THE PEST STATUS OF THE TERMITE <em>COPTOTERMES</em> <em>CURVIGNATHUS</em> IN <em>ACACIA</em> <em>MANGIUM</em> PLANTATIONS: INCIDENCE, MODE OF ATTACK AND INHERENT PREDISPOSING FACTORS

Abstract

The incidence and mode of attack by the termite Coptotermes curvignathus in Acacia mangium plantations were determined in 452 living trees sampled using random plots in one eight-year-old and two fouryear-old plantations. The overall incidence of infestations was 2.2%, while the highest infestation rate in a site was 4.5%. A few predisposing factors on the tree trunk of living A. mangium trees were observed to facilitate entry of C. curvignathus into the wood. These were large pruning wounds, abscission scars resulting from natural pruning and damage by an insect bark borer. Infestations restricted to such injuries were much more frequently encountered than severe attack by C. curvignathus, which is characterised by extensive soil cover constructed by the termite on the tree trunk. However, such localised external termite activity is thought to be an indication of heartwood infestations, which have been frequently reported to occur in A. mangium. Predisposition of trees to heartwood infestations of termites, as a result of heart rot infection caused by fungi, is examined. The pest status of C. curvignathus in A. mangium plantations is discussed, and recommendations are given for minimising losses in different end-uses of the wood.