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Forest Disturbance Processes

Survival of Woodboring Insects in Heat-Treated Wood

Research Issue

[photo:] firewood being treated and tested.Solid wood packing material and firewood are both important pathways in which native and exotic pests can be spread to new areas.  The risk that this poses, both environmentally and economically, has led to required treatment of these products both among and within countries.  The temperature and time required to kill pests is important for sanitization; however, little research has been done on the efficacy of heat treatments for killing pests in wood.   

Our Research

During 2009-2013, we tested different treatment temperature and time regimes required to kill various woodboring insects in log sections cut from naturally infested trees.  During our studies we examined both hardwood (deciduous) and softwood (conifer) infested material. Survival was studied for emerald ash borer (EAB) and other flathead borers, longhorned beetles, bark beetles, and weevils.  Temperatures and times tested included the ISPM-15 (International Standards for Phytosanitary Measures) standard of 56°C core temperature for 30 minutes.

Expected Outcomes

Our results provide information on the effectiveness of approved heat treatment protocols for killing woodboring insects and provide information on the temperatures and time required to kill specific species. These results are useful to regulatory personnel and resource managers when setting guidelines and determining treatment protocols for sanitizing firewood and other wood products.

Research Results

We found that the lethal temperature required to kill woodboring insects varies considerably among families and even genera. Most insects were killed when subjected to the ISPM-15 temperature treatment of 56°C core temperature for 30 minutes. The most heat tolerant insect we tested was a Chrysobothris sp. (Coleoptera: Buprestidae), in which two individuals survived treatments of 60°C core for 30 minutes. Given this, the current firewood heat treatment approved by the USDA Animal and Plant Health Inspections Service (APHIS) of 60°C core for 60 minutes appears to be sufficient for sanitizing firewood and similar treatment temperatures and times should be considered for all wood products.

Research Participants

Principal Investigators

  • Robert Haack, US Forest Service- Northern Research Station Research Entomologist, Emeritus
  • Toby Petrice, US Forest Service- Northern Research Station Entomologist

Research Partner

Last Modified: March 11, 2016