Special Species

Essential for the Ecosystem — but You Probably Kill Them Almost Every Day

Most people hate them, banishing them from their homes and yards by any means necessary. They've been around since the earliest ecosystems on earth though, and still play a critical role. Can you guess what these fascinating creatures are?

Reviewed by Dr. Becker

Aug 31, 2026 • 4 min read

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STORY AT-A-GLANCE

Scientists completed an unprecedented two-year project that mapped the evolution of insects
Insects arrived on Earth about 480 million years ago, and together with land plants, built the earliest earthbound ecosystems
Five of the oldest insects on Earth include the silverfish, dragonflies and damselflies, cockroaches, and crickets
Insects were among the first creatures to inhabit both land and air, having lived alongside dinosaurs for millions of years before other species adapted to those environments
Despite the vast span of time separating them, insects that lived alongside dinosaurs looked remarkably similar to the insects seen today

Editor's Note: This article is a reprint. It was originally published July 7, 2015.

Not long ago, a collaboration of over 100 researchers from 10 different countries completed a first-time two-year scientific study mapping the evolution of insects. The study was published in the journal Science in November 2014.¹

According to researcher Dr. Bernhard Misof of the Research Museum Alexander Koenig — Leibniz Institute for Animal Biodiversity (AFMK) in Bonn, Germany:

“Insects are the most species rich organisms on earth. They are of immense ecological, economic and medical importance and affect our daily lives, from pollinating our crops to vectoring diseases.

We can only start to understand the enormous species richness and ecological importance of insects with a reliable reconstruction of how they are related.”²

The researchers learned that insects arrived on Earth at the same time as the earliest land-dwelling plants — about 480 million years ago. This suggests that together, insects and plants shaped the earliest earthbound ecosystems.³

The First Creatures to Inhabit the Earth and the Air Above It Were Insects

According to the study, by the time dinosaurs walked the Earth, dragonflies and damselflies had already been here for many millions of years. The researchers also learned that insects grew wings long before any other creature was able to, and their evolution happened at about the same time terrestrial plants began growing vertically to form forests.

Jessica Ware, who also worked on the research team and is an assistant professor of biology at Rutgers University-Newark, says it’s important to understand the history of insects because “Insects are diverse, economically and ecologically important organisms. The biodiversity of insects is huge,” she says.

Life on Earth had its start in the water, but the first creatures to inhabit the land and the air above were insects, according to Ware. “Whatever people do, insects did it first,” she says. “They waged war, they took slaves, they learned to work cooperatively, they flew, they farmed.”

Interestingly, the insects that lived side-by-side with dinosaurs weren’t prehistoric versions of modern bugs, but looked very similar to the insects buzzing around today.

According to researcher Karl Kjer, a Rutgers professor in the Department of Ecology, Evolution, and Natural Resources:

"If you had a time machine and you went back to the Jurassic, we entomologists would recognize all of the insects and we could [classify] them into their proper order. Many of them would look very similar to what we see today."⁴

5 of the Oldest Insects on Earth

Silverfish

According to Kjer of Rutgers, silverfish are early insects that were around before insects had wings. Silverfish are about 420 million years old. Their modern day ancestor first emerged about 250 million years ago, and looks very similar to the first silverfish.
Dragonflies and damselflies

Dragonflies and damselflies appeared on Earth about 406 million years ago, and they looked different from today’s insects. For example, according to Kjer, they had visible antennae.
Cockroaches

Never the most popular bug on the block, the cockroach’s lineage goes back about 230 million years, and according to Kjer, some types are more closely related to termites than other cockroaches.
Crickets

Crickets, katydids, and grasshoppers had a common ancestor that lived just over 200 million years ago, and their lineage goes back even further. Believe it or not, these insects were here before grass was.