INSECTS, FUNGI, PLANT DISEASES, ETC. 



117 



seriously injured by the attack of this insect it will be 

 best to root up the plant and burn it, and use the place 

 for some other plant not susceptible to the attack of the 

 Aphis. 



Apple-Tree Borers (Saperda Candida; Chrysobothris 

 femorata, Fab.). — The first insect in its adult form is a 

 beetle, pale brown with two yellow stripes down its back. 

 The borer, or larval stage, 

 is a grub with a large 

 rounded head and sharp 

 jaws. The eggs are de- 

 posited near the base of 

 the tree and the grub bores 

 into the bark as soon as 

 hatched, twelve to eighteen 

 days after the eggs are 

 laid. The borer remains in 

 the trunk of the tree about 

 three years, cutting a tor- 

 tuous channel, sometimes 

 completely girdling the 

 tree and killing it. The latter insect is also a beetle in its 

 parent form, but is somewhat smaller with a greenish- 

 black back and copper color on the under side. The eggs 

 are deposited one at the time in the crevices of the bark 

 on the trunk and larger limbs, and are hatched within 

 two weeks. The grub does not remain in the tree as long- 

 as the saperda, not more than two years, and it conse- 

 quently does not bore as far into the wood. 



Plants Injured. — Apple, pear, and quince. 



Remedies. — The remedy is preventive, because when 

 the insects once reach the interior of the trunk the tree 

 becomes so seriously damaged it will seldom recover. 

 If the grub has just entered and the orifice can be dis- 

 covered a wire run into the hole will soon end the work 



Fig. 18 — Chrysobothris femorata. a, 

 Larva, b, Beetle, c, Head of male. 

 d, Pupa, twice natural size. Chit- 

 tenden, Div. Ent. U. S. Dept. 

 Agri. Cir. 32. 



