Evaluation of Lahar Barrier to Protect Wood Structures from Philippine Subterranean Termites
Menandro N. Acda
Department of Forest Products and Paper Science
College of Forestry and Natural Resources,
University of the Philippines Los Banos
College, Laguna, Philippines
Volcanic debris consisting of a sandy aggregate (lahar) from Mt. Pinatubo Central Luzon, Philippines was used as physical barrier to prevent tunneling and penetration of Philippine subterranean termites into a small wooden structure. The protective barrier consisting of mixed lahar particles was installed beneath floor and concrete foundation walls. Regular inspections were made over a five year period to determine signs of termite damage inside and outside of the structure. Results showed that Philippine subterranean termites were unable to penetrate the 5.0 cm thick layer of 1.18 to 2.40 mm lahar particles from the underground soil. The structure remained in good condition with no sign of termite damage to the wooden interior. The study indicated that lahar barrier could be used to protect wooden structures from entry of subterranean termites and offer a non-chemical alternative to commercially available termiticides.
The Philippines is located in a region where subterranean termites are widely distributed and causes substantial damage to homes and wooden structures (Yudin 2002; Acda 2007). Four species of subterranean termites, viz, Coptotermes gestroi Wasmann (formerly known as Coptotermes vastator Light), Nasutitermes luzonicus Oshima, Macrotermes gilvus Hagen, and Microcerotermes losbanosensis Oshima are of economic importance and considered serious structural pest in the Philippines (Acda 2004). These species attack wood buried in or in direct contact with the ground and their activities result in early replacement and reduction of service life of wooden structures. Termite control methods such chemical barrier, baiting and dusting are available in the Philippines. Both repellent and non-repellent termiticides are currently being used for termite control. However, cost of treatment and health risk prevented homeowners from availingtermite control services in the Philippines (Acda 2013).. . . . . . . . . . . . . . . . . . .
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