﻿10 BULLETIN 11, U. S. DEPARTMENT OF AGRICULTURE. 



are always injurious. Even if they do not kill the trees outright, 

 they impair their vitality, lessen the rate of growth, and render 

 them more susceptible to fatal attacks of destructive insects. 



Insects. 



The only insect enemy of loblolly pine to cause any serious damage 

 in recent years is the southern pine beetle (Dendroctonus frontalis). 

 It is important that this insect be watched for in stands under manage- 

 ment. Whenever detected, steps should at once be taken to keep it 

 under control. Apparently at long intervals, frequently of 20 years, 

 it becomes so abundant as to cause widespread destruction of pine 

 timber, a loss which could be averted in stands under management 

 by proper precautions. The- depredations frequently last several 

 years unless measures are taken to control the insects. Other species 

 of insects often follow in the wake of the Dendroctonus and feed on 

 trees weakened or killed by its attacks. Sometimes they even attack 

 and kill healthy uninfested trees in the same locality. But with the 

 disappearance of the Dendroctonus in any particular locality the 

 other species of beetles disappear also. This does not seem to be 

 due so much to the measures taken to control the Dendroctonus as to 

 the fact that these other insects are unable effectively to attack live 

 pine timber unaided. However, though the southern pine beetle is 

 the only insect causing serious damage to southern pines at present, 

 it is possible that other species might sometimes become sufficiently 

 numerous to cause extensive destruction. 1 



Whenever owners of loblolly-pine forests discover their timber to 

 be dying in small patches and are unable to determine the cause, they 

 should at once communicate with the Bureau of Entomology, U. S. 

 Department of Agriculture. 



Diseases. 



The principal disease to which loblolly pine is subject is that 

 which causes red heart. Mycelia (spawn) of large polyporous fungi 

 infest the woody tissue of the living tree, the hyphae (filaments) of 

 the spawn destroying the walls of the wood cells, causing the wood 

 to assume a reddish color and rendering it very brittle. Red heart 

 is very rare in young loblolly pine — that is, under 75 years of age — 

 but is quite common in old-growth trees from 150 to 200 years old. 

 From the standpoint of future forest management this disease does 



1 For a complete discussion of how to detect insect injury by the southern pine beetle and methods of 

 controlling infestations the reader is referred to Farmers' Bulletin 476, U. S. Department of Agriculture, 

 by Dr. A. D. Hopkins, in charge of Forest Insect Investigations, Bureau of Entomology. Everyone 

 managing loblolly pine forests should secure this bulletin. During 1910 and 1911 the Dendroctonus 

 destroyed a considerable amount of pine timber in the South, though the insect has now been largely 

 brought under control wherever owners of pine tracts have carried out the measures recommended in the 

 publication. 



