358 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 



still in the bark and before they have entered the wood ; and second, 

 by removing the bark from the logs before the larvae have entered 

 the wood. 



The locust borer is a serious and destructive enemy of the black 

 or yellow locust. Its first work is in the inner bark. Later it enters 

 the wood, where its most destructive work is done, either by so honey- 

 combing the wood as to cause the death of branches or small trees, 

 or by injuring the wood for commercial purposes. Hibernating 

 larvae may be killed by spraying the trunks and branches with a 

 strong solution of kerosene emulsion. Except for the purpose of 

 destroying the borers in the wood, cutting should always be done 

 between October 1 and April 1, the bark removed, and the tops and 

 thinnings bunied. When it is necessary to cut trees between May 1 

 and the middle of September the tops should be burned and the 

 logs either barked or submerged in water for a few days before they 

 are shipped or manufactured. 



The painted hickory borer attacks dead and dying hickory, walnut, 

 honey locust, mulberry, and Osage orange, the larval mines often 

 riddling the sapwood and sometimes the heartwood as well. To pre- 

 vent the spread of this species, all cutting of green timber should 

 be done between August 10 and November 1. Timber which must 

 be cut in spring or early summer should have the bark removed and 

 the tops and useless branches burned. 



The black-horned pine-borer is an enemy of dead or dying cedar, 

 juniper, pine, and spruce. Rustic work is specially liable to injury 

 from this source. As a preventive against injuries by this species, 

 cedar, juniper, pine, and spruce should be cut in late summer, fall, 

 or early winter. If cut between Januarj^ and August the trees 

 should be barked when felled. In the case of injuries to rustic work, 

 an injection of bisulphid of carbon and the plugging up of the holes 

 with wax or putty is recommended. 



The cedar-tree borer attacks dead and injured Douglas fir, arbor- 

 vitge. red cedar, redwood, western hemlock, Engelmann spruce, juni- 

 per, alpine fir, giant arborvitae, white fir, bigtree, and Arizona cypress. 

 Like the black-horned pine-borer, it is injurious to rustic work. The 

 usual preventive measures are recommended, i. e., removing the bark 

 from trees when felled, or treating rustic work as recommended for 

 the black-horned pine-borer. 



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