![<small>(Image: Grant Recipient or NCPTT)</small> 2002-09](https://webarchive.library.unt.edu/eot2008/20090114211559im_/http://www.ncptt.nps.gov/images/Product-Catalog/250/2002-09-250.jpg)
Termites are a significant structural pest in the United States, costing the public nearly $1.5 billion in damage each year. The bulk of this damage can be attributed to subterranean termites. Historic buildings and structures
are particularly vulnerable to subterranean termite damage, given the traditional use of wood as a building material.
Termite damage to historic buildings is both costly and irreversible and can diminish the historic significance of the structure through the loss of original building fabric. Cultural landscapes are also vulnerable to termite damage. In New Orleans, many of the historic oak trees that add shelter and beauty to the city are threatened by an introduced species, the Formosan subterranean termite, Coptotermes formosanus. This species can construct nests within the dead heartwood of the tree eventually weakening it to the point where it is unstable and falls in bad weather.
Conventional methods for the control of subterranean termite infestations rely heavily on the use of organic (i.e., carbon-based) insecticides to provide a barrier for the exclusion of soil-borne termites from a structure.
Typically, large volumes of liquid insecticide are applied to the soil beneath and surrounding an infested building.
Poisoning the soil is not a sustainable practice and may contaminate groundwater as well as pose health and safety hazards. Moreover, such an approach is not altogether effective. Creating an uninterrupted barrier of
treated soil beneath an existing structure is extremely difficult, and gaps in the barrier invariably allow access to the structure. Also, because the soil treatment only deters termite attack, the vast majority of subterranean termites are unaffected.
Conventional soil treatments often result in physical damage to the structure; they require the drilling of often disfiguring and unsightly
holes in the foundation floor before liquid insecticides are injected into the soil.