Summary
A comparison was made of termite populations in four different forest habitats along the lower Rio Negro, near Manaus. Three of the habitats were on flood-free elevations while the fourth was periodically inundated by the river's flood. Flood-free primary forest along the river bank had the highest number of species (43 spp.): flood-free secondary forest (capoeira) on the bank had a lower total (34 spp.) due to Man's interference with the environment. A much lesser species richness was found in flood-free primary forest on an island in the Anavilhanas archipelago (19 spp.) due to its ecological isolation from the river bank faunas. Periodically flooded forest (igapó) in the archipelago had the lowest total (12 spp.), being a habitat unsuitable for colonisation by most termites. Less than half as many species occurred in primary forest on the island as were found in an equal area of primary forest on the bank. Due to release from foraging competition with other termites, the density of these 19 island species was far higher than that of those on the river bank and their habitats and foraging ranges were also increased. The termites best adapted to secondary forest, to island existence and to igapó are species of potential pest status in forestry: Coptotermes testaceus and 9 species of Nasutitermes, especially N. ephratae and N. nigriceps.