Key to Insect Orders - Revised

Insects make up the vast bulk of species diversity, with just over a million described species organized into about thirty major subgroups called orders. Orders are in turn divided into families, families are divided into genera, and genera are divided into species. Properly defined; orders, families and genera are each groups of species that have descended from a unique common ancestor, as a result of which they share similar structural characteristics and have certain biological attributes in