1. Are the legs present?

1a. Legs present ........................... go to 2

1b. Legs absent ..................... go to 21

2.

2a. Body unsegmented, soft, velvety in appearance, with 14-16 pairs of soft stumpy legs and distinct antennae ............................ Peripatus (Onychophora)

2b. Body segmented; if segmentation not apparent then all or some legs jointed ........................................ go to 3

3.

3a. First 3 pairs of legs slender and jointed, the rest of the legs soft and stubby; if soft stubby legs only, then antennae very short .... Insect larvae (go to 29)

3b. All legs more or less uniform, jointed ........................................go to 4

4. How many legs?

5. Are the antennae branched?

5a. Antennae branched, 9 pairs of legs, small (0.5-1.5 mm), eyeless animals, rare .................................................. Pauropoda

5b. Antennae not branched, different appearance ............................... go to 6

6.

6a. 2 pairs of legs on each posterior body segment; body with hard calcified cuticle, cylindrical or flattened ........... ............................... Millipedes (Diplopoda)

6b. Only 1 pair of legs on each body segment, body soft or leathery ................................................... go to 7

7. Look at the mouth parts underneath the head

7a. A pair of robust pincers is present underneath the head; pale yellow to reddish-brown in colour; eyes often present; if eyeless, then very long (30+ pairs of legs)........ Centipedes (Chilopoda)

7b. Similar in shape, but no pincer-like appendages, no eyes, small (3-10 mm), soft white animals with 9-12 pairs of legs ......................... Symphyla

8. Are the antennae and the head distinct?

8a. Antennae and the head distinct; more than 5 pairs of legs ......................... go to 9

8b. Head fused with the thorax, 4 pairs of walking legs + 1 pair of leg-like palps, no antennae ......... go to 10

9.

9a. Body elliptical, flattened dorso-ventrally, 7 pairs of legs, legs all similar in length ............................... Slaters (Isopoda)

9b. Body compressed from the sides, shrimp-like, legs of unequal length ............ Landhoppers (Amphipoda)

10. Is there a distinct constriction (waist) behind the last pair of legs?

10a. Waist present, the body is divided into two parts – the cephalothorax with eyes and legs, and the soft abdomen with silk organs .................... Spiders (Araneae)

10b. The body is globular or elongated, not divided into two parts by constriction ......................... go to 11

11.

11a. Most legs longer than the length of the body, eyes sit close together on a tubercle in the middle of the front part of the body ............... Harvestmen (Opiliones)

11b. Legs shorter than the length of the body, eyes absent (if eyespots present, they are on the sides of the body) .......................................... go to 12

12.

12a. The front pair of appendages enlarged as pincers; ~ 5 mm in size .......... ..... False scorpions (Pseudoscorpionida)

12b. No large pincers, very small animals (0.1-2 mm) ...... Mites (Acari)

13. Are antennae present?

13a. Antennae completely absent (first pair of legs are often extended forward and may be mistaken for antennae) head small and cone-shaped; eyes absent; abdomen ending in a point. Very small (less than 5 mm), almost colourless animals. Rare ........................... Protura

13b. Different set of characters. Antennae present (may be very short) .................................................... go to 14

14. Is the abdomen ending with pincers?

14a. Abdomen ending with pincers (see the images for 15a and 15b) ........................................ go to 15

14b. No pincers, but hairs, small processes, or long "tails" may be present .................................. go to 16

15.

15a. Eyes absent, animals white except for the darker pincers, and always wingless ............................ Diplura (part)

15b. Eyes present, animals light to dark brown; small wing covers may be present .......... Earwigs (Insecta)

16. Is the abdomen ending with long segmented “tails”?

16a. Abdomen ends in 2 or 3 long (longer than ¼ length of the abdomen), clearly segmented thin filaments ........... go to 17

16b. Only short processes or hairs may be present; or the tip of the abdomen without any processes .............................................. go to 18

17.

17a. Body spindle-like, with 3 long segmented filaments (“tails”) at the end of the abdomen. Dorsal surface often covered with hairs or scales ....Thysanura (silverfish and bristletails) (Insecta)

17b. Body elongated with parallel sides, abdomen ends with 2 long segmented processes (these are easily broken); animals white and eyeless. Body not covered with scales ................................... Diplura (part)

18. Are the wings present in any form?

18a. Wings, wing buds, or hardened wing covers present. Body clearly separated into head, thorax and segmented abdomen; compound eyes usually present ................ Adult insects (Insecta)

18b. Wings, wing buds, or hardened wing covers completely absent ................................................ go to 19

19. Look at the mouth parts

19a. Mouthparts are modified into a sucking tube; body segmented, but may be soft, rounded, and segmentation may be indistinct .................... Insects (aphids, mealy bugs, true bugs, thrips) (Insecta)

19b. Mouthparts are not modified into a sucking tube; body clearly segmented ...............................go to 20

20.

20a. Body soft, never with shields of hardened cuticle. Abdomen with 6 segments, antennae with 4-8 segments; . Forked jumping organ often visible on the ventral side of the abdomen. If abdominal segmentation indistinct (globular body ), then forked spring organ always visible. Small (1-5 mm), various colours ........ Springtails (Collembola)

20b. Abdomen with 7-12 segments. Body with shields of hardened cuticle, or head with distinct hardened cover (head capsule). Forked spring organ never present .... Insects (wingless adults or larvae) (Insecta). Go to 29 for common larvae types.

21. Is the shell present?

21a. shell present ..... Terrestrial snails (Mollusca)

21b. shell absent .......... go to 22

22.

22a. Body soft, distortable, flattened or thick, not segmented ......... go to 23

22b. Body long, worm-like, round in cross-section, smooth or segmented ........ go to 25

23.

23a. No tentacles, body very flattened and tapers at both ends ....... Terrestrial flatworms (Turbellaria)

23b. Head with soft retractable tentacles, eyes may be visible on tips of tentacles ....... go to 24

24. Is there a "leaf-vein" pattern on the dorsal side?

24a. Body with a “leaf-vein” pattern on the dorsal side ....... Native NZ slugs (Mollusca)

24b. Leaf-vein pattern absent, body with a soft “saddle” ....... Introduced slugs (Mollusca)

25.

25a. Head capsule present, or dark internal head skeleton present (sometimes hard to see). Body in cross-section round or flattened, always segmented, with 12 or less segments, often with fleshy processes and hairs ........ Insect larvae (go to 29)

25b. Head capsule or head skeleton absent, body round in cross-section, long, worm-like, smooth or segmented. If segmented, with more than 20 segments .......... go to 26

26.

26a. Body not segmented, long and very thin; body cuticle translucent .......... Nematoda

26b. Body segmented ....... go to 27

27.

27a. Very small (5-15 mm), white and somewhat transparent, fewer segments (up to 30 or so) ...... Enchytraeidae (Oligochaeta) (pot worms)

27b. Larger, body pink or brown, very numerous body segments ......... go to 28

28. Is there a distinct saddle (clitellum) in the first half of the body?

29. Common Insect larvae.

29a. Head distinct, legs present. First 3 pairs of legs slender and jointed, the rest of the legs soft and stubby ........ Lepidoptera (butterflies and moths) (Insecta)

29b. No jointed legs; body cylindrical or flattened, sometimes with fleshy processes. Head capsule usually indistinct (internal mouthparts may be visible). If head distinct then the body cylindrical, long and thin ......... Diptera (flies and mosquitoes) (Insecta)

29c. Head distinct; usually 3 pairs of jointed legs; if legs absent then the body thick and chubby, or flattened ........ Coleoptera (beetles) (Insecta)