564 Report of the Entomologists of the 



they are fully grown by June, when they measure about an inch 

 or a little more in length and may be briefly described as naked, 

 robust larvfe, yellowish white in color and with the head and 

 first segment dark brown. 



When ready to transform to the pupa state, which is very soon 

 after becoming full grown, the borers prepare elongate oval cells 

 either under the bark of the injured root or in the gummy exuda- 

 tion at the entrance of the excavations. Some of the cells may 

 also be found in the ground a short distance from the roots. 

 These cells are just large enough to contain a single borer, and 

 are constructed of pieces of bark, excrement and particles of 

 the soil, held together by woven threads of silk. In these cells 

 the transformation from the larva to the pupa takes place. 

 The pupa state does not last more than a few days, when the 

 mature insects emerge. Thus, in the climate of the northern 

 states, the peach-tree borer is nearly a year in passing through 

 its transformations from tlie egg to the mature insect. 



Preventive and Remedial Measures. 



Preventive. — Preventive measures consist largely in arranging 

 some mechanical obstruction to prevent the depositing of the 

 eggs on the tree, or the application of some poisonous substance 

 to the bark that will be fatal to the young larvie as they bore 

 into the tree. 



Mechanical ohstructions. — These are usually formed by wrap- 

 ping the trunk with paper, rye straw, etc., or mounding earth 

 about the base of the trunk. The first was suggested by Dr. 

 ITarris in 1820. In his treatise on Insects Injurious to Vegeta- 

 tion, p. 254-255, Dr. Harris refers to this method as follows: 

 " Remove the earth around the base of the tree, crush and destroy 

 the cocoons and borers which may be found in it and under the 

 bark, cover the wounded parts with common clay composition, 

 and surround the trunk with a stri[) of sheathing paper eight 

 or nine inches wide, which should extend two inches below the 

 level of the soil, and be secured with strings of matting above. 

 Fresh iii(»rfar should tlu'ii be placed around the root, so as to 



