Although it is the Amazon’s birds, mammals, reptiles and amphibians that most travelers hope to capture with their camera lenses, it is the miniature world of the rainforest’s insects which offers some of South America’s most remarkable spectacles.
From butterflies that drink river turtle’s tears, to bioluminescent beetle larvae that glow in the dark, glittering fireflies, venomous caterpillars, poisonous ants, and ants that run collective fungal gardens, the Amazon basin is home to a truly extraordinary array of insect life.
Rainforests have been around for approximately 125 million years, and their relatively constant climate over millennia has resulted in unrivaled species richness, both in terms of the plant life of the forests and the insect species they sustain, and which in their turn function as pollinators.
While it would be impossible to place an accurate figure on their number, some scientists believe that the Amazon rainforest may be home to as many as 2.5 million species of insects, although only a small fraction of that number have been identified and classified.
While the whole of Europe has around 321 species of butterflies, a 5500-hectare survey of Peru’s Tambopata National Reserve showed that this protected natural area is home to at least 1231 butterfly species.
Across the Amazon basin, a single square mile (258 hectares) of rainforest may be home to as many as 50,000 species of insects. In fact, over 90% of the animal species in the forests of the Amazon are insects. Some entomologists calculate that up to 30% of the entire animal biomass of the Amazon basin may be composed solely of ants.
Over the past decade the estimate for the number of insect species thought to inhabit the planet has risen from 2 million to more than 30 million, as a result of intensive research focused on the tropics. In the forests of the Amazon, it is the high canopy where the greatest number and variety of insects is found. And because scientists have only been studying the forest canopy in anything resembling a systematic manner for the past twenty years or so, new species are being discovered all the time. Biologists now believe that more than half of rainforests’ entire animal populations are arboreal, and that the majority of these species complete their life cycles without ever descending to ground level.
Around the world, as scientific methods improve, at least 10,000 new species of insects are being discovered each year, and of that number most are found in the tropical and subtropical forests of the Amazon basin. And, as is the case with other life forms, the insects of the Amazon basin are much larger and more colorful than their counterparts in the world’s temperate forests.
Some 25% of the world’s 2 million described and classified animals are beetles (Coleoptera). One species of Neotropical longhorn beetle found in the rainforests of Venezuela, Colombia, Ecuador, Brazil and Peru can grow up to six inches (15 centimeters) in length. This is the titan beetle (Titanus giganteus), an insect thought to remain at its larval stage for many years before it pupates, and which when fully grown will defend itself by hissing and biting with fearsome mandibles more than capable of slicing into human flesh.