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UNITED STATES DEPARTMENT OF AGRI CULTURE 

 BUREAU OF ENTOMOLOGY 

 Washington, D. C. 



FOREST ENTOMOLOGY BRIEF %. 



December 5, 1923. 



BRIEF INFORMATION ON INSECT DAMAGE TO CYPRESS LOGS AND LUMBER 

 IN THE SOUTH ATLANTIC AND GULF STATES AND SUGGES- 

 TIONS RELATING TO ITS PREVENTION. 



Character and Extent of Damage . 



The principal damage to cypress is due primarily to attack 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 the sapwood and heartwood of trees when deadened 

 or recently felled and to logs and lumber only when in a green or moist 

 condition, because moisture is necessary for the growth of a so-called 

 ambrosia fungxs 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 the deadening of trees during certain seasons of 

 the year, leaving green logs in moist, shaded places in the woods, or plac- 

 ing freshly sawed lumber in close piles during the period of insect activ- 

 ity, will offer favorable conditions for insect attack. Under such condi- 

 tions trees, logs and lumber may be severely damaged within a few days 

 time and in a few weeks reduced in value nearly 50 V eT 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 

 orthodi chlorobenzene . 



Prevention. 



The most practical way of protecting green cypress logs and lumber 

 from insect injury is to make such slight changes in the methods of manage- 

 ment 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 deedened trees . 



The most favorable time to deaden trees is from August J.fj to Sep- 

 tember 5, as is the common practice in many localities. This period, how- 

 ever, may be extended through October and November. Trees deadened 

 (girdled) during this period will be immune, or nearly so, from insect at- 

 tack. Those prepared during August will be ready to float in October. 



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