301 Evidence Supporting the Use of Termite Baiting Systems for Long-term Structural Protection (lsoptera) 1 by J. Kenneth Grace2, & Nan-Yao Su 3 ABSTRACT The efficacy of the Sentricon™ Colony Elimination System containing Recruit™ II termite bait (Dow AgroSciences LLC, 0.5% hexaflumuron) in controlling active subterranean termite infestations has been dem- onstrated in numerous studies. This baiting system and other termite baiting systems are now widely used, and generally accepted tools for remedial termite control in North America, Hawaii, and other parts of the world. The role ofbaiting systems in prevention of termite damages and long-term structural protection, however, is more controversial than their use in remedial control. We discuss three lines of evidence in support of the use of baits for long-term structural protection: ( 1) successful control of termite populations with baits in remedial studies allows a conceptual leap to preventative efficacy, since baits target colonies and populations and cannot be evaluated directly for preven- tion in the manner of soil insecticide barriers; (2) field and laboratory studies demonstrate that termite colonies feed on multiple resources and continue to radiate outward from each of those resources in search of additional food, increasing the likelihood of rapid bait discovery; and (3) results of our long-term field studies over the past decade demon- strate that newly invading termites will reuse existing galleries in the soil left by earlier colonies that lead to monitoring stations, were detected in monitoring stations, and were subsequently eliminated without any noticeable evidence of structural infestation or damage. INTRODUCTION The efficacy of the Sentricon rM Colony Elimination System containing Recruit™ II termite bait (Dow AgroSciences LLC, 0.5% hexaflumuron) in controlling active subterranean termite infestations has been dem- onstrated in numerous studies. This baiting system and other termite 1 Paper presented at the Annual Meeting of the International Research Group on Wood Preservation, Kona, Hawaii, May 2000. An earlier version of the manuscript was distributed as IRG Document No. IRG/WP 00-10377. 2 Department of Plant & Environmental Protection Sciences, University of Hawaii, 3050 Maile Way, Room 310, Honolulu, HI 96822. 3 Ft. Lauderdale Research and Education Center, University of Florida, 3205 College Ave., Ft. Lauderdale, FL 33314.