34 THE REDWOOD. 



until their legs and wings are fully developed, when, as fully matured 

 adults, they bore their way out through the wood and bark, producing 

 the shot-hole condition, as shown in the illustration. 



It is known that the Redwood bark-beetle flies early in April and 

 attacks the living bark of recently-felled trees, but as 3"et we have no 

 positive evidence that it attacks standing living trees. The fact, how- 

 ever, that a near relative, the Lawson's Cypress bark-beetle, will 

 attack and kill trees, indicates that under specially favorable conditions 

 this species may do likewise. Therefore any 

 unhealthy condition of the young or old trees 

 in which the leaves toward the top turn yellow 

 and reddish brown should be examined for 

 traces of the beetle's work in the bark and at 

 the base of living twigs. 



REMEDY. 



If it should be found that this beetle is at- 

 tacking living trees, its known habit of infest- 

 ing recently-felled trees suggests that it might 

 Fig. 1.— The Redwood bark easily be Controlled by cutting and barking all 

 beetle: aduit-eiiiarged(orig- infested trccs between the 1st of September 

 and the 1st of December, and by providing a few 

 trap trees to attract those beetles that escape. This may be accom- 

 plished by felling a few trees in December. Then after the adults 

 have entered the bark in the spring and the larvae (grubs) are about 

 half -grown, or before they enter the surface of the wood, if the bark 

 is stripped from all the infested parts of the trunk and larger branches, 

 the broods will be destroyed. It will not be necessary to burn the 

 bark thus removed, because the drying of the inner surface will kill 

 the young stages, while some of the natural enemies of the beetle 

 which would otherwise be destroyed by burning might survive to be 

 of service in reducing the numbers of those which are not attracted to 

 the trap trees or which breed in the standing timber. The tops and 

 smaller branches, which can not conveniently be barked, should be 

 burned, but they should first be left until the broods are nearly devel- 

 oped, in order that the parasites and other natural enemies may have 

 time to develop and emerge to continue their good work. It would 

 be best if this material were burned just before the beetles begin to 

 emerge. 



The life history of the Redwood bark-beetle has not been worked out, 

 but the insect is probably double-brooded, the flrst brood emerging 

 about the middle of summer and the other the following spring. If 

 this is true, it is of the greatest importance to protect, so far as pos- 

 sible, the natural enemies of the first luood, in order that they may 

 continue their depredations on the second hrood. 



