478 



Fruit Tree Beetle. 



dead, and it was exceptional to find them in healthy bark,, 

 which rather confirms the statement in Kollar's Treatise on 

 Insects, " that it is probable that this beetle only attacks trees 

 that are sickly." There seems to be no doubt that this 

 insect has a decided preference for sickly trees and parts of 

 branches where there is the least flow of sap. The larvae have 

 been frequently found in the tips of shoots of trees injured by 

 frost or other weather influences, as well as near scars from 

 canker, knife cuts, and knots. 



It is not clear that the beetle attacks perfectly healthy 

 and vigorous trees, nor, on the other hand, that it does not 

 attack such, and it is certain that the onslaught of these 

 beetles upon a young tree that might be temporarily sickly 

 from some other cause would prevent its recovery and hasten 

 its destruction. 



The fruit tree beetle not only attacks apple trees, but 

 pear, plum, cherry, and peach trees are also frequently 

 infested by it. 



The dying away of the ends of the twigs and smaller 

 branches, and the shrivelling up of the leaves, are signs of 

 infestation. On close inspection, many round holes, of 

 which the diameter is hardly equal to that of an ordinary^ 

 pin's head, will be seen in the bark of badly infested trees i 

 These holes will be found to lead to the surface of the 

 woody parts, upon which will be found channels or grooves, 

 made lengthways up and down in the bark, and between the 

 bark and the wood ; on either side of these are smaller 

 channels, in which larvae are ensconced. 



Life History. 



The female beetle may be seen flying towards the end of 

 April. It bores a hole in the bark of a tree and forms a 

 channel, as described above, about three-quarters of an inch 

 long, in the bark close to the wood, placing its white eggs 

 with some regularity upon either side of this. Larvae come 

 from the eggs in a few days, and begin to feed on the 

 bark, making branch channels nearly at right-angles with 

 the main channel, called in German " Mutter-gang," or 

 mother-passage. At the end of these branch channels the 



