1a

1a. Numerous secondary setae present.....................................23

1b. Secondary setae absent or not very abundant; spines may or may not be present....................................................................... 2

2a. Subdorsal filaments present on at least T2 and A8.

Head and body otherwise smooth.............Nymphalidae (Danainae)

2b. Lacking the above characters..............................................3

3a. Osmeteria present on T1......................................Papilionidae

3b. Osmeteria absent on T1.....................................................4

4a. Rolls, ties, or folds leaves when feeding.................................5

4b. Does not roll or tie leaves when feeding..................................8

5a. Leaf roller........................................................................6

5b. Leaf tier or folder...............................................................7

6a. L (prespiracular) setae on T1 bisetose.........................Pyralidae

6b. L group on T1 trisetose.........Tortricidae, Oecophoridae, Gelchiidae

7a. Leaf folder, T1 is smaller than head, giving the impression

of a "neck" region...................................................Hesperiidae

7b. Leaf tier with long, slender prolegs. Often move very rapidly

in a backwards direction when disturbed.....................Choreutidae

8a. Annulets (little wrinkles-usually 6) present on A2-A6..........Pieridae

8b. Annulets absent on A2-A6......................................................9

9a. Prolegs are modified in some way, extra prolegs are present,

or some prolegs are missing...................................................10

9b. Normal prolegs are found on segments A3-A6 and A10................14

10a. Prolegs present only on A6 and A10..........................Geometridae

10b. Prolegs present on more or fewer segments..............................11

11a. Prolegs present on A10 and 2 or 3 (but not 4) of the A3-A6 segments........................................................Noctuidae

11b. Prolegs present on A3-A6 and A10 (or more segments)...............12

12a. A10 prolegs are small and are often raised when the caterpillar is disturbed. Extra setae on prolegs A3-A6......Notodontidae

12b. Not with the above characters..................................................13

13a. Extra prolegs: A2 and A7 appear to have prolegs (with no crochets); head is usually concealed.....................Megalopygidae

13b. Extra prolegs: A1-A7 and A10 have a single median sucker that does not resemble normal prolegs. Spines are present and are often urticating......................................................Limacodidae

14a. Middorsal A8 horn present.......................................................15

14b. Middorsal A8 horn absent........................................................17

15a. Often (but not always) very large larvae (over 4 cm); annulets

present (about 6-8 per segment)....................................Sphingidae

15b. No annulets present...............................................................16

16a. Smooth rounded head, often (but not always) with many

spiny scoli, strongly biordinal crochets arranged in a

homoideous mesoseries.............................................Saturniidae

16b. Uniordinal crochets arranged in a homoideous mesoseries;

A10 prolegs are often smaller and A3-A6 prolegs are often

very hairy..............................................................Notodontidae

17a. Body dorsoventrally compressed...........................................18

17b. Body more or less cylindrical................................................19

18a. Head often much smaller than T1; A1 and A2 spiracles

are in line................................................................Lycaenidae

18b. A1 spiracle is distinctly lower than A2 spiracle..................Riodinidae

19a. Scoli with many spines present on most body segments.................20

19b. Scoli may be present or absent, but spines are not common............21

20a. Smooth rounded head. Biordinal crochets arranged

in a homoideous mesoseries........................................ Saturniidae

20b. Head angulate or bearing dorsal tubercles, horns, or

scoli......................................................................Nymphalidae

21a. Constriction behind the head gives the appearance of a

"neck"; the head is often very hairy; crochets are bi- or

triordinal and are arranged in a circle............................Hesperiidae

21b. Without the above combination of characters...............................22

22a. Head usually angulate and often much larger than T1; crochets are in a uni-,bi-, or triordinal mesoseries; stemmata are conspicuously different from one another.................Nymphalidae

22b. Without the above combination of characters....................Noctuidae

23a. Integumental spicules present.......................................Noctuidae

23b. No integumental spicules present..............................................24

24a. Single, fleshy, eversible, middorsal gland (yellow or bright

red) on A6 (sometimes on A7).....................................Lymantriidae

24b. No middorsal glands................................................................25

25a. Normal prolegs with crochets on A3-A6 and A10............................28

25b. Prolegs are modified in some way...............................................26

26a. A10 prolegs are smaller and often raised when the caterpillar

is disturbed...........................................................Notodontidae

26b. The caterpillar has extra prolegs.................................................27

27a. A2 and A7 appear to have prolegs (with

no crochets); head is usually concealed.....................Megalopygidae

27b. A1-A7 and A10 have a single median sucker that does not resemble normal prolegs. Spines are present and are often urticating.............................................................Limacodidae

28a. Heteroideous crochets............................................................30

28b. Biordinal crochets (not heteroideous) .........................................29

29a. Middorsal tapered tufts of hair; V-shaped labral notch.....Apatelodidae

29b. No middorsal tufts; U-shaped labral notch..................Lasiocampidae

30a. 4 veruccae (with many setae) above coxa on T2 and T3.............................................................................Arctiidae

30b. 3 verrucae (with many setae) above coxa on T2............................31

31a. Single V1 seta on inside of prolegs...............................Pericopidae

31b. Many secondary setae on inside of prolegs..............Ctenuchidae