Insect characteristics

Author: John Stephens
Date Of Creation: 1 January 2021
Update Date: 17 December 2024
Anonim
Characteristics of Insects
Video: Characteristics of Insects

Content

Insects are invertebrate animals that are within the arthropod phylum, that is, have an external exoskeleton it gives them great protection without sacrificing their mobility, and they also have hinged appendages. They are the most diverse group of animals on the planet, with over a million species, while many more are discovered each year.

Furthermore, they are mega-diverse and have adapted very well to almost every environment on the planet. Insects differ from other arthropods in that they have three pairs of legs and two pairs of wings, although this last feature can vary. Their size can range from 1 mm to 20 cm, and the largest insects inhabit tropical areas. Keep reading this PeritoAnimal article and you will learn all about the wonderful world and the insect characteristics, from the details of their anatomy to what they feed on.


insect anatomy

The insects' bodies are covered by an exoskeleton composed of a succession of layers and various substances, including chitin, sclerotin, wax and melanin. This provides mechanical protection against drying and water loss. In terms of body shape, there is great variation between insects, which can be thick and fat like beetles, long and thin like phasmids and stick insects, or flat like cockroaches. the antennas they can also vary in shape and be feathery as in some moths, long as in locusts or curled as in butterflies. Your body is divided into three regions:

insect head

Have capsule shape and this is where the eyes, the mouthparts composed of several pieces and the pair of antennas are inserted. The eyes can be composed, formed by thousands of receptor units, or simple, also called ocelli, which are small photoreceptor structures. The oral system is made up of articulated parts (labrum, jaws, jaws and lip) that allow them to perform different functions, depending on the type of insect and their type of food, which can be:


  • chewer type: as is the case with orthoptera, coleoptera and lepidopterans.
  • cutter-sucker type: present in Diptera.
  • sucker type: also in Diptera, such as the fruit fly.
  • chewer-licker type: in bees and wasps.
  • chipper-sucker type: typical of hemiptera such as fleas and lice.
  • Siphon or tube type: also present in lepidopterans.

insect thorax

It is formed by three segments, each with a pair of legs:

  • Prothorax.
  • Mesothorax.
  • Metathorax.

In most insects, the meso and metathorax carry a pair of wings. They are cuticular expansions of the epidermis, and are endowed with veins. On the other hand, the paws are adapted for different functions, depending on the way of life, since terrestrial insects can be walkers, jumpers, diggers, swimmers. In some species, they are modified to capture prey or collect pollen.


insects' abdomen

Is composed of 9 to 11 segments, but the latter is much reduced in structures called enclosures. In the genital segments are housed the sex organs, which in males are the copulatory organs for transferring sperm, and in females are related to oviposition.

Insect feeding

The insects' diet is enormously varied. Depending on the type of insect, they can feed on the following:

  • Juice from plants.
  • Vegetable tissue.
  • Sheets.
  • Fruits.
  • Flowers.
  • Wood.
  • Fungal hyphae.
  • Other insects or animals.
  • Blood.
  • Animal fluids.

If you want to know more about insects, we recommend reading this other article by PeritoAnimal about the 10 most poisonous insects in Brazil.

Insect reproduction

In insects, the sexes are separated and playback is internal. Some species are asexual and reproduce by parthenogenesis, that is, by producing unfertilized female sex cells. In sexual species, sperm are usually deposited in the female's genital ducts during intercourse.

In some cases, sperm are stored in spermatophores that can be transferred during intercourse or deposited on the substrate to be collected by the female. The sperm are then stored in the female sperm library.

many species mate only once in their life, but others may mate several times a day. insects usually lay a lot of eggs, up to more than a million at a time, and can be deposited alone or in groups, and they do so in specific locations. Some species place them on the plant on which the larvae will feed, aquatic species place them in water and, in the case of parasitic species, they lay their eggs in butterfly caterpillars or other insects, where the larva will later develop and have food. Also, in some cases, they can pierce wood and lay their eggs inside it. Other species are viviparous and are born one individual at a time.

Insect metamorphosis and growth

The first stages of growth occur inside the egg, and they can abandon you in a number of ways. During metamorphosis, the insect undergoes transformations and changes its shape, that is, it changes to molt or ecdysis. Although this process is not exclusive to insects, very drastic changes occur in them, as they are related to the development of the wings, restricted to the adult stage, and to sexual maturity. Metamorphoses can vary according to their type and are classified as follows:

  • holometaboles: ie a complete metamorphosis. It has all phases: egg, larva, pupa and adult.
  • Hemimetabolus: it is a gradual metamorphosis with the following states: egg, nymph and adult. The changes are happening little by little and only in the last change are they more remarkable.
  • Ametaboles: there is no differentiation between young people and adults, except for sexual maturity and body size.

Other insect characteristics

in addition to general characteristics of insects mentioned above, these are other peculiarities that present:

  • tubular heart: have a tubular heart through which the hemolymph circulates (similar to the blood of other animals), and its contractions occur due to peristaltic movements.
  • tracheal breathing: they breathe through the tracheal system, an extensive network of thin tubes that branch throughout the body and are connected to the outside through spiracles that allow them to exchange gas with the environment.
  • Urinary system: have malpighi tubules for excretion of urine.
  • sensory system: Your sensory system is made up of different structures. They have hair-like mechanoreceptors, they also perceive sound through tympanic organs that consist of a group of sensory cells. Taste and odor chemoreceptors, sensory organs in the antennae and paws to detect temperature, humidity and gravity.
  • have diapause: they enter a state of lethargy in which the animal remains at rest due to unfavorable environmental conditions. Therefore, its life cycle is synchronized with favorable times when food is plentiful and environmental conditions are ideal.
  • defense method: for your defense, they have different types of coloring, which can serve as a warning or mimicry. In addition, some species may have a repulsive taste and odor, others have stings with poisonous glands, horns for their defense, or stinging hairs. Some resort to escape.
  • Pollinators: they are pollinators of many plant species, which would not exist if it were not for the insect species. This process is called coevolution, when there is mutual adaptive evolution between two or more species.
  • social species: there are social species and, in that respect, they are extremely evolved. They have cooperation within the group, which depends on tactile and chemical signals. However, not all groups are complex societies, many have temporary organizations and are not coordinated. On the other hand, insects such as ants, termites, wasps and bees are extremely organized, as they coexist in colonies with social hierarchies. They are evolved to the point that they have developed a system of symbols to communicate and convey information about the environment or a food source.

If you want to read more articles similar to Insect characteristics, we recommend that you enter our Curiosities section of the animal world.