232 FRUIT INSECTS 



Ihe trunk. Trees that have been kept in strong, healthy condi- 

 tion by proper care and the use of appropriate fertilizers are 

 better able to withstand borer attack. As this pest is readily 

 distributed in nursery stock, one should be careful in setting a 

 new orchard to have all young trees carefully inspected. 



Reference 

 N. J. Agr. Exp. Sta. 15th Ann. Kept. (1894), pp. 550-551. 1895. 



The pear borer {Sesia pyri Harris) occurs throughout the 

 Eastern states and Canada, ranging southward to Florida and 

 Texas. It is a near relative of the peach tree borer. The adult 

 is a clear-winged moth with an expanse of f inch, bluish-black 

 in color, and having the abdomen marked with three yellow 

 bands ; in the female the anal tuft is also yellow. The larvae, 

 which closely resemble those of the peach tree borer, burrow in 

 or just below the bark on the trunk and larger branches of the 

 pear and apple, but do not penetrate the sapwood as is usual 

 in that species. It, therefore, rarely causes serious injury. 



Pear-blight Beetle 



Xyleborus dispar Fabricius 



Sometimes in June the tips of pear and apple branches sud- 

 denly die back as the result of the work of a small Scolytid 

 beetle. The injury is often mistaken for the bacterial disease, 

 pear blight, whence the common name. These beetles belong 

 to that highly interesting group of wood borers known as 

 ambrosia beetles from their habit of feeding, both as larvae and 

 adults, on a peculiar fungus propagated in their burrows and 

 known as ambrosia. They are also sometimes known as wood 

 stainers from the fact that the growth of the fungus blackens 

 the surrounding wood. 



This species occurs in Europe, Northern Asia, the northern 

 United States and Canada ; it infests among other forest trees 



