How many species of insects are there of 2017

There are at least 900,000 species, but many more probably have yet to be discovered. Insects all have bodies consisting of a head, a thorax of three segments, usually three pairs of legs and often one or two pairs of wings. Their heads have compound eyes and long antennae that are sensitive to touch and smell.

good thing- during decomposition the organic molecules in organic matter are broken down into simpler organic molecules that require further decomposition or into mineralised nutrients

bad thing- it can be harmful in crop productivity