Relationship of extractive content, ash and basic density of wood to the attack of termites Nasutitermes sp.

Abstract

An important characteristic for the use of wood is its natural resistance. The objective of the research was to evaluate the natural resistance of the species Plathymenia reticulata, Kielmeyera speciosa and Casearia sp. to the attack of Nasutitermes sp termites and relate it to the content of extractives, ash and basic wood density. The basic density was determined in accordance with NBR 11941 (ABNT 2003) and the extractive and ash contents in accordance with TAPPI T 204 and TAPPI T 211 standards, respectively. The food preference test was performed using the Completely Randomized Design (DIC) method. As a result, P. reticulata showed statistical difference in the basic density in relation to the other species that did not differ among themselves, and the ashes did not present a significant difference between the species, at the 5% level of significance. P. reticulata obtained 0.33% of mass loss, 24.54% of extractive and basic density of 780 kg m-³, in addition to presenting the highest ash content of 2.06%. It is concluded that this is the most resistant species, in relation to its chemical and physical constituents. K. speciosa showed the lowest resistance, followed by Casearia sp., having no relationship with the extractive content.