226 



BARK-BEETLES ; ENGRAVER-BEETLES. 



insects they show their concern at the threatened loss of their 

 most precious possession b}' trying to save it, 'just as bees, when 

 alarmed, fill themselves with honey. 



As far as remedies are concerned, it is evident that any 

 method by which the entrances of their galleries in the bark can 

 be closed, will effectually put an end to the progress of their col- 

 onies, and perhaps the best means to do so is by coating the trunks 

 with dendrolene or "raupenleim."' V^aluable fruit-trees, which 

 have suffered from fire or frost, can not be protected in this man- 

 ner, as the buds, which must be allowed to grow on the trunks, 

 Avould be injured or destroyed. In such cases it is best to plug 

 the holes with a piece of wire, which is inserted as far as it will 

 go and then cut oft'. 



THE PEAR-BLIGHT BEETLE. 



(X yl chorus pyri Peck). 



During the heat of midsummer the twigs of the pear-tree 

 sometimes become suddenly blighted, the leaves and fruit wither, 

 and a discoloration of the bark takes place, followed by the speedy 

 death of the affected part. This trouble is not caused by the well 

 known fire-blight, which is a disease and is of a totally dift'erent 

 character, and is entirely independent of any insect. The injuries 



Fig. 240. — Gallery of Xyleborus xylo^raphus. Say; in hickory; a, b, death, 

 chambers. After Division of Entomology, U. S. Department of Agritnllnre. 



