Resistência biológica da madeira de eucalipto tratada com CCA-C a cupins subterrâneos em laboratório

This work aimed to evaluate the biological resistance of Corymbia torelliana and Eucalyptus grandis x Eucalyptus urophylla wood treated with CCA-C, against the termite Nasutitermes corniger in laboratory tests. For the treatment of fence posts the full-cell process (Bethell) was employed. The fence posts measured 2.20 meters in length and diametrical classes were of 8 to 10; 10 to 12 and 12 to 14 cm. Thus eight fence posts per class and forest species were selected, and six were treated and two untreated (control). A disk of 2.0 cm thickness at .50 m from the base was cut from each fence post (untreated), to evaluate the basic density and the heartwood and sapwood percentages and the penetration of copper (treated fence posts). Of each disk (treated fence posts) four samples were obtained from the periphery to 1.5 cm (position 1) and 1.5 to 3.0 cm (position 2) to evaluate the retention and degree of deterioration caused by N. corniger termite in the fence post. Tests were carried out with no choice feeding and choice feeding tests. The greatest mass losses in the no choice feeding and choice feeding tests were those with C. torelliana wood. In treated wood termites survived 13 and 9 days to the C. torelliana and E. grandis x E. urophylla woods, respectively. The best results of biological resistance to termites were found for the E. grandis x E. urophylla treated wood in both tests.