The diversity of macromoths in the various fast-growing exotic tree pl
antations and natural secondary forest in Brumas, Sabah, Malaysia was
assessed by means of an annual cycle of light-trap samples. The moth d
iversity in the forest plantations, viz. Acacia mangium, Gmelina arbor
ea, Paraserianthes (=Albizia) falcataria, Pinus caribaea, and in parti
cular Eucalyptus deglupta, was unexpectedly high. Eucalyptus deglupta
showed moth diversity as high as that in the natural secondary forest,
a finding attributed to the fact that the E. deglupta plantation had
a very diverse understorey both in terms of plant species (secondary r
egrowth species) and architecture, and thus supported a more diverse m
oth fauna. Subsidiary samples showed that primary natural forest in th
e neighbouring Danum Valley does not show higher moth diversity compar
ed to the disturbed forest habitats in Brumas, though moth diversity a
t Danum is lower than that recorded in other Bornean primary forests.
The value of plantation forests for conservation of invertebrate diver
sity is discussed, together with the implications for plantation manag
ement strategy.