped 
storm damage to a perceptibly greater extent than city or town trees. 
It is believed that a part of this exemption is due to better growing 
conditions and relative freedom from insect attack in the case of the 
trees in the open country. In general, the well-cared for tree, free from 
structural defects, or properly braced and cabled, with a deep strong 
root system, was, other things being equal, the tree that fared best during 
the storm. The hurricane was a great detector and selector of weakened 
trees, culling out a high proportion of these in the areas where the 
storm was most violent. 
What are some of the factors that have operated over a period of 
years to bring trees to a condition so devitalized that they easily suc¬ 
cumbed to the hurricane? Damage by insects has been a major con¬ 
tributing influence. Defoliation or partial defoliation of shade trees is 
well known as a factor contributing to weakening them. That the full 
effect of such weakening may not be consumated for many years was 
demonstrated by conditions attending our last hurricane. 
Shade trees in cities and villages in many parts of the hurricane area 
have during the past 40 years suffered from such leaf feeding insects as 
the Gypsy Moth, probably the most destructive general tree feeder in 
New England where it has caused millions of dollars worth of damage in 
the past and where during the past few years it has been increasing and 
extending its range; the Canker Worms, both spring and fall species, 
which have defoliated thousands of elms, oaks, hickories and other trees 
in southern New England and southeastern New York state during 
the past decade; the Elm Leaf Beetle, the outstanding leaf -feeding 
insect attacking elms, an introduced pest which has been present in this 
country for more than seventy-five years, and which, where spray 
measures are not practiced, still defoliates many trees; and others. 
The Elm Leaf Beetle became destructive in the Connecticut River 
Valley and eastern Massachusetts in the early 1900’s. Spraying to pro¬ 
tect shade trees from these pests was little practiced during the early 
part of this period and many city and village trees that lay in the storm 
area have suffered greatly from elm leaf beetle attack over much of the 
past 40 years. 
