64 



THE SCOLYTID BEETLES. 



the past century, to which there are numerous references, was more 

 than likely caused by it. It has been more or less active in the States 

 south of Virginia, southward to Texas, since 1902, and in some 

 localities and during some years it has killed a large amount of timber. 

 It is therefore a constant menace to the pine timber of the Southern 

 States. 



EVIDENCES OF ATTACK. 



The first external evidence that living trees are being attacked by 

 this species is the presence of pitch tubes (fig. 22) on the upper to 

 middle trunk, or of reddish boring dust lodged in the loose bark and 



around the base of 

 the trees. If the 

 attack is sufficient 

 to kill the trees, the 

 presence of the in- 

 sect wUl be indicat- 

 ed in. about two 

 weeks by the fading 

 and yellowish ap- 

 pearance of the 

 leaves, and in about 

 a month after the 

 attack the leaves 

 will be yellowish to 

 reddish, all of the 

 bark except that on 

 the base of the 

 trunks wUl be dead, 

 and the broods of 

 the destructive ene- 



FlG. 26.— Table Mountain pine, Mineral County, W. Va., seven years Hiy WUl be ready tO 

 alter it was killed by the southern pine beetle. {Original, from emerge Or will haVC 



^'°"'^™^'' . emerged. After 



the leaves have become reddish' brown practically all of the broods 

 will be out. Positive evidence, however, that the above-described 

 external conditions are caused by this beetle is obtained only by 

 authentic identifi^cation of specimens of the insect or its work taken 

 from the affected trees. The presence of the insect in destructive and 

 dangerous numbers is indicated by frequent patches of dying pine or 

 spruce during July, August, and September, and the sudden death 

 of the timber over large areas will indicate a destructive invasion 

 requiring prompt and radical measures for its control. 



