APPENDIX. 381 



FOOD-PLANfS. 



Th-e peach-tree borer is par excellence a peach pest, but may also attack 

 both the wild and cultivated varieties of the cherry, the cultivated varieties 

 of the plums or prunes, nectarines, apricots, flowering' almond shrubs, and 

 azaleas. The indications are that its original food-plants may have been 

 both the wild plum and the wild cherry. 



HOW IT SPREADS. 



It can be easily transported for long- distances on infested trees, and thi> 

 is doubtless the way in which it usually reaches new localities. It is doubt- 

 ful if there is a peach nursery today east of the Rocky Mountains that is not 

 more or less infested with the peach-tree borer. It is one of the most seri- 

 ous of the insect pests that are now being sent out by nurserymen. 



APPERANCE OF INFESTED TREES. 



One can usually quickly determine if a peach tree is infested with borers. 

 The work of the borer always causes the tree to exude a larg-e amount of a 

 mucilaginous matter which forms a gummy mass around the infested portion, 

 as shown in Fig. 45. 



Where the peach-tree borer attacks plum or prune trees, however, there 

 is but a slight, if any, exudation of this gummy substance, hence one can 

 not so readily detect its presence on these trees. It is thus more difficult to 

 find the borers in plum or prune trees, and this makes it harder to combat 

 them in these trees. 



THE STORY OF THE PEACH-TREE BORER'S LIFE. 



But few peach growers stop to marvel over the wonderful transformations 

 exhibited by this insect in passing through the four stages — the egg, the 

 "borer" or larva, the pupa, and the adult moth — of its life-cycle. And yet, 

 our more successful fruitgrowers are fast realizing that they must know 

 more, and, in fact, can not know too much, about the lives and habits of their 

 insect foes in order to fight them the most successfully. 



In New York the moths (Fig. 43) begin to appear in the latter part of 

 June and continue to emerge until September. A few hours after emerging 

 the females lay their small, oval, brown eggs (Fig. 50) on the bark of the 

 trunks of the trees from six to eighteen inches from the ground. From 

 these eggs there hatches, in a week or ten days, a minute larva — the young- 

 borer — which at once works its way into a crevice of the bark, and soon 

 begins feeding on the inner layers of the bark. It continues to feed in this 

 manner, gradually enlarging its burrow under the bark, until winter sets in, 

 when it stops feeding and hibernates during the winter, either in its burrow 

 or in a thin hibernaculum made over itself on the bark near the surface of 

 the soil. The winter is always spent as a larva or borer, a few of them 

 being nearly fullgrown, but most of them being- considerably less than one- 

 half grown. In the spring, usually about May 1 in New York, they break 

 their winter's fast and grow rapidly for a month or more, most of them get- 



