Evaluation of cocoboard resistance against Philippine termites

The resistance of cocoboard (CB) to wood-destroying insects was evaluated under laboratory and field conditions. The resistance of low density CB (LD-CB) (300 kg/m3) and medium density (MD-CB)(700 kg/m3) cocoboard was evaluated using subterranean termites, Microcerotermes losbañosensis Oshima and drywood termites, Cryptotermes dudleyi Light under laboratory conditions. Resistance was rated based on percent damage and weight loss incurred to boards after exposure to the test insect. Field tests on the resistance of CB was conducted above-ground as ceiling or walls at the FRPDI Graveyard Experimental Site. Marine plywood (MPW) samples were used for comparison and tested in the same conditions.The LD-CB and MD-CB were resistantand highly resistant, respectively against M. losbañosensis under laboratory conditions with MPW non-resistant against the same termite species. Likewise, the LD-CB and MD-CB were resistant and highly resistant to C. dudleyi respectively, after the 12-m test period while 19.1 mm MPW and 12.7 mm MPW were resistant to slightly resistant and sustained 21.0% and 65.0% termite damage. Field tests showed that resistance of CB has higher than MPW. The results conform with resistance results in the laboratory suggesting that CB is a suitable material for building construction in terms of natural resistance. Further exposure of board samples is recommended to obtain more data to classify the natural resistance of CB against wood destroying insects under field conditions.