This is a close-up image of a common garden fly. (Photo by Amith Nag Photography/Moment via Getty Images)
As you explore any part of the planet, pay attention and you will find insects. Check your backyard and you may see ants, beetles, crickets, wasps, mosquitoes and many more. There are more species of insects than mammals, birds and plants combined. This fact has intrigued scientists for centuries.
One of the things that biologists like me do is organize all living things into categories. Insects belong to a phylum known as Arthropoda — organisms with a hard exoskeleton and jointed limbs.
All insects are arthropods, but not all arthropods are insects. For example, spiders, lobsters, and centipedes are arthropods, but they are not insects.
Instead, insects form a subgroup within the class Arthropoda called “Insecta,” which is characterized by six legs, a pair of antennae, and three body segments—the head, abdomen, and thorax, which is located between the head and abdomen.
Most insects also have wings, although some, like fleas, do not. All have compound eyes, which means that insects perceive the world in a very different way to humans. Instead of a single lens, they have many: a fly has 5,000 lenses, and a dragonfly has 30,000. These types of eyes, while not very good at seeing clearly, are excellent at sensing movement.
What is a view?
All insects evolved from a common ancestor that lived about 480 million years ago. For comparison, that was about 100 million years before our vertebrate ancestors — animals with backbones — began living on land.
A species is the smallest unit biologists use to classify living things. When people use the terms ant, fly, or butterfly, they are not talking about species, but about groups that may include hundreds, thousands, or tens of thousands of species. For example, there are about 18,000 species of butterflies—think monarchs, zebra swallowtails, and cabbage butterflies.
Species are essentially a group that can interbreed with each other, but not with other groups. A clear example is that bees cannot interbreed with ants.
However, brown-banded and red-banded bumblebees also cannot interbreed, making them different species of bumblebee.
Each species has its own unique scientific name—for example, Bombus griseocollis for the brown-belted bumblebee—which allows scientists to know exactly which species they are talking about.
Sourse: www.livescience.com
