Canopy knockdown of arthropods in exotic plantations and natural forest in Sabah, north-east Borneo, using insecticidal mist-blowing

Canopy knockdown of arthropods using mist-blowing was carried out in Brumas, Sabah (north-east Borneo), in plantations of exotic (non-indigenous) tree species (Acacin mangium, Eucalyptus deglupta, Gmelina arborea, Paraserianthes [=Albizia] falcataria, and Pinus caribaea), plus secondary natural forest and dense understorey within E. deglupta stands. Each habitat had three 1 m(2) samples taken four times in one year. The average arthropod species richness within the stands of the exotic tree species ranged from 27 in E. deglupta, to 68 in natural, secondary forest. The total number of individuals caught ranged from 137 in G. arborea to 1628 in secondary forest. The dense and plant-species rich understorey within E. deglupta stands yielded both higher numbers of species and individuals than the eucalypt trees themselves, indicating the importance of allowing the development of a luxuriant understorey for the enhancement of conservation and biodiversity. Though arthropod biodiversity is reduced by the conversion of tropical forests to plantations, abundance and richness are still substantial in the latter habitats.