Abstract:

Objective To measure the efficacy of boric acid wood preservatives in the prevention of Coptotermes formosanus (Shiraki) and Reticulitermes speratus (Kolbe) in buildings. Methods A cohort of C. formosanus or R. speratus were subject to timbers or wood blocks treated with 5% or 10% borate preservative by painting or dipping to determine the respective toxicity and residual effect. Results Borate treated wood demonstrated a good resistance effect against C. formosanus and R. speratus, which were dead at both concentrations with either wood treatment approach. C. formosanus were more susceptible to the agent as the subjects demonstrated shorter survival duration. All subjects of C. formosanus died in (12.6±2.4) days and all R. speratus in (16.8±1.7)days as exposed to wood without ageing, both shorter than the time for death of the groups exposed to wood after ageing, (19.1±2.7) days for C. formosanus and (21.8±5.0) days for R. speratus, respectively. The death rate of the control group was lower than 0.1%. C. formosanus was more susceptible to boric acid in view of the resistance effect, as the intactness index of each piece of borate treated wood in that group was higher than 90. The intactness index of wood treated in 5% by painting or 10% agent by either painting or dipping, with or without ageing, remained above 90. In contrast, wood in the control group was seriously damaged with the intactness index as low as 60 and 40, respectively. It was suggested that borate treated wood had satisfyingly stable and long-last toxicity against termites, which was not compromised by ageing. Conclusion Borate wood preservative can be used for wood treatment for effective termite prevention in buildings.

Key words: Boric acid, Wood preservative, Building, Termite, Toxicity

摘要：

目的 研究硼酸木材防护剂对危害建筑物的台湾乳白蚁和栖北散白蚁的预防效果。方法 用涂刷法和浸泡法处理木材，然后采用群体法测定5%和10%浓度的药液对台湾乳白蚁和栖北散白蚁的毒效以及药剂的残效性。结果 用硼酸防虫剂处理后的木块，对危害建筑物的台湾乳白蚁和栖北散白蚁具有良好的防蛀效果，2个浓度、2种处理方法均可导致台湾乳白蚁和栖北散白蚁100%死亡; 硼酸更容易导致台湾乳白蚁死亡，试虫全部死亡时间相对较短; 未经老化处理的木块导致台湾乳白蚁全部死亡时间为(12.6±2.4)d，导致栖北散白蚁全部死亡时间为(16.8±1.7)d; 经老化处理的木块，导致白蚁全部死亡时间较未老化处理组相对长一些; 对于台湾乳白蚁，试虫全部死亡时间为(19.1±2.7)d; 对于栖北散白蚁，试虫全部死亡时间为(21.8±5.0)d; 对照组白蚁死亡率＜0.1%; 而从防蛀效果来看，栖北散白蚁对硼酸更为敏感，全部处理组木块完好值均在90以上; 对于台湾乳白蚁，经5%涂刷处理和10%涂刷处理或浸泡处理的木块，未老化或老化处理，完好值均可达到90; 对照组木块被严重蛀食，完好值分别为60和40。试验结果表明：硼酸木材防护剂对白蚁的毒性并未受到老化处理的影响，具有良好的稳定性和持效性。结论 硼酸木材防虫剂，用于处理建筑物木构件具有良好的防白蚁效果。

关键词: 硼酸, 木材防护剂, 建筑物, 白蚁, 毒性