humid areas of their range. Nevertheless, infestations usually occur only when 
unfinished, untreated wood is exposed in a humid environment such as improperly 
stored lumber, in crawl spaces of buildings, or in outbuildings (/298, /299). 
Damage may occur to heartwood if sapwood is attacked, but usually only the 
sapwood is damaged. Wood from both coniferous (softwood) and deciduous (hard- 
wood) trees are attacked; in fact, yellow-poplar sapwood has proved to be a 
preferred species for egg laying, and best for larval growth and survival over seven 
other woods tested (/306, /307). Most structural infestations originate in soft- 
woods that are exposed in crawl spaces (fig. 109), as softwoods are most commonly 
used for building construction. With time and favorable conditions, infestations 
may spread upward to the hardwood flooring, molding, and furniture. Populations 
within infestations increase slowly, and wood has usually been in service 10 or 
more years before attacks are discovered (/304, 1308). Several factors explain this: 
(1) relatively few eggs are laid per female, (2) the life cycle is usually at least 2 
years in favorable woods and may be 3 to 5 years in unfavorable woods, and (3) 
damage is not easily detected until adults emerge and make holes on the exterior 
surface. These factors just discussed, larval feeding primarily in springwood layers 
of softwoods (/30/), and load sharing capacities of complete floor systems indicate 
that control of infestations in crawl spaces can be achieved after attack and before 
structural weakening occurs if done before infestations spread upward (/303). 
F-531251 
Figure 109.—Damage to softwood lumber in crawl 
space of a house. Note the piles of frass as the result 
of feeding by anobiid powderpost beetle larvae. 
Hemicoelus carinatus (Say) is the most common species in structures in the 
Northeastern United States (/086). Its distribution is from Maine to Manitoba 
southward to Kansas and eastward to North Carolina. Both hardwoods and soft- 
woods are attacked, with the preponderance of attacks paralleling the prevalence of 
hardwoods in the region. Host woods include: silver and sugar maples, yellow and 
paper birches, white and northern red oaks, white ash, American beech, and 
American basswood (/084). The frass is loosely packed within tunnels and will fall 
out when damaged wood is gently tapped. The frass contains elongated pellets 
(1087). 
253 
