UNITED STATES DEPARTMENT OE AGRICULTURE 

 BUREAU OF ENTOMOLOGY 

 Washington, D. C. 



FOREST ENTOMOLOGY BRIEF Ug . December 5, 1923 



BRIEF INFORMATION ON INSECT DAMAGE TO GREEN ASH LOGS AND 

 LUMBER IN THE SOUTHERN ATLANTIC AND GULF STATES, 

 PARTICULARLY IN THE DELTA REGION OF THE 

 MISSISSIPPI RIVER. 



Character and Extent of Damage . 



The principal damage to green ash logs and lumber is due pri- 

 marily to attack by two classes of wood -boring insects, namely, pin- 

 hole borers or ambrosia beetles and wormhole borers. Their habits 

 differ considerably. 



Pinhole borer damage is caused by the adult beetles when they 

 bore holes or burrows in the wood, not much larger than the head of a 

 pin, 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 necessary 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 agencies, 

 which retards drying, such as leaving green logs in moist, shaded places 

 or placing freshly sawed lumber in close piles during the period of 

 insect activity, will offer favorable conditions for attack by insects 

 of this class. 



Wormhole borer damage differs radically from pinhole borer injury 

 in that it is caused by the young forms or grubs and not by the adults. 

 The presence of bark is absolutely necessary for successful infestation 

 by most of the wood-boring grubs, because the eggs and young stages must 

 occupy it before the latter can enter the wood. It usually takes nearly 

 one month, after the eggs have been deposited in the bark by the adult 

 beetles, for the grubs to develop sufficiently to enter the sapwood, 

 where they make large holes. When green logs are left in the woods for 

 a short time after being felled, or the bark is left on the edges of 

 freshly sawed lumber, during the period of insect activity, the wood 

 will be attractive to these borers. 



Under such conditions, damage to the wood by both classes of in- 

 sects may result in a loss of from UO to 50 P e r cent in a very short 

 time . In some instances recently felled timber had to be abandoned and 

 green lumber was reduced in value from the best grades to culls. 



Remedy. 



Damage to infested lumber can be checked, where practicable, by 

 saturating it with a liberal solution of liquid orthodichlorobenzene . 

 Injury to infested logs can be checked, in cases where the grubs are only 



