Plant Ecology 153: 87–107, 2001. © 2001 Kluwer Academic Publishers. Printed in the Netherlands. 87 Invertebrates in the canopy of tropical rain forests

The current state of knowledge of canopy invertebrates in tropical rain forests is reviewed using data drawn, without bias toward taxon, collecting method or biogeographical region, from 89 studies concerned with mass-collecting (>1000 individuals). The review is intended to identify the most serious gaps and biases in the distribution of higher taxa among forest types and biogeographical regions. With respect to knowledge, biogeographical regions can be ranked as Neotropical> Australian> Oriental> Afrotropical. The canopy of lowland wet and subtropical forests has been studied in greater detail, whereas the canopy of lowland dry and montane forests is much less well known. Collecting techniques influence greatly the present knowledge of canopy invertebrates. Invertebrates other than arthropods, often abundant in epiphytic habitats, phytotelmata and perched litter, are virtually unknown. The abundance of several groups, such as Acari, Collembola and Isoptera, is almost certainly seriously underestimated. Densities of invertebrate individuals in the canopy of tropical rain forests appear to be lower than in temperate forests, although invertebrate abundance is dissipated by the high standing-biomass of rain forests. Coleoptera, particularly Staphylinidae, Curculionidae and Chrysomelidae, along with Hymenoptera, Lepidoptera and Araneae appear to be the most speciose taxa in the canopy, and it is probable that this reflects their range of feeding habits and exploitation of rain forests habitats. The distribution of individuals among the major arthropod orders an