Formosan and Native Subterranean Termite Attack of Pressure-Treated SPF Wood Species Exposed in Louisiana


  • Stan Lebow
  • Todd Shupe
  • Bessie Woodward
  • Douglas Crawford
  • Brian Via
  • Cherilyn Hatfield


Borates, CCA, Formosan subterranean termites, Louisiana, native subterranean termites, penetration, retention, shell treatment, SPF


This study evaluated the relative ability of three types of wood preservatives to inhibit attack by Formosan subterranean termites (FST) (Coptotermes formosanus Shiraki) and native subterranean termites (Reticulitermes spp.). The study also evaluated the roles of preservative retention and penetration in preventing termite damage. Sections of boards from six wood species within the Spruce-Pine-Fir species group were pressure-treated with one of four concentrations of a borax-copper (BC) preservative composed of 93% borax (sodium tetraborate decahydrate) and 7% technical copper hydroxide or one concentration of disodium octaborate tetrahydrate (DOT) or chromated copper arsenate (CCA). Specimens were cut after treatment, exposing untreated end-grain in specimens not completely penetrated by preservative. The specimens were exposed above-ground, protected from the weather, at a site with populations of both native and FST near Lake Charles, Louisiana. Specimens were rated for extent of termite attack after 6, 12, and 24 months of exposure. Attack by FST was more severe than that by native termites for all preservative treatments, although this difference was less obvious at higher preservative retentions. For all treatments, termites preferred to attack the center of the end-grain of the specimens where preservative was either absent or at a lower concentration. However, CCA, which had the lowest overall penetration, was more effective than either borate preservative in preventing attack, whereas some DOT- and BC-treated specimens suffered attack even with what appeared to be complete boron penetration. These results indicate that the efficacy of shell treatments in preventing termite attack is a function of the type of preservative. The BC wood preservative protected wood from both native and Formosan termite attack at B2O3 concentrations equivalent to or lower than that of DOT treatments.


