Abstract
Infestations by stem borers in teak (Tectona grandis) and yemane (Gmelina arborea) plantations were
surveyed at seven locations in Sabah, Malaysia in March, 1998. The teak beehole borer (Xyleutes
ceramica) and the collar ring borer (Endoclita aroura) were found to attack teak and yemane. X.
ceramica accounted for most of the boring attacks in teak plantations, damaging 10.3–65.2% of the
planted trees, except at one location where no stem borer attack was detected. The number of past and
present attacks per tree ranged from 0.27–1.28 and 0.01–0.62, respectively. In contrast, E. aroura was
of minor importance, attacking 6.9% or less of the planted trees. Analysis of spatial distribution of
past attacks by the teak beehole borer in young teak stands revealed a contagious pattern. The past
attacks were heavier on bigger trees. Both past and present attacks were concentrated in the lower part
of the trunk, less than 1 m from the ground level. In young stands of yemane, an unidentified lamiine
cerambycid damaged 0.0–14.1% of the trees, whereas the teak beehole borer damaged 7.6–12.2% of
the trees.