INSECT ENEMIES OF WESTERN FORESTS 205 



tions adults may appear much earlier. Small round holes in the 

 wood from which fine powder exudes are a good indication of their 

 presence. 



Favorable conditions for attack are made when the sapwood 

 of fine-quality hardwoods, especially of hickory, ash, and oak, is 

 allowed to season for 2 or 3 years in undisturbed piles. Accumula- 

 tions of old stock, refuse, and useless material greatly increase the 

 hazard of infestation. Species of hardwood ordinarily not subject 

 to the attack of these insects will, if piled with more favorable 

 host species, share the damage of infestation. It is therefore, evi- 

 dent that proper methods of handling will do much to prevent 

 these destructive pests from becoming established. Material should 

 be inspected and rehandled annually, and all sapwood refuse, as 

 well as stock showing signs of infestation, should be burned. 

 Woods of different species should be piled separately and should 

 be classified according to age of seasoning, in order that a con- 

 stant turnover in yard stocks may be maintained by utilizing or 

 disposing of the longest-seasoned stock first. The use of heartwood 

 instead of sapwood, for piling sticks in the yard also helps to 

 reduce the breeding ground. Kiln drying and steaming under pres- 

 sure have produced gratifying control. An undesirable feature of 

 the steam-pressure methods is that it is liable to lower the struc- 

 tural strength of the wood, and also there is danger of causing 

 discoloration. 



Great care needs to be taken in storage yards to prevent infes- 

 tation from developing before the sapwood of hardwoods is treated 

 with a filler, painted, or varnished and thus protected. Badly in- 

 fested stocks of tool handles, oars, or building material should be 

 burned. If lightly infested they can be treated by soaking in kero- 

 sene or by applying liberal doses of crude liquid orthodichloro- 

 benzene, either undiluted or with as much as 8 parts of light fuel 

 oil, or a 5-percent solution of pentachlorophenol in light fuel oil. 



Where it is desired not to mar the finish of floors or furniture, 

 these may be treated with a 9-to-l mixture of turpentine and 

 kerosene. 



Stout's bostrichid (Polycaon stouti Lee.) is a large black beetle, 

 about % inch long with prominent mandibles. The larvae bore in 

 the wood of various hardwoods such as oak, California laurel, ma- 

 drone, alder, maple, and others in California and Oregon. There 

 are several records of these large beetles having emerged from 

 polished table tops where these native woods were used as a base 

 for veneer. A smaller brown species, Polycaon confertus Lee, also 

 mines in the wood of these and other broadleaved shade and fruit 

 trees in California and Oregon, and is sometimes responsible for 

 the extensive killing of twigs and branches. 



The lead cable borer (Scobicia declivis (Lee.)) (28) feeds in all 

 sorts of seasoned hardwood, including oak, maple, and California 

 laurel. It has been particularly destructive in boring into alcohol 

 or wine casks and into lead telephone cables. The adults are cylin- 

 drical dark-brown or black beetles about y 4 inch in length and 

 have the head retracted under the thorax, giving them the appear- 



