To quantity the termites of the Amazon rainforest is generally difficult, because of their discontinuous distribution, i.e. populations are structured in familial groups, the colonies. Besides, they remain hidden most of the time. Last but not least, termites are often difficult to identify by external morphological characters only. On the other hand, some species build conspicuous structures, which helps in both their detection in the field and in their identification.
For instance, wood-feeding Nasutitermes species are relatively easy to find in Amazonian forests; they cover their foraging trails with walls. Some species like N. macrocephalus and N. surinamensis build large, arboreal nests with up to 1000 dm3 in volume10. Nasutitermes colonies are also known for defending extensive territories, with up to 1750 m2 . Other nasute species include the black, lichen-feeding Constrictotermes cavifrons. These termites also build arboreal nests, and are relatively easy to observe during their daylight foraging trips.
Large nasute species with mandibulate soldiers include the ground-foraging Syntermes molestus and S. spinosus. This last one is among the largest termite species; soldiers grow up to 20 mm in length. Syntermes spp. live underground but forage on surface for dead leaves. They are easily disturbed, though. Labiotermes labralis is another common nasute mandibulate, one that builds huge arboreal nests up to 5 m tall and feeds on soil.
Soldierless termites generally live in colonies diffuse throughout the soil, which renders them difficult to see. However, a few species build conspicuous arboreal nests, such as Anoplotermes banksi, a soil-feeding species, and Ruptitermes arboreus, a dead leaf-feeding species. This last one is known for being atypically aggressive for a soldierless termite (they usually flee when in danger), biting and “exploding” on its enemies.