bailey: storm damage in Vermont 
25 
In 1936 the infestation was far more general, with widespread damage 
throughout many areas of the southern and western counties. Although 
defoliation was not generally 100 percent, it ran up to 80 or 90 percent 
and hundreds of sugar orchards looked brown and thin. As is the na¬ 
ture of such outbreaks, heavy attacks by the caterpillar were spotty, 
even in the areas of greatest prevalence; and frequently heaviest cater¬ 
pillar abundance seemed to follow along certain ridges, as for instance, 
on a North-South line for many miles, along the first range of hills east 
of the lower reaches of Lake Champlain. There were instances, too, 
where certain sugar places were heavily attacked while there was no 
noticeable defoliation in the orchards surrounding them. There was a 
similar variation among towns in respect to shade tree infestation. 
With diminution in some cases and apparently increase in others, the 
outbreak continued in 1937 and 1938. How many more seasons it will 
take for the natural control agencies to overcome it, no one, of course, 
knows. Though nothing like a complete survey has been made as to 
egg masses on the twigs at present, I know that there are considerable 
numbers of them at some points. 
Since the shade trees are inextricably tied in with the trees of the whole 
countryside, so far as concerns the periodical ups and downs of the forest 
tent caterpillar, it seems best to handle the situation as a whole. There 
is, of course, the decisive difference from the control angle that while 
spraying is a feasible and effective control measure in the case of shade 
trees, it is not so generally practicable in forest or sugar bush areas 
owing to expense and other obstacles. 
Since apparently the range of food plants chiefly favored by this insect 
varies somewhat with different parts of the country, it may be noted 
here that in Vermont the sugar maple is the tree most seriously affected. 
Oak, white ash, poplar and basswood are apparently also prime favor¬ 
ites, but since these varieties seldom grow in solid stands in Vermont 
and are not much used for shade trees, attacks of the caterpillar on them 
are of much less importance than are those on the sugar maple. Elm 
and birch appear to be seriously attacked only when among defoliated 
trees of other varieties. The red maple and silver maple, if not entirely 
immune to attack, are very nearly so. I know of a number of instances, 
where these trees have retained full foliage in the midst of sugar maples, 
which were completely stripped. 
What are the lasting results from an outbreak of the sort we are 
having? It is hard to say in any case, but with unusual weather com 
