About 18 months ago I bought a 17 foot black walnut tree in Salem, Oregon. About a month ago I had it milled, and it is air drying in my barn.
Before milling it, and again recently, I noticed some type of holes in the sap wood from a boring insect/bug. The exit hole is about 1/16th of an inch.
I was unsuccessful in cutting a piece of the wood off and trying to find the culprit. So far it is only eating the sap wood, but the bugs are busily munching the wood and leaving lots of baby cone-shaped sawdust piles. And there are LOTS of them.
I’m afraid they may invade the heart wood. Do you know what type of insect they probably are and how I can get rid of them?
Tonk Fischer
Salem, Oregon
Replies
Sounds like Powder Post beetle. Read all about it at OSU website.
http://www.ent.orst.edu/urban/MG%20Structural.html
PS1 Corvallis
Thanks for the OSU link - this pest may be my problem!
It's possible you no longer have a problem. The holes you're seeing are exit holes. The larva began as a tiny egg laid in the pores of the sapwood. They lived their lives gleefully eating the starch rich sapwood, matured and tunnelled out, pupated into adults, caroused in search of other like minded individuals and started the cycle over again.
They will not infest the heartwood because there isn't enough starch, they will not infest wood below 10% moisture content. Bostrichids and Lyctids need moisture of 12% and above but blessed with an enzyme the others lack Anobiids can survive in dryer wood, as low as 10%.
So, to get rid of them, assuming you still have a problem, dry the wood to below 10%, or raise the temp of the wood above 140 for a a day, or spray the wood with a borate compound like Boracare. Borates are extremely low in toxicity to us warm blooded critters, in fact our bodies need boron and sodium so some will argue there is no toxicity issue whatsoever.
Lee
Thanks for the helpful solutions! I'll keep my eyes open for any additional exit holes and take action if necessary!
Lee.. Is there ANYTHING you do NOT know about wood?? LOL..
I for one love your posts!
Will, you could pack what I know about wood into what the late and great Jon Arno had forgotten. Jon constantly humbled me with his knowledge.Actually, I was researching an article about insects that infest lumber so I came by my knowledge as a result of that research. The article won't be published for my own reasons but I'm happy to have the started manuscript to which I refer at times like these. I'd hoped to write an article about infestation and treatment options but the topic became very squishy since insects in Florida react differently from insects in New Hampshire and so on. I had to bail because it was impossible to write a comprehensive manuscript without sounding like an insecticide label.But nonetheless, thanks, LeeMontanaFest
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