PEACH. ROOT THE BORER. THE WORM DESCRIBED. 



113 



cause of the mischief, several of the worms being present in the 

 roots. This, taken in connection with the modification which the 

 habits of the worm undergo when in this situation, 

 is a remarkable fact. Although the plum abounds 

 in gum like the peach, none of this gum exudes 

 from its root when attacked by this borer. The 

 worm, therefore, having no covering to protect it 

 does not erode the bark and nestle upon the out- 

 side of the root of the plum as it does in the peach, 

 but lies under the bark and subsists entirely upon 

 the soft sap-wood of the root. Commencing slight- 

 ly below the surface of the ground it works its way 

 downwards immediately under the bark for a dis- 

 tance of about four inches, forming a long and some- 

 what irregular cylindrical channel. The annexed 

 cut shows this burrow as it appears when the bark is removed from 

 the root. As the worm moves along it packs its castings which 

 appear like a tan colored powder, into the channel behind it. 



This is an important fact, showing that if no peach trees were 

 cultivated in our country this species would still sustain itself 

 without difficulty in the roots of the plum. Indeed, as this insect 

 is a ' Native American,' wholly unknown in the peach trees of 

 other countries, it is quite probable that before the peach was in- 

 troduced upon this side of the Atlantic it bred exclusively in our 

 indigenous species of plums, and has now almost entirely forsaken 

 these and attached itself to this more congenial foreigner. 



The Larva is a naked soft white cylindrical grub, slightly flattened on its 

 under side (of which the left hand figure of the accompanying 

 cut gives a view,) and when full grown measures over half an 

 inch in length and nearly a quarter of an inch in diameter. It 

 is divided into fourteen nearly equal segments by broad shallow 

 transverse constrictions. Its head is shining yellowish red, 

 marked in front with black and at base in the middle with whi- 

 tish, which last is also the color of the throat. Two impressed 

 lines on the face converge and meet each other towards the base 

 of the head and then diverge. Inside of and parallel with these are two slen- 

 der black lines, meeting each other in the form of a letter V. The jaws are 

 black and strongly notched at their tips, forming two sharp equal teeth. The 

 upper lip is blackish with a pale stripe in the middle. The palpi or feelers are 

 conical and two.jointcd, and inside of their base is the apex of the lower jaws, 



[Assem. No. 21 5. J 



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