Introduction to the Insect Key
The key is adapted from Oldroyd (1958) and Chinery (1993), and provides a first step towards identifying an insect specimen. However, due to the range of variation within many insect Orders, it is impossible to cover all contingencies and the key will not track down unusual and difficult species. For these you will need to consult a reference book of entomology or scan through the listing and descriptions of insect Orders on this site.
CRUSTACEA
MYRIAPODA
ARACHNIDA
INSECTA
MINOR & EXTINCT
CLASSES
Onychophora
Tardigrada
Pentastomida
Pycnogonida
Trilobita
Discover Life | All living things | Insect orders
Discover Life Insect Order determination chart
This simple key is not meant to take the place of a comprehensive identification key. It is provided as a reference to compare some, not all, of the insect orders.
Tips: Only adult arthropods are included, and certain uncommon orders are not included. To use a key, read both descriptions in a couplet (for instance, 1a and 1b). Decide which sounds most like your critter, and move to the next couplet indicated. Should you reach a dead-end, use the numbers in parentheses to backtrack until you reach a couplet that you felt unsure about, and try following the other path. Some orders are found more than once in the keys, because the arthropods occur in different forms.