Insects And Arachnids: What Are The Differences?
There are many differences between insects and arachnids, as well as many similarities. First, both insects and arachnids have an exoskeleton.
In humans and all mammals, the skeleton is found under the skin. The skeleton of human beings protects some vital organs. In turn, the skeleton is protected by muscles and skin.
In the case of arthropods, the skeleton is located outside the body. Therefore, the insects’ exoskeleton protects all their internal organs.
Some arthropods have very resistant exoskeletons; for example, cockroaches. We all had to step on them multiple times to kill them.
Contrary to common belief, venom is not a unique feature of arachnids. Among both insects and arachnids there are poisonous species. The venom, however, is not always strong or lethal in all species. It varies, as mentioned, according to the species and the specimen.
Perhaps the common element between insects and arachnids is that most people find them unsightly. Both insects and arachnids have a strange appearance, making them unattractive by human standards.
However, not all arthropods deserve human hatred. Besides being a vital part of all ecosystems, most of the time insects and arachnids are totally harmless.
In this article we will tell you what the general characteristics of both groups are and the main differences between insects and arachnids.
Insects
Insects are the largest group within the animal kingdom and there are currently more than a million different species on the planet. Thanks to their morphological and physiological characteristics, insects have managed to adapt to almost all environments.
Insects play a very important role in the life cycle of many plant species. For example, they help pollinate fields and allow for more effective decomposition of organic matter.
Over the centuries, insects have helped humans identify certain phenomena. As fans of crime TV series will know , the time of death of an individual can be determined based on the insects in his body.
Unfortunately, insects can also be harmful to humans. Many of them, such as the Aedes aegypti mosquito , are disease carriers.
The arachnids
Arachnids are a large class of arthropods within which scientists have grouped more than 100,000 species. Although scorpions, ticks, fleas and many other animals are arachnids, the vast majority of species in this family are spiders.
The name of the Arachnida classification comes from a Greek myth. According to the myth, Arachne was a beautiful girl very skilled in weaving, skilled like the arthropods that bear her name.
Most arachnids are carnivores that prey on terrestrial insects. Arachnids play a key role in the natural regulation of insect populations by preventing infestations.
Differences between insects and arachnids
The differences between the two classes of arthropods are different, but very noticeable once known. Here is a list of the main differences between insects and arachnids. This way, you will be able to recognize them at first sight.
- Insects are arthropods with three pairs of limbs and one or two pairs of wings. Arachnids are arthropods with four pairs of limbs and never have wings.
- Insects have jaws, while arachnids have chelicerae.
- Arachnids don’t have antennae and insects do.
- The body of insects is divided into three parts: the head, thorax and abdomen. The arachnid is divided into cephalothorax – combined head and thorax – and abdomen.
- Insect blood is colorless, while arachnid blood is bluish.
- Insects have compound eyes, like flies. Arachnids have one to six pairs of simple eyes. This means that both species can look in multiple directions at the same time, but their eyes don’t work the same way.
The differences between insects and arachnids are very obvious when you know how to identify them. It is important to remember that insects play an important role in ecosystems. Therefore, although many times they may seem useless and irritate you, you should know that life on the planet depends on them.
