-- These ambrosia beetles are best known for their damage to fresh-cut
logs and unseasoned lumber. They also readily attack weakened, stressed,
and dying trees and healthy trees with bark injuries. Damage is largely
in the form of degrade.
Insect. -- Adult beetles are black to brown; .1 to .2 inch (3 to
6 mm); elongate and cylindrical with a wide head in Platypus
and cylindrically compact in Xyleborus species. Larvae are white,
slightly curved to curculiform, legless, and .1 to .2 inch (3 to 6 mm)
Injury (figure 26a). -- White to light brown boring dust in small
piles in bark crevices is good evidence of attack. Numerous round holes
about .1 inch or less (1.5 to 3mm) in diameter give entry to branched
or unbranched tunnels which are stained black and extend into the wood.
The lower trunk may sustain hundreds of attacks (figure 26b).
-- The beetles are attracted to wood with a moisture content above 48
percent. They do not feed on the wood, but instead feed upon ambrosia
fungi which they culture within the galleries. In the Gulf States, beetles
are active most of the year. There are two or more generations per year.
-- Maintain tree vigor. Salvage infested timber immediately. Promptly
use logs during summer months. Store logs under water or water spray.
Green lumber is often kiln dried or chemically dipped to prevent attack.