Amburgey, T. L., and M. H. Freeman. 1993. Groundline treatments with a water-borne copper naphthenate-boron paste. American Wood-Preservers' Association Proc. 89: 105.nAmburgey, T. L., C. B. Beiter, and S. V. Parikh. 1993. Aboveground field tests to determine the termite and decay resistance of wood treated with TBTO with and without co-biocides. American Wood-Preservers' Association Proc. 89:61-83.nArrango, R. A., F. Green III, K. Hintz, and R. B. Miller. 2004. Evaluating the durability of native and tropical wood species against Reticulitermes flavipes. IRG/WP 04-10539. International Research Group, Stockholm, Sweden.nAWPA. 2003. Book of standards. American Wood Preservers' Association, Selma, AL.nStandard A3-00. Standard methods for determining penetration of preservatives and fire retardants.nStandard C2-02. Lumber, timbers, bridge ties and mine ties—treatment by pressure processes.nStandard C31-02. Lumber used out of contact with the ground and continuously protected from liquid water—treatment by pressure processes.nStandard M2-01. Standard for inspection of wood products treated with preservatives.nStandard T1-03. Use category system: Processing and treatment standard.nBaker, C., C. Wilson, S. M. McFarling, and P. I. Morris. 2001. Pressure treatment of Canadian SPF with heated borate solutions. In Proc. Canadian Wood Preservation Association21:69-78.nChoi, S., J. N. R. Ruddick, and P. Morris. 2004. Chemical redistribution in CCA-treated decking. Forest Prod. J.54(3):33-37.nDrysdale, J. A. 1994. Boron treatments for the preservation of wood-a review of efficacy data for fungi and termites. IRG/WP/94-30037. International Research Group, Stockholm, Sweden.nEisler, T. 1990. Boron hazards to fish, wildlife, and invertebrates: A synoptic review. U.S. Fish and Wildlife Service, Biol. Rep.85(1.20).nGjovik, L. R., and D. R. Schumann. 1992. Treatability of native softwood species of the northeastern United States. Res. Pap. FPL-RP-508. USDA, Forest Serv., Forest Prod. Lab., Madison, WI. 20 pp.nGrace, J. K. 1997. Review of recent research on the use of borates for termite research. In 2nd International Conference on Wood Protection with Diffusible Preservatives and Pesticides. Forest Products Society, Madison, WI.nGrace, J. K. 1998. Resistance of pine treated with chromated copper arsenate to the Formosan subterranean termite. Forest Prod. J.48(3):79-82nGrace, J. K., and R. T. Yamamoto. 1994a. Repeated exposure of borate-treated Douglas-fir lumber to Formosan subterranean termites in an accelerated field test. Forest Prod. J.44(1):65-67.nGrace, J. K., and R. T. Yamamoto. 1994b. Natural resistance of Alaskacedar, redwood, and teak to Formosan subterranean termites. Forest Prod. J.44(3):41-45.nGrace, J. K., R. T. Yamamoto., and M. Tamashiro. 1992. Resistance of borate-treated Douglas-fir to the Formosan subterranean termite. Forest Prod. J.42(2):61-65.nGrace, J. K., R. J. Oshiro, T. Byrne, P. I. Morris, and K. Tsunoda. 2001. Performance of borate-treated lumber in a four-year, above-ground termite field test in Hawaii. International Research Group on Wood Preservation. IRG/WP 01-30265. International Research Group, Stockholm, Sweden.nGreen, F. G III., S. T. Lebow, and T. Yoshimura. 2000a. Inhibition of termite damage by N'N-napthaloylhydroxyamine (NHA): Reticulotermes flavipes (Kollar) vs. Coptotermes formosanus Shiraki. Proc. International Research Group on Wood Preservation, 31st Annual Meeting, Kona, Hawaii, IRG/WP 00-10354.nGreen, F. G III., D. M. Crawford, S. T. Lebow, and T. Yoshimura. 2000b. Relative Toxicity of N'N-napthaloylhydroxamine (NHA) Toxicity Against Eastern Subterranean and Formosan Subterranean Termites in Southern Yellow Pine, Pages 235-238 in Proc. 2nd Annual Conference on Durability and Disaster Mitigation in Wood-Frame Housing. November 6-8, Madison, WI.nKard, B. M., and E. J. Mallette. 1997. Resistance of six wood products used in paneling to Reticulitermes flavipes (Isopetera: Rhinotermitidae).J. Econ. Entomol.90(1): 178-182.nLebow, S. T., C. A. Hatfield, and W. Abbott. 2005. Treatability of SPF framing lumber with CCA and borate preservatives. Wood Fiber Sci.37(4):605-614.nLenz, M., J. W. Creffield, and S. Runko. 2004. Is there a need for re-sealing cut ends of envelope treated softwood framing lumber to protect against attack from Coptotermes spp. (Isoptera)? International Research Group on Wood Preservation. IRG/WP 04-10524. International Research Group, Stockholm, Sweden.nMorales-Ramos J. A., and M. G. Rojas. 2001. Nutritional ecology of the Formosan subterranean termite (Isoptera: Rhinotermitidae)-feeding response to commercial wood species. J. Econ. Entomol.94(2):516-523.nMorris, P. I., J. K. Grace, K. Tsunoda, and A. Byrne. 2003. Performance of borate-treated wood against Reticulitermes flavipes in above-ground protected conditions. International Research Group on Wood Preservation. IRG/WP 03-30309. International Research Group, Stockholm, Sweden.nMorris, P. I., J. K. Ingram, J. N. R. Ruddick, and S. M. Choi. 2004. Protection of untreated wood by adjacent CCA-treated wood. Forest Prod. J.54(3):29-32.nPeters, B. C., and J. W. Creffield. 2003. Envelope treatment to protect softwood timbers from damage by subterranean termites. International Research Group on Wood Preservation. IRG/WP 03-30313. International Research Group, Stockholm, Sweden.nPeters, B. C., and J. W. Creffield. 2004. Susceptibility of envelopetreated softwood to subterranean termite damage. Forest Prod. J.54(12):9-14.nPreston, A. F; P. A. McKaig, and P. J. Walcheski. 1986. Termite resistance of treated wood in an above ground field test. IRG/WP/1300. International Research Group, Stockholm, Sweden.nPreston, A. F, L. Jin, and K. J. Archer. 1996. Testing treated wood for protection against termite attack in buildings. Proc., American Wood Preservers' Association.92:205-220.nRichards, M. J., and R. D. Inwards. 1989. Treatability with CCA and initiation of field performance testing of refractory softwoods. In Proceedings, Canadian Wood Preservation Association. Vancouver, B.C.10:144-178.nShupe, T. F., and M. A. Dunn. 2000. The Formosan subterranean termite in Louisiana: Implications for the forest products industry. Forest Prod. J.50(5):10-18.nSmith, W. B. 1986. Treatability of several northeastern species with chromated copper arsenate wood preservative. Forest Prod. J.36(7/8):63-69.nSmith, W. B., W. S. McNamara, and R. J. Ziobro. 1998. Field performance of CCA-treated timber from the Northeastern U.S. InProc., American Wood Preservers' Association.94:117-118.n






Research Contributions