Resistance of smoked wood to subterranean and dry-wood termite attack

Abstract

Specimens from Sengon (Paraserianthes falcataria), Sugi (Cryptomeria japonica), and Pulai (Alstonia sp.) trees were exposed for 3, 8, or 15 days to the smoke generated during Mangium wood (Acacia mangium) pyrolysis, and their resistance to termite biodeterioration was compared to that of polystyrene-treated or untreated woods. All treated-wood specimens were exposed to subterranean termites (Coptotermes curvignathus Holmgren) and dry-wood termites (Cryptotermes cynocephalus Light) under laboratory conditions. The results showed that: (1) All three untreated woods were classified as class V (or very poorly resistant) to subterranean termite attack. On the other hand untreated-wood specimens of Pulai and Sugi tree were classified as class IV (or poorly resistant) and specimens of Sengon tree as class III (or moderately resistant) to dry-wood termites, based on the national Indonesian standard; (2) for all three wood species, 3-day exposure to Mangium wood smoke increased their resistance to class I (or very resistant) to subterranean termite attack; and (3) smoke treatment for 3 days for Sengon and Pulai wood specimens, and 15 days for Sugi wood specimens was required to increase their resistance to dry-wood termite attack to class I, which is the resistance level characterizing polystyrene-treated woods for all three species.