No. 4.] FRUIT TEEES AND INSECT FOES. 129 



The presence of the caterpillars of this insect is not often of 

 any great importance; but when they become so abundant as 

 to defoliate a tree to any great extent, it is well to check their 

 ravages either by a little hand picking or by spraying with 

 arsenate of lead, which will quickly destroy them. 



The San Jose scale, codling moth, canker worms, bud moth 

 and several others of the insects already considered are as 

 likely to be found on the pear as on the apple, but the pear 

 psylla (Psylla pyricola Forst.) appears to depend almost exclu- 

 sively upon the pear for its food. This tiny insect, less than 

 a sixteenth of an inch long, and without colors to make it con- 

 spicuous, may be abundant in a pear orchard long enough to 

 make its presence seriously felt, and even to cause the death of 

 the trees, without its presence being suspected unless the 

 owner is on the watch for it. It was probably brought to 

 Connecticut from Europe on an importation of young pear 

 trees in 1832, since which time it has spread everywhere through 

 New England and as far west as Michigan and Illinois. 



The insect passes the winter in the winged adult condition, 

 hiding under loose pieces of bark, in crevices, or anywhere it 

 can find protection. After a few warm days in spring the eggs 

 are laid, chiefly near where the leaves of the previous year had 

 been attached to the twigs, and in creases on the bark. The 

 eggs, which are orange yellow at first, are attached to the tree 

 by a short stalk, and are so small that eighty would need to be 

 placed end to end to measure an inch. 



The length of time spent in the egg is dependent upon the 

 weather. If this be warm, the eggs may hatch in two weeks; 

 but if it be cold, the young may not appear for over a month. 

 When they do appear, however, they crawl to some suitable 

 place and begin to suck the sap from the tree, seeming to 

 prefer the angles between the leaf and fruit stems and the 

 twigs to which these are attached; and as larger numbers ap- 

 pear later in the season they "overflow" from these places to 

 the under side of the leaves and on the leaf stalks. While 

 feeding, the young produce quantities of a sweetish, sticky 

 fluid called "honey dew," which drops onto stems, leaves or 

 the ground beneath the tree, and gradually dries. Ants, wasps 

 and bees find this material much to their taste, and gather in 



