Retail firewood can transport live tree pests.

Area of Science:

• Forestry
• Entomology
• Invasive Species Management

Background:

• Untreated firewood can transport destructive insects and pathogens to uninfested areas.
• A national survey revealed over half of retail firewood originated out-of-state, with 50% showing insect infestation evidence.

Purpose of the Study:

• To quantify insect emergence from retail firewood over 18 months.
• To assess the risk of moving native and nonindigenous insects via untreated firewood.

Main Methods:

• Purchased 419 firewood bundles from retailers in Colorado, New Mexico, Utah, and Wyoming (2007-2009).
• Caged firewood bundles to quantify insect emergence over 18 months.
• Identified emerged insects, noting prominent beetle families like Scolytinae and wood borers.

Main Results:

• Live insects emerged from 47% of firewood bundles.
• An average of 11 insects emerged per infested bundle, with peaks up to 520.
• Insects emerged up to 558 days post-purchase, indicating a prolonged risk.
• Pine, fir, and mixed-conifer bundles yielded the most insects, primarily beetles.

Conclusions:

• The risk of moving live insects, both native and nonindigenous, in untreated firewood is substantial.
• Retail firewood should undergo uniformly accepted heat treatment to eliminate insects before distribution.