Stratification of tropical rainforests and their arthropods is highly pronounced. I hypothesize that the occurrence of rainforest canopy beetles in the understory is not random but related to the ecology of the taxa, such as feeding guilds and larval development. Therefore, the ecological characteristics of stratum generalists recorded in both the canopy and the lower understory were analyzed. Adult beetles were collected manually and with traps in the northern part of the Amazonian rainforest for a cumulative year. Seventy out of a total of 862 canopy beetle species from 45 families associated with 23 tree species were shared between both strata. The beetle families represented by most species in the canopy and ground samples were Curculionidae, Chrysomelidae, and Carabidae. For Elateridae and Scarabaeidae, the proportion of shared species between the strata was ≥20%. In contrast, the species-rich families (≥20 canopy species) Cerambycidae, Mordellidae, and Buprestidae did not comprise species sampled in both strata. Thus, beetle families comprising many stratum generalists are either largely predatory, or their larvae often develop in the soil.
