94 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



hazelnut, and osage orange. In addition to the above the writer has 

 observed the larvae feeding on grape, blackberry, cottonwood, Caro- 

 lina poplar, basswood, cedar, lilac, Virginia creeper, snowball, hop- 

 vines, and oats, wheat, alfalfa, red clover, onions, peas, beans, 

 radishes, and rhubarb that were growing in or adjacent to badly 

 infested orchards. This species appears to be able to thrive on the 

 foliage of almost any plant. 



CHARACTER OF INJURY. 



As the manner in which the larvae attack the various host plants 

 differs to a certain degree, it seems advisable to give a rather full dis- 

 cussion of the more important injuries, especially those occurring on 

 fruit trees. 



In the spring, just as the buds are bursting, the larvae begin to 

 gnaw their way out of the eggshells and hard protective covering of 

 the egg masses. (PL XII, fig. 1.) The young caterpillars at once 

 migrate to the developing buds and begin feeding on the unfolding 

 leaves. At first they eat small inconspicuous holes in the unfolded 

 leaves, and at this time the average orchardist is not aware of their 

 presence. After feeding in this manner for a few days the larvae be- 

 come quite conspicuous as they begin to spin fine silken threads from 

 leaf to leaf. Eventually they fold or roll up a single leaf or a cluster 

 of leaves and here they feed for the greater part of the time, though 

 occasionally straying out of their concealment to feed in the open. 

 (PL XIII, fig. 1.) Before the blossoms are fully out, or even before 

 the cluster buds have separated, the "worms" can be observed 

 webbing them together and feeding voraciously. Very often serious 

 injury results before the trees come into blossom. Later in the 

 season the webs produced by the larvae are often quite conspicuous, 

 as is shown in Plate XV. 



As soon as the young fruit has set the larvae cease feeding on the 

 foliage to a large extent, and now fasten one or more leaves to the 

 fruit and within this protection feed greedily, at first eating the skin 

 only, but shortly consuming the pulp and the seeds or stone, depend- 

 ing on the kind of fruit attacked. (PL XIII, fig. 2.) Sometimes 

 young apples are completely devoured except for the stem and a 

 portion of the calyx end. Cases have been noticed where the larvae 

 have completely gnawed through ihe stems, thus causing the fruit 

 to fall to the ground or remain suspended within the feeding nest. 

 Damage done to apples as well as other fruits is usually so severe that 

 the fruit can not outgrow the injury, thus causing a large percentage 

 of unmerchantable or second-class fruit at picking time. Much fruit 

 is also caused to fall prematurely on account of the serious injury 

 inflicted on it when young. The writer has seen several orchards 



