THE FALL WEB-WORM. 



THE FALL WEB-WORM. 



{Hyphantria {Spilosoma) iexior, Harris.) 



Order of LEPIDOPTERA. Family of Artiid^. 



Harris's Treatise, page 357 ; Fitch's Report, No. 88. 



This is the caterpiUar which disfigures with its web, often sev- 

 eral feet in extent, both garden and forest trees in the latter part 

 of the summer and fall. Like other caterpillars of the family of 

 Arctians, to which both this and the preceding species belong 

 they are very indiscriminate feeders. This is the more remark- 

 able as the great majority of insects are very select in their diet, 

 generally confining themselves to a single species of plant, or at 

 most to plants of the same natural family. The Web-worm flour- 

 ishes equally well upon the apple, pear, cherry, both wild and 

 cultivated, shagbark and pignut hickory, black walnut, butternut, 

 elm, ash, and willow, and they bear to be transferred from one 

 kind of tree to another with impunity. I have, this summer, 

 changed them from the apple tree to the black walnut, and vice 

 versa, without their seeming to suff'er any inconvenience. Their 

 range of diet however ha^ its limits. I have tried the experiment 

 of tying nests of these caterpillars upon the common locust, maple, 

 currant and rose bushes, and grape vine. In all these cases the 

 caterpillars extended their web a short distance, but ate but little, 

 and in no case came to maturity. 



When young they eat only the upper surface of the leaves, but 

 when more mature they devour the whole leaf except the larger 

 ribs. They are active caterpillars, and when disturbed, have a 

 habit, especially when young, of showing their dissatisfaction by 

 snapping their heads from one side to another. They do not crawl 

 upon the branches like the Tent-caterpillar, but travel along the 

 threads of which their webs are composed. They inclose within 

 their nests the leaves upon which they feed, extending their web 

 from branch to branch as their necessities require. Late in the 

 season these nests attain a great size, and where there happens to 

 be a number of them on one tree, they will sometimes almost cover 

 a tree of moderate dimensions. A nest of these insects upon an 

 apple tree in my garden, the present feeason, which I left unmo- 

 lested for the purpose of observing their habits, attained an extent 



