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New perspectives on the biology of the tropical powderpost beetle, Minthea rugicollis (Walk.)
1994 - IRG/WP 94-10085
Minthea rugicollis (Walk.) is one of the most important pests of seasoned hardwoods in the tropics. The species owes its ubiquity largely to its insidious development within a nutrient-filled environment and also to a strong coevolutionary specialization with its natural habitat, wood. Such an environment provides a buffer to extrinsic fluctuations and accounts for a wider range of tolerance by immature stages to variations in climatic conditions than would otherwise be possible. Aspects of culture methods, characteristic habits and external tolerances are emphasised so as to generate new perspectives in understanding the fundamental biology of this organism and to improve current wood preservation strategies.
F Abood, R J Murphy, R W Berry
Analysing the characteristic role of moisture content for drying and fluid flow in Sitka spruce. - Part 1: The drying process of sapwood and heartwood of two different thickness of Sitka spruce using a kiln. - Part 2: Effects of moisture content on longitudinal permeability of Sitka spruce in vertical variation of the tree
2000 - IRG/WP 00-40173
The characteristic role of the moisture content in Sitka spruce (Picea sitchensis (Bong.) Carr.) that grown in the United Kingdom was examined by this study on the basis of (1) the reduction of moisture content in two different thickness of sapwood and heartwood by kiln drying process, and (2) the effects of moisture content to the longitudinal void volume filled of tanalith-C by the full-cell process from base (1 m) to apex (3 m) of the tree in sapwood zone. Accordingly, conclusions on indication of the drying process of sapwood and heartwood, and vertical variation of longitudinal flow with effects of moisture were listed separately: (1) Comparison of Drying Characteristic of Sapwood and Heartwood: The two different thickness (300x30x30 mm3 and 300x20x20 mm3) of sapwood and heartwood of Sitka spruce was dried using the suggested drying schedule in kiln. The reduction of moisture was schematically diagrammed according to sapwood and heartwood stakes. The reduction of moisture followed the same downward trend that sapwood (S) loses more moisture than heartwood (H) although the small stakes of S and H lost moisture rapidly compared with the large ones. (2) Vertical Variation of Moisture Content and Longitudinal Permeability: The 90 kiln dried defect free sapwood stakes (150x25x25 mm3) of Sitka spruce was taken from base to apex of the trees at 1, 2 and 3 m above ground level. After having the determination of moisture content in each experimental stake, the treatment was carried out by the full-cell process with CCA preservative (Tanalith-C) using a model pressure treatment plant. Significant differences observed among the tree heights from 1 to 3 m showing that slightly increases of moisture content from base to apex and conversely decreases of longitudinal void volume filled by preservative fluid.
Distribution of the three symbiotic protozoa in Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae)
1993 - IRG/WP 93-10010
Six colonies (three each from laboratory and field) of Formosan subterranean termite, Coptotermes formosanus Shiraki, were served for investigating the abundance and distribution of three symbiotic protozoa in the hindgut of workers. The total protozoan number amounted to 6,000-10,000 per a worker, and the order of the abundance of the three protozoa and the proportional distribution of each species in the hindgut were common among the colonies. Pseudotrichonympha grassii Koidzumi was the smallest in number (800-2,200 per a worker) and was preferentially distributed in the anterior part of the hindgut. Holomastigotoides hartmanni Koidzumi was medial in number (1,200-3,000), and the distribution was relatively uniform all through the hindgut. Spirotrichonympha leidyi Koidzumi was the most abundant in number (2,800-5,000) and was found mainly in the posterior part. These results appeared to support that the prominent localization of each protozoan species in the worker´s hindgut could be related to the nutritional metabolism in Coptotermes formosanus.
T Yoshimura, K Tsunoda, M Takahashi