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^ UNITED STATES DEPARTMENT OF AGRICULTURE 



BUREAU OF ENTOMOLOGY 

 Washington, D. C. 



FOREST ENTOMOLOGY BRIEF 50. December 5, 1923 



BRIEF INFORMATION ON INSECT DAMAGE TO GREEN GUM LOGS AND LUMBER 

 IN THE SOUTHERN ATLANTIC AND GULF STATES AND 

 SUGGESTIONS RELATING TO ITS PREVENTION. 



Character and Extent of Damage . 



The principal damage to southern hardwoods is due primarily to at- 

 tack by tiny wood-boring insects known as pinhole borers or ambrosia 

 beetles, which make holes in the wood not much larger than the head of a 

 pin. They bore holes or burrows in the wood for the purpose of rearing 

 their young. The beetles are attracted to freshly cut trees, logs and 

 lumber only when in a green or moist condition, because moisture is neces- 

 sary for the growth of a so-called ambrosia fungus on the walls of the 

 pinhole burrows on which the beetles and their young live. Therefore, any 

 agency, or combination of them, which retards drying, such as leaving the 

 green logs in moist, shaded places in the woods or placing freshly sawed 

 lumber in close piles during the period of insect activity, will offer 

 favorable conditions for insect attack. Under such conditions logs and 

 lumber may be severely damaged in a few days time and in a few weeks re- 

 duced in value nearly 50 per cent. 



Remedy . 



Damage to infested logs and lumber can be checked, where practical, 

 by submerging in water or saturating with a liberal solution of liquid 

 orthodichlorobenzene . 



Prevention . 



Tne most practical way of protecting green gum logs and lumber from 

 insect injury is to make such slight changes in the methods of management 

 in the woods, in the storing of logs in the mill yard or lumber yard, as 

 is necessary to produce unfavorable conditions for these insects. Such 

 procedure is necessary since they are active from February 15 to November 

 1, causing the most serious damage during warm, damp days of the summer. 

 Occasionally they will appear during mild days of an open winter. 



Protection of green logs during the period of insect activity . 



When prepared for floating - 



(a) Peeling method - to be used during the spring and summer 

 months while the sap is up (April 1 to August 15): 



(l) The cutting and peeling operations should be commenced 

 as soon as the conditions of the swamps are favorable after the gum leaves 

 are full grown. 



