1 42 OUR SHADE TREES AND THEIR INSECT DEFOLIATORS. 
4, Zanthoxylumamericanum M. (Prickly 4. Aisculus flava, Ait. (Sweet Buek- 
Ash. ) eye.) 
4. Acer dasycarpum Ebrh. (White or 4. Asculus glabra Willd. (Ohio Buck- 
Silver Maple. ) eye.) 
4. Acerrubrum Wangert. (Red Maple.) 4. Morus rubra L. (Red Mulberry.) 
‘¢Trees in the vicinity of the White Poplar and Cottonwood suffered 
most. Even trees usually not injured, as, for instance, the Sugar Maple, 
are often badly defoliated when in such contiguity. 
“This list contains a number of plants not usually injured by these 
caterpillars. In some cases the injury was due to the fact that twigs con- 
taining the web, with its occupants, had been pruned from the tree and 
thrown near plants, instead of being at once burned or otherwise de- 
stroyed. 
‘In other cases the injury is due to the peculiar position of the plant 
injured, 7. e., under a tree infested by the caterpillars. These when 
fully grown commence to scatter, and dropping upon the plants under- 
neath the tree so defoliate it without actually making their home upon 
it. The greatnumber thus dropping from a large tree will soon defoliate 
any smaller plant, even if each caterpillar takes but a mouthful by way 
of trial. Thus Holly, a plant not usually eaten by these insects, soon 
becomes denuded. Other plants unpalatable or even obnoxious to the 
caterpillars are sometimes destroyed by the multitudes in their search 
for more suitable food. 
‘‘Hungry caterpillars leaving a denuded tree in search of food wander 
in a straight line to the next tree, sometimes a distance of 25 feet, show- 
ing that they possess some keen sense to guide them. If such a tree 
offers unsuitabie food, they still explore it for a long time before de- 
serting it. In this manner two columns of wandering caterpillars are 
formed, which frequently move in opposite directions. 
PECULIAR EFFECT OF DEFOLIATION UPON SOME PLANTS. 
‘During the early part of October many trees, mainly apple and pear, 
which had been entirely denuded of their foliage by the caterpillars, 
- showed renewed activity of growth. Some had a few scattered flowers 
upon them, others had one or two branches clothed with flowers, while in 
some few cases the whole tree appeared white. It looked as if the trees 
were covered with snow, since they lacked the green foliage usually 
seen with the blossoms in spring. Some few flowers were also observed 
upon badly defoliated cherry-trees. Even as late as the middle of 
November, owing perhaps also to the pleasantly warm weather, some 
few flowers could be observed upon some imported plants belonging to 
the genus Spirwa and upon the Chinese Red-apple. All these plants 
usually blossom early in spring. The caterpillars having entirely de-. 
foliated the trees produced thus an artificial period of rest, or winter, 
which was followed by'unseasonable budding and flowering. Such a 
