Is a spider an insect?

Author: Peter Berry
Date Of Creation: 11 February 2021
Update Date: 12 November 2024
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Why a spider is not an insect
Video: Why a spider is not an insect

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Arthropods correspond to the most numerous phylum within the animal kingdom, so most species on the planet are invertebrates. Within this group we find the subphylum of the Quelicerados, in which its first two appendages have been modified to form structures known as cheliceros (mouthpieces). Furthermore, they have a pair of pedipalps (second appendages), four pairs of legs and do not have antennae. The Quelicerates are divided into three classes and one of them is the Arachnid, of arachnids, which in turn is subdivided into several orders, one being Araneae, which, according to the world catalog of spiders, is composed of 128 families and 49,234 species.

Spiders are, then, a remarkably numerous group. It is estimated, for example, that in a space of 1 acre of vegetation one can find more than a thousand individuals. They usually relate spiders to insects, so PeritoAnimal brings you this article to clarify the following question: spider is insect? You'll find out below.


General characteristics of spiders

Before we answer the question if spider is insect or not, let's get to know these peculiar animals a little better.

spider parts

Spiders' bodies are compact and their heads are not visible, as in other groups. your body is split in two tags or regions: the front or front is called the prosoma, or cephalothorax, and the back or rear is called the opistosoma or abdomen. Tagmas are joined by a structure known as a pedicel, which gives spiders flexibility so they can move the abdomen in many directions.

  • prosome: in the prosome are the six pairs of appendages that these animals have. First the chelicers, which have terminal nails and are endowed with ducts with poisonous glands in almost all species. The pedipalps are soon found and, although they are similar to a pair of paws, they do not have a locomotor function, as they do not reach the ground, their purpose is to have a chewing base and, in some species of males, they are used for courtship and as a copulatory apparatus. Finally, the four pairs of locomotor legs are inserted, which are articulated appendages, formed by seven pieces. So if you ask yourself how many legs does a spider have, the answer is eight. In the prosoma we also find the eyes, which are simple in this group, and are also known as ocelli, small photoreceptor structures for the animal's vision.
  • Opistosome: in the opistosome or abdomen, in general, there are the digestive glands, the excretory system, the glands for the production of silk, the leafy lung, or phylotrachea, the genital apparatus, among other structures.

Spider feeding

Spiders are carnivorous predators, directly hunting prey, chasing it or trapping it in their webs. Once the animal is captured, they inject the venom, which has a paralyzing function. Then they inject enzymes specialized in carrying out the animal's external digestion, to later suck the juice that formed from the captured animal.


Size

Spiders, being such a diverse group, can come in a wide variety of sizes, with small individuals measuring from a few centimeters to the considerably large ones, about 30 cm.

Poison

With the exception of the Uloboridae family, all have ability to inoculate poison. However, for the great diversity of species that exist, only a few can be really harmful to human beings by the action of powerful poisons, which, in some cases, even cause death. Specifically, spiders of the Atrax and Hadronyche genera are the most poisonous to people. In this other article we tell you about the types of venomous spiders that exist.

Is a spider an insect?

As mentioned before, the spider is an arthropod that is found in the subphylum of the Quelicerates, class Arachnida, order Araneae, and has more than one hundred families and 4000 subgenera. Therefore, spiders are not insects, since insects are taxonomically found in the subphylum Unirrámeos and in the class Insecta, so that, although they are distantly related, what spiders and insects have in common is that they belong to the same phylum: the Arthropoda.


Like insects, spiders are abundant on every continent, with the exception of Antarctica. They are present in a wide variety of ecosystems, including some species that have aquatic life, thanks to the creation of nests with air pockets. They are also found in dry and humid climates and their distribution space ranges from sea level to considerable heights.

But spiders and insects have a close relationship in the food chain, since insects are the main food of spiders. In fact, this group of arachnids are biological controllers of insects, essential to maintain the stable populations, as they have highly effective strategies to reproduce themselves, so there are millions of them in the world. In this sense, there are many spiders that are totally harmless to people and that help in an important way to control the presence of insects in urban areas and in our homes.

Examples of some species of spiders

Here are some examples of spiders:

  • Bird-Eating Goliath Spider (Theraposa blondi).
  • Giant Hunting Spider (Maximum heteropoda).
  • Mexican Red Knee Crab (Brachypelma smithi).
  • Raft Spider (Dolomedes fimbriatus).
  • jumping spider (Phidippus audax).
  • Victorian Funnel-web Spider (modest hadronyche).
  • Funnel-web Spider (Atrax robustus).
  • Blue tarantula (Birupes simoroxigorum).
  • Long-legged Spider (Pholcus phalangioides).
  • False Black Widow (thick steatoda).
  • Black Widow (Latrodectus mactans).
  • Flower Crab Spider (misumena vatia).
  • Wasp Spider (argiope bruennichi).
  • Brown spider (Loxosceles Laeta).
  • Calpeian macrothele.

A fear of spiders has long been widespread, however, they almost always have a shy behavior. When they attack a person, it is because they feel threatened or to protect their young. Accidents with these animals are not usually fatal, but, as we mentioned, there are dangerous species that can, indeed, cause death to human beings.

On the other hand, arachnids do not escape being victims of human impact. Large-scale insecticides affect spiders considerably, thus decreasing their population stability.

An illegal trade of some species has also developed, such as, for example, certain tarantulas, which have striking characteristics and are kept in captivity as pets, an improper act, since these are wild animals that should not be kept in these conditions. It is important to bear in mind that animal diversity with its particular beauty and exotic species are part of nature that must be contemplated and protected, never abused or despoiled.

If you want to read more articles similar to Is a spider an insect?, we recommend that you enter our Curiosities section of the animal world.