L.G. Kirton’s research while affiliated with University of Reading and other places

The taxonomic status of Coptotermes gestroi (Wasmann), C. havilandi Holmgren, C. travians (Haviland) and C. borneensis Oshima (Isoptera: Rhinotermitidae) is revised. The apparent discrepancy between the reported importance of C. havilandi in countries to which it has been introduced and the region from which it originated is shown to be due to misidentification and taxonomic confusion between C. travians, C. havilandi and C. gestroi. Based on an examination of specimens from Southeast Asia, two species are recognized, namely C. gestroi and C. travians. Coptotermes havilandi, described from imagos, is shown to be the same species as C. gestroi, described earlier from the soldier caste, and is designated a junior synonym. Coptotermes gestroi occurs from Assam through Burma and Thailand to Malaysia and the Indonesian archipelago, and has been introduced into other geographic regions, including parts of North and South America and the Caribbean. It is frequently found damaging wood in buildings, and is often intercepted outside its range in cargo onboard ships and sailing vessels, which is a likely mechanism for its spread to new geographical areas. Coptotermes gestroi has been misidentified in much literature as C. travians. Conversely, C. travians has been misidentified in recent literature in Peninsular Malaysia as C. havilandi, and was redescribed from Borneo as C. borneensis, which is here designated a junior synonym of C. travians. It has a known distribution from Peninsular Malaysia to Borneo, and has not been found infesting wood in buildings. It is envisaged that the resolution of this taxonomic problem will enable the deployment of common pest management strategies for C. gestroi, the primary pest species of Coptotermes originating from Southeast Asia.

Both the plantation forestry and wood preservation industries in the tropical and sub-tropical belts of the world, exemplified by the humid equatorial Peninsular Malaysia, regard termites as major destructive pests of standing trees, various timber products and building timber structures. This paper is a compilation of information on these economically important pests encountered in both plantation forestry and the wood preservation industry in Malaysia, particularly the peninsula, and describes on-going termite research activities to establish practical control strategies for tree and wood protection.

Both the plantation forestry and wood preservation industries in the tropical and sub-tropical belts of the world, exemplified by the humid equatorial Peninsular Malaysia, regard termites as major destructive pests of standing trees, various timber products and building timber structures. This paper is a compilation of information on these economically important pests encountered in both plantation forestry and the wood preservation industry in Malaysia, particularly the peninsula, and describes on-going termite research activities to establish practical control strategies for tree and wood protection.

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 four-year-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.

The effect of excluding termites on wood decay was evaluated in two tropical lowland rain forests in West Malaysia. Billets from the tree, Paranephelium macrophyllum King (Sapindaceae), were placed in either of two designs of lidless stainless-steel trays on the forest floor. The control trays had openings at the bottom and lower sides while the trays designed to exclude termites had the openings covered with stainless-steel mesh. The loss rates of carbon, nitrogen and phosphorus, and the ratios of carbon/nitrogen and carbon/phosphorus, were compared for wood samples from which termites had or had not been excluded. Comparisons were made at yearly intervals over a period of three years. C, N and P were lost over two or three years. The C/N ratio declined over the experimental period, indicating a slower loss of N compared with C. There was a significant difference in the C/N ratios of the wood samples between the two types of trays for one of the forest sites; the ratio was greater when termites were not excluded, indicating that the termites had enhanced nitrogen release from the decaying wood. The advantage of the present termite exclusion method over other methods is discussed.

The incidence of attack by the termite, Coptotermes curvignathus Holmgren, in four- to eight-year-old Acacia mangium forest plantations is examined and discussed in relation to 1) the occurrence of the termite on wood material on the forest floor of plantations and dipterocarp forest, and 2) the severity of attack reported in four-year-old conifer plantations. Although A. mangium plantations had a much greater number of large stumps and logs on the forest floor than dipterocarp forests, due to incomplete clearing and burning of the original forest, numbers of forest floor wood material in which the termite occurred averaged 5.3 per ha and 8.0 per ha respectively for these habitats. The number of living A. mangium trees with infestations averaged 13.3 per ha, while there were no infestations of living trees sampled in dipterocarp forests. The incidence of attack on A. mangium trees was greater than that reported for Pinus caribaea, P. merkusii, P. oocarpa and Agathis macrophylla, but lower than that reported for Araucaria cunninghamii and A. hunsteinii However, reported rates of mortality among these conifers in plantations greatly exceeded that of A. mangium. The results of the study suggest that, although populations of the termite C. curvignathus are neither eliminated nor greatly reduced by the practice of clear felling and burning of wood debris, contrary to current theory, large stumps and logs left behind by this site preparation practice do not contribute much to increases in the termite population. Susceptibility of the tree species appears, therefore, tobe the major factor affecting the incidence of attack and mortality in plantations. It is suggested that this pest be managed by selection of plantation tree species which are less susceptible to attack and planting of susceptible species, such as conifers, at low-risk sites.

The use of corrugated cardboard strips as simple, flexible conduits for leading subterranean termites of the genus Coptotermes from existing infestations into baited receptacles is described. Cardboard strips, cut such that the internal grooves run parallel to the long edge of the strip, provide channels through which termites could readily move. These were dampened and fastened to infestations on stumps, trees or logs and led to cardboard filled receptacles sealed with aluminum foil, placed on or just below the surface of the ground. The technique can be applied to collect termites for laboratory studies or to conduct field evaluation of termite responses to different wood species or different wood preservatives. It would be equally useful in behavioral and ecological studies on termite feeding behavior. The technique combines versatility and ease of use, and proved to be consistently effective in rapidly initiating infestations within the receptacles, even when only a small number of soldiers were seen in the original infestation. It enables termites to be tapped from infestations that would not be accessible to other techniques, and eliminates the problem of chance encounter associated with placing baits close to termite sources.