Overview
Insecta is a class of invertebrates that consists of around 30 individual extant orders. Orders are the fifth taxonomic rank used to classify living organisms, below the rank of class, but above the rank of family. With around 1 million insect species having been formally described and assigned a binomial name, insects are the most diverse group of animals, comprising approximately half of extant species on Earth. The total insect biodiversity has been estimated at around 6 million species. The most diverse orders are Coleoptera (beetles), Hymenoptera, Lepidoptera, Diptera (flies) and Hemiptera. Taxonomists disagree on the exact number of orders, with opinions ranging from 26 to 32 distinct extant orders.