Many people find insects creepy, but the living world that we humans inhabit could not survive without insects.

A member of the Anthribidae family, this fungivorous beetle is associated with decaying trees in mature tropical forests. Adults feed on fungi, while larvae live on the trunks of dead trees. Image by Brian Brown/Los Angeles County Museum of Natural History.

Dalton de Souza Amorim, a researcher from the University of São Paulo, explains why insects are important:  

“They appeared more than 400 million years before humans. They took part in the evolution of natural environments and are vital in the processes of recycling and maintaining ecosystems by controlling populations of other animals and plants, pollinating, and serving as food for other species. Without insects, there would be no life in terrestrial environments as we know it today.”

There are more species of insects than there are of any other kind of animal.  Entomologists are scientists who study insects. They describe thousands of new species of insects each year – they give them scientific names and they write scientific papers about what the insects look like and what is known about them.

One of the areas of greatest known insect diversity (meaning lots of different kinds of insects) is the Amazon rainforest in South America. In 2017 a team of scientists from Brazil and the Natural History Museum of Los Angeles County carried out a large study of insect diversity in the Amazon.

This research took place at the National Institute for Amazonian Research’s (INPA) Tropical Forestry Experimental Station in the Amazonas state near Manaus, Brazil.  The research station has a special feature that is useful for studying insects, a metal tower more than 50 m (164 ft) high! This tower is in an area of rainforest preserved for research use.

Researchers at work. Image by Dalton Amorim.

The research team set up five large nets on the tower’s platforms, starting at ground level and then every 8 m up from there. The highest net was located 32 m (105 ft) above the ground. This highest net was several meters above the forest canopy (treetop layer). 

The nets would catch insects flying through the forest at the different levels. And the insects would then fall into traps. The trapped insects were then stored in containers of alcohol. Every 15 days the insects in the traps were collected, and this process went on for 13 months. 

The scientists collected a lot of insects – almost 38,000 individual insects were collected in the first 2-week trapping session.

There are plenty of diverse bees in the rainforest, as well as flowers for them to visit. This copper-colored species was collected at the top of the tower, at 24 meters high. Image by Brian Brown/Los Angeles County Museum of Natural History.

Once the insects were collected, they had to be identified, and that took a lot of work by a lot of people.  It took 35 experts almost three years to sort through and identify insects collected from the first trapping session.

This insect is part of a group close to treehoppers (Membracidae), which feed on plants. It uses its body shape and color as camouflage against its predators. Image by Brian Brown/Natural History Museum of Los Angeles County.

One of the major discoveries from this project was that 60% of the insect diversity was found above ground level. That means that if scientists had only studied the types of insects found near the ground, they would have missed the majority of insects present in that patch of rainforest.

The research team determined that there are tens of thousands of insect species present in the upper layers and canopy of the forest at just their study site. 

Across the whole Amazon rainforest there are likely millions of species of insects in the upper levels of the forest that are yet to be discovered.

To read more about this interesting research, visit Mongabay.com:

https://news.mongabay.com/2022/04/the-amazing-and-unknown-diversity-of-insects-living-in-the-amazon-canopy/?fbclid=IwAR1lslf79A4VPzK7TncKVnDXYI693GBHrOvnzkjnhGo2UFfUoP_JzzN46x8

Citation for the research paper discussed in this article:

De Souza Amorim, D., Brown, B. V., Boscolo, D., Ale-Rocha, R., Alvarez-Garcia, D. M., Balbi, M. I., … Rafael, J. A. (2022). Vertical stratification of insect abundance and species richness in an Amazonian tropical forest. Scientific Reports12(1), 1734. doi:10.1038/s41598-022-05677-y