Green Fruit Worms. 571 



probably also at night. When young, they doubtless feed upon 

 the foliage or buds, for, when the fruit is large enough for them 

 to eat, the worms are found to be half grown or more. One of 

 our correspondents writes: "We grafted some young Dutchess 

 pear trees this spring, and have had to watch them continually to 

 keep these worms from destroying the buds." 



We have found some of the caterpillars apparently resting dur- 

 ing the day on a silken web spun on one side of a partly rolled 

 leaf; some of our correspondents have also observed this. We 

 suspect that this is not a normal habit of the insects, for the only 

 occasion we saw it resorted to in our cages was in the case of the 

 caterpillar shown in figure d, plate 4; it was suffering from a 

 serious internal trouble in the form of a parasitic grub which 

 finally came out and fastened the worm to the leaf with its silken 

 cocoon (see the figure). 



Dr. Riley has recorded that the caterpillars can pinch with 

 their little jaws quite sharply, so as to draw a little blood from 

 a tender part. The worms are easily disturbed at their work of 

 feeding on the fruits, for if the tree or limb be suddenly jarn^d, 

 they at once drop to the ground, not spinning down by a silken 

 thread as do the canker worms. 



The parents of these green fruit worms — the moths — are night- 

 flyers, remaining concealed on the bark of the trees or in other 

 secluded places during the day. Most of them appear during 

 September and October, and, hibernating in sheltered places, 

 appear again in March, April and May; some evidently remain 

 in the ground as pupse over winter, the moths not appearing 

 until spring. They are readily attracted tO' lights or sweetened 

 baits at night, and are " often fonnd in maple groves while sugar- 

 ing is going on. Sometimes sap-pails are found in the morning 

 with the surface of the liquid completely covered with the 



moths." 



Their History and Distribution. 



These green fruit worms first attracted serious attention by 

 boring into apples and pears in 1870, in Missouri and Illinois; 

 Dr. Riley also states that he had seen them for several years pre- 

 viously on the foliage of different trees. A newspaper slip, writ- 



