Updated: Oct 1, 2019
The insects comprise a separate class, Insecta - among the arthropods. The first readable fossil record of insects appears in the beginning of the upper carboniferous period - some 320 million years ago.
About 8, 00, 000 species have been found all over the world, more than 3/4 of which belong to four main groups.
Beetles are the most varied insects. Their total number may be as many as 2, 00, 000. The butterflies and moths may total 1, 40, 000 species. There is no hard and fast rules for telling a butterfly from a moth.
Wasps, Bees and Ants - are the third largest of the insect order - 1, 15, 000 species so far identified.
Then the fourth group - Flies, Gnats and Mosquitoes together about 87, 000 species.
There is scarcely a place on this globe that is not home to at least one kind of insect. Among the largest in the world today is the Atlasmoth of our land, which measures 12th from wing tip to wing tip.