subject: Insects And Their Details [print this page] Insects fall under the category of arthropods which have an exoskeleton (chitinous), a segmented body, 3 pairs of jointed legs, 2 antennae and compound eyes. They also possess a 3 part body which comprises of a head, an abdomen and thorax. The exoskeleton is the principle factor limiting the size of arthropods.
The word insect' has its origin from the Latin word insectum' which means cut into sections' as per historic records. History has amazed us with the size of insects. Some fossils have indicated insects during the Paleozoic era to be of enormous size like the gigantic dragonflies which commanded a wingspan of around 22 to 28 inches (55 to 70 cm).
The growth of an insect consists of development involving a series of molts. The stages of growth may vary but almost every insect hatches from an egg. Immature stages of an insect depend on its structure and habitat. This can include a passive pupal stage in groups which undergo complete metamorphosis.
Likewise, insects can lack a pupal stage in cases of incomplete metamorphosis. In these cases, adults get developed in the course of series of nymphal stages. Movement of insects is characterized by flying, walking (crawling in some cases) and movements through water. Some species of insects like the water striders manage to walk on surface of water.
Insects feed on almost anything which includes human beings and plants. Insects form an important carrier of diseases as well. Insecticides are products used to control insects. Along with feeding on humans, insects are capable of destroying crops and even troubling livestock.
They are the only type of invertebrates to have evolved to be able to fly. Insects are considered solitary with the exception of ants, bees and termites which live in large colonies gifting them a social way of life. Some types of insects are ecologically beneficial and provide economic benefit. Bees and silkworms provide honey and silk respectively.
Insects are found in almost all environments, even in water. They form the most varied group of animals on our planet. Mammals and birds form a miniscule composition of species while insects include more than a million species which is more than half of all living organisms. In short, there are more insects and other arthropods than all other living organisms combined.
