THE FALL WKIi-WOKM. 



45 



4. Zanihoxylumamericanum M. (Prickly 



Ash.) 

 4. Acer dasycarpum Ehrh. (White or 



Silver Maple.) 

 4. Acerrubrum Wangert. (RedMaple.) 



4. JSsculus flava, Ait. (Sweet Buck- 

 eye.) 



4. 2Esculu8 (jlabra Willd. (Ohio Buck- 

 eye.) 



4. Moras rubra L. (Red Mulberry.) 



'• Trees in the vicinity of the White Poplar and Cottonwood snffe 

 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 clue 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, i. e. 9 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 great number 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 unsuitable 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 I 

 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 ot 

 November, owing perhaps also to the pleasantly warm weather, some 

 few flowers could be observed upon some imported plants belonging to 

 the genus Spiraea and upon the Chinese Bed-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 



