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NEW YORK STATE MUSEUM 



more irregular, partly frass-filled burrows which frequently run 

 into each other and most effectively girdle badly infested trunks. 

 Our observations indicate a preference on the part of the insect 

 for the thicker bark of the lower portion of the tree, since the 

 borers in this latter situation were nearly twice the size of those 

 found under the thinner bark of upper part of the trunk. It is 



Fig. 6 Work of spotted hemlock borer; note two galleries originating 

 from near a common point ; galleries of adult and larva in section shown 

 in upper corner (natural size, original) 



possible that the latter come from later deposited eggs. The full- 

 grown larvae winter in the galleries and in the spring pupate in 

 shallow cells excavated in the outer bark. The beetles emerge 

 through obliquely oval holes with a major diameter of about one- 

 eighth of an inch. 



