How Much Heat is Enough to Kill Insects?

Information on the ranges of temperature and time required to kill bugs in wood. November 8, 2007

The wood in my solar dry kiln has reached the right moisture content, but I've only hit 130 degrees in the kiln for five to six hours at a time on the hottest days here. I really want to be sure to successfully sterilize (bug kill) this load of wood. I'm thinking about adding an auxiliary heat source into the solar kiln to kick the temperature up to be sure to kill all the bugs. I've read that reaching 160 degrees for an hour is a guaranteed complete bug kill. Does anyone have ideas of good ways to kick up the temperature in the kiln for a few hours? I'm thinking of things like a woodstove and blower, a hot water radiator sort of system, or perhaps a propane space jet heater that would draw air from outside and blast heat inside the kiln. We like the propane heater idea since it seems like the simplest and quickest. Does anyone here have something like this that's working?

Forum Responses
(Sawing and Drying Forum)
From contributor J:
According to the DKOM, powder post beetles are killed at temperatures as low as 125F. They show T ranges of 125-130-140. For the lowest temperature, it takes longer, of course, 46-50 hours. For 140F, 3-7 hours is listed.

From Professor Gene Wengert, forum technical advisor:
Almost all insects will not survive low MCs. The lyctid powder post beetle enters wood at low MCs, so it is unlikely that you have a PPB in your kiln dried lumber that is still in the kiln. With your six hours at 130 F, it sounds like you are well protected.