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''The great majority of young larva? reach the inner bark about 

 September 1st, and have generally all reached it by October 1st. The 

 first half of October is the best time to search for and destroy them. 

 Until that time they have done but little, if any damage, and their 

 location is readily detected by their excretions on the trunk of the 

 tree. They are readily found and despatched by shaving off the outer 

 bark with a sharp knife. My plan of operation has been to go over 

 my orchards each July or August, and with a sharp hoe clean any 

 weeds, grass or other litter and a little soil from around the trunk of 

 each tree, and then in October search carefully and kill the borers. 



"We have often seen it stated that some particular varieties of apple 

 are not injured by the borer. The observing searcher after young 

 borers late in the fall will hardly fail to see the reason why. In all 

 thrifty, late growing varieties, as soon as the young borer penetrates 

 the young bark, its burrow is filled with sap and it is drowned. This 

 is the reason why trees on high, dry, poor soil suffer more than those 

 on rich, deep soil, and why the borers will never be so destructive on 

 the prairies, as the poorer soils of the timber. This also explains 

 why trees in grass are injured more than those kept vigorous by cul- 

 tivation. But it matters not how vigorous the tree, if the young borer 

 is early enough in the season to secure lodgment in the alburnum, or 

 the new layer of sap-wood. The young larva usually works its way 

 downward, striving t6 penetrate into the trunk of the tree lower than 

 the surface of the ground, where it safely passes the winter. The sec- 

 ond season the larva enlarges the burrow mostly vertical^, or up and 

 down the stem of the tree, and during the summer, feeds generally by 

 night in the upper part of it, and in the heat of the day in the lower" 

 part or just under the surface of the soil. By fall its burrow will be 

 from three to six inches long. During the summer the refuse is 

 shoved out through theholes in the bark in pellets shaped like grains 

 of oats; though larger. These we almost invariably find in pairs lying 

 parallel, with their points toward the tree. 



"If we examine our larva at the opening of the second spring of its 

 life we shall find it reduced in length nearly one-half by contraction 

 of the rings of its body from want of food during winter. But it eats 

 voraciously, and by fall is of full size. At this age they are nearly all 

 of a size. During this, their last summer and fall, they do. their 

 principal damage by widening their burrows on every side, destroy- 

 ing the alburnum deposited the year before and often the layer under 

 it. If there is one in a tree at this age, and the tree is not more than 

 one inch and a half in diameter, the borer usually kills it by girdling 

 entirely around it, except about one-fourth of an inch on one side. 

 One borer in a large tree does not materially injure it, but generally, 

 in such trees, there are from two to five, if there are any, and they 

 girdle all around to within one-fourth of an inch of each other's bur- 

 rows, and thus kill the tree. These larvae do not eat the woody fiber 

 of the tree; they tear it down with their sharp, horny, outside pair 

 of jaws, and then select out their proper food with their inner pair of 

 jointed, fleshy jaws, which are armed with long, sharp hooks or teeth. 

 The refuse, close, woody fiber is thrown out. The excrement of the 

 grub is not thrown out, but packed firmly away in some unused por- 

 tion of the burrow. 



