Arthropods Identification Key

Use the key below to identify your arthropods

Identification Key Used to Identify Orders of Common Arthropods

(adults > 2-5mm in total body length)
Diagram showing arthropod anatomy
1a 6 legs, three body sections Go to 3
1b Not exactly as above Go to 2

2a 8 legs, two body segments, no tail Araneae
2b 10 legs, stinging tail, pinchers on front appendages

3a Wings obvious and/or hard (or leathery) covering. (ladybug) Go to 4
3b Wings absent Go to 11

4a Two wings (or two wings with tiny, vestigal hindwings), no horny or leathery sheath Diptera
4b Four wings (or two wings covered by a horny or leathery sheath) Go to 5

5a Hind-wings partly or entirely covered by horny or leathery sheath (grasshopper) Go to 6
5b. Both pairs of wings are entirely membranous (wasp) Go to 10

6a. Tube-like mouthparts (for sucking not chewing) Hemiptera (true bugs)
6b. Biting/chewing mouthparts Go to 7

7a Body flattened; antennae long and uniformly thin Blattodea
7b. Body rounded or square-like rather than flattened Go to 8

8a. Hind legs (esp. femur) enlarged (drumstick-like) for jumping Orthoptera
8b. Hind femurs not enlarged Go to 9

9a Leathery sheath is short, vest-like and cerci at end of abdomen Dermaptera
9b Leathery sheath capable of completely covering hind wings and no cerci Coleoptera (beetles)

10a Tube-like mouthparts (sucking, not chewing) Homoptera
10b Biting/chewing mouthparts Hymenoptera; Go to 11

11a Elbowed antennae and distinct dorsal bump on slender segment connecting thorax and abdomen Formicidae
11b. Antennae not elbowed or no dorsal bump other Hymenoptera

Download printable images of the arthropods identified above.