46 Bulletin 126. 



insect and the proper time to look for them are discussed under 

 its life-history. 



The Story of its Life and Habits. 



Its winter home. — At anj^ time during the winter this stem 

 girdler may be found within the shoots whose tips were cut off in 

 the preceeding May ; three such shoots are shown, half natural 

 size, on the left in figure 17. If such shoots be cut off and split 

 open the condition shown at a, figure 18 will be revealed. Be- 

 ginning at the tip, a tunnel will be found extending down the 

 shoot for from four to six inches ; this tunnel is always packed 

 full of brownish excrement, as shown in the figure. Nearly 

 three-fourths of an inch at the lower end of this tunnel will be 

 found nicely cleaned out and lined with a thin silken cocoon. 

 Within this cocoon inside of the injured shoots the grub or larval 

 stage of the insect passes the winter. In the right-hand shoot at 

 a, figure 18 is shown the cocoon at the lower end of the tunnel ; 

 it has been cut away in the left-hand shoot and the grub is thus 

 revealed. At b, in figure 18 the lower portion of a is shown about 

 two and a half times natural size. The grub or borer is of a 

 glistening straw-yellow color, with the head slightly darker. 

 The thoracic segments are nearly twice as wide as the head and 

 are slightly wider than the others ; they bear six rudimentary 

 feet. From the caudal end of the body there projects upward a 

 peculiar dark brown horny spine, slightly bifid at the tip.* 



Its spring transformatioji . — The grub remains in its silken cell 

 unchanged all winter, but when spring opens in April it changes 

 to the curious whitish pupa shown about twice natural size be- 

 tween the two shoots at b, figure 18. In 1896, the change from 

 a grub to a pupa took place about April 15th, and about two 

 weeks of the insect's life was passed in the pupal condition. In 

 our cages, the pupae began to give forth the adult insect on May 

 2d, and all had emerged by May 6th. As the spring of 1896 

 opened unusually early, the adult insects emerged earlier than 



* A detailed description of the larva occurs in Bull, 28 of the Mass. (Hatch) 

 Expt. Station ; and an excellent figure of it may be found in Insect Life* 

 VIII, p. 389. 



