What is an Insect?
By Ralph H Maestre BCE
Insect are included in the large phylum, Arthropoda, along with such animals as crayfish, crabs, centipedes, millipedes, spiders, ticks, mites, and several others. All of these are segmented animals with paired jointed appendages, and other structural characteristics in common. More than 75% of all known animals belong to this phylum.
In order to be able to identify an insect properly, you must know something about its structure.
The "skin" or out covering of an insect is a stiff outer skeleton called the exoskeleton. This type of skeleton, of course, restricts growth of the insect once it has hardened. Consequently, the insect must shed its skin or molt in order to grow.
The body of the insect is divided into three parts or regions:
- The Head
- The Thorax
- The Abdomen
The Head, or first body region is equipped with the mouthparts, brains, glands, antennae, and the eyes.
- Insect mouth parts are classified into four general types:
- Chewing mouthparts found in insects such as beetles, cockroaches, and ants.
- Piercing-sucking mouthparts found in insects such as mosquitoes, some flies, bedbugs, and sucking lice.
- Sponging mouthparts found in adult insects such as house flies, blow flies, and flesh flies.
- Siphoning mouthparts found in insects such as butterflies and moths.
The second body region or division is the Thorax and is composed of three sections or segments. Known as the prothorax, mesothorax, and the metathorax. It is in this region that the legs and wings are attached to the insect. One pair per segment along with the muscles that power the legs and wings.
The third body region or division is the abdomen. This area may contain multiple segments which contains the heart, spiracles, digestive system, and the reproductive organs. The spiracles are the opening by which the insect breaths. Some insects have modified ends that form stingers, such as bees and hornets.
Insects develop differently than humans. They don't grow a little at a time. The young don't always look like a small adult. The insect grows in stages. Insects develop from eggs. Egg laying is extremely variable, and the female insect can lay a single egg or many millions depending upon her species. Eggs may be laid individually, or they may be laid in clusters or groups. In some species the eggs hatch inside the female's body and living young are born.
The first group are believed to be the oldest types of insects, such as silverfish, firebrats, and springtails, these are said to develop without metamorphosis. The young look like the adults and have all the structures of the adults only differing in size, color, and sexual maturity.
The second type of development is called gradual metamorphosis. Insects with this type of development go through three stages during their life cycle: egg stage, nymphal stage, and finally an adult stage. Insects in this group change gradually while they undergo a series of molts until they reach adulthood. The nymphs resemble the adults except that they are smaller and have no wings in wing-bearing species. Insects such as cockroaches, crickets, walking sticks, earwigs, true bugs, and lice belong to this group.
The third type of development is the most complex and is has a complete metamorphosis. Insects in this group go through a four-stage process: egg, larva, pupa, and adult. There are great differences between the immature and the adult stages. The larval stage may be associated with entirely different habitat than that of the pupa or adult. The larval stage is generally the extremely active stage during which time the insect feeds voraciously. It stores the energy to help in the development of the pupal stage where the insect undergoes a complete change in structure. It will emerge as adult. Some of the most common insects of this group are the beetles, butterflies, moths, bees, wasps, ants, flies, and fleas.
This is a very basic explanation of insect biology. The complexity of the hormones, reproductive, circulatory, muscular, skeleton and other systems in insects make up Entomology and its many branches of study.
Magic Exterminating has extensive knowledge in everything pest related. To get help with your pest problems in New York City and Long Island, please contact us for a free estimate.