Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub


    ISPM No. 15 presents guidelines for treating wood packaging material used in international trade. There are currently two approved phytosanitary treatments: heat treatment and methyl bromide fumigation. New treatments are under development, and are needed given that methyl bromide is being phased out. Probit 9 efficacy (100% mortality of at least 93 613 test organisms) has been suggested as an evaluation criterion for new wood treatments, and is based on fruit fly research. We question requiring probit 9 efficacy for wood pests (insects, nematodes and fungi) and discuss challenges to meeting this requirement. Instead, we suggest a 3-step, laboratory-based alternative approach. Step 1 involves laboratory experiments (screening) to estimate the lethal dose for the most tolerant stage of each target pest. We consider each infested piece of wood as an experimental unit, not the individual pests, to avoid pseudoreplication. Step 2 requires replicated experiments (with no survivors) at the estimated lethal dose. We suggest a minimum sample size of 60 experimental units, which achieves 0.95 statistical reliability at the 95% confidence level. Step 3 entails studies under simulated operational conditions using wood samples similar in size to wood packaging material and infested to levels that reflect field conditions.

    Publication Notes

    • Check the Northern Research Station web site to request a printed copy of this publication.
    • Our on-line publications are scanned and captured using Adobe Acrobat.
    • During the capture process some typographical errors may occur.
    • Please contact Sharon Hobrla, if you notice any errors which make this publication unusable.
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Haack, R.A.; Uzunovic, A.; Hoover, K.; Cook, J.A. 2011. Seeking alternatives to probit 9 when developing treatments for wood packaging materials under ISPM No 15. EPPO Bulletin 41: 39-45.

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page