Brown rot fungi have been considered to have developed a non-enzymatic degradation system, called Chelator-mediated Fenton (CMF) reaction, during their evolution, while they lost or reduced the number of the genes encoding enzymes involved in the degradation of lignin and crystalline cellulose. The CMF mechanism utilizes hydroxyl radicals generated under the reaction of hydrogen peroxide and ferrous ion, which is thought to be produced by the reduction of ferric ion in wood cell walls. Many candidates for iron-reducing compounds involved in CMF system have been reported so far, but the detailed mechanisms still remain unclear. In the present study, cedar wood chips were decayed by seven brown-rot fungi and one white-rot fungus, and the iron-reducing capacity was investigated. The results suggest that the water-soluble substances produced during the brown rot process contribute significantly to iron reduction, while the residual components of the decayed wood show only a slight iron-reducing capacity.

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Assuming practical use situations, termites were contacted with chemical-treated soil according to the standard laboratory test method by Japan Wood Protection Association to evaluate transfer effect. All termiticides showed a primary transfer effect after 1 day. Resuscitation was observed for chlorantraniliprole, broflanilide, and imidacloprid. Dicloromezotiaz showed the highest secondary transfer effect.

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