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23,972,000 Yen (FY1995 7,413,000 Yen)
Spatial distributions of decomposing beetles and of pollinating beetles were investigated using attractant traps in the Pasoh Forest Reserved in West Malaysia. 1) The balloon-suspended trap system developed in this study was effective to collect canopy insects. 2) Diverse flower visitors were trapped with various floral chemical attractants, among which linalool and methyl benzoate have been recommended for a general survey of flower-visiting insects. 3) Wood-boring beetles(Scolytidae) were abundant and rich in species just above the ground and in the upper layer of the canopy, perhaps reflecting the distribution of weakened or fresh fallen branches, on which they feed and breed. 4) Most of the flower-visiting beetles(Scarabaeidae) were mainly trapped from 10m to 25m above the ground, indicating that they are active in the continuous middle layer of the canopy, where most trees and climbers bear flowers. Mecinonota regia were distributed in the relatively low layer, while Dasyvalgus dohlni was in the upper part of the canopy. 5) No distinct changes in species richness of wood borers was detected perceived among trap sites, but the abundance of a dominant species increased consistently from the core to the boundary in the forest. The beetle was also abundant in the oil-palm plantation surrounding the forest, where it was observed to breed and multiply on leaf stalks of oil palm. It is most likely that there is a large flux of the beetle from the oil-palm plantation into the forest. The population level or dominance of the ambrosia beetles would be a good indicator for the degree of artificial disturbance on primary forests. 6) Ambrosia beetles frequently attacked on the basal area of dead branches on the canopy. They can should accelerate to fall the dead branches down on the forest floor.
Canopy Fauna, Coleoptera, Pollinator, Decomposer, Fragmentaion, Spatial Distribution