1(0) Legs absent; antennae each much reduced, plate-like......................................................... 2

- Legs present; antennae each long and segmented............................................................ 5

2(1) Body shape tadpole-like; vulva present........................................................... adult female

- Body oval or oblong; vulva absent........................................................................ 3

3(2) Body elongate oval, more than twice as long as wide..................................... second-instar male nymph

- Body slightly pyriform, less than twice as long as wide....................................................... 4

4(3) Multilocular pores forming a single transverse row between spiracles on abdominal segments IV and V............................................................................................... second-instar female nymph

- Multilocular pores forming 2 or 3 transverse rows between spiracles on abdominal segments IV and V................................................................................................. third-instar female nymph

5(1) With wings or wing buds; antennae each 10-segmented....................................................... 6

- Without wings or wing buds; antennae each with 7 or 9 segments............................................... 7

6(5) Wings fully developed; legs each with a claw........................................................ adult male

- Wings only in bud state; legs each without a claw......................................................... pupa

7(5) Antennae each 7-segmented; mouthparts developed............................................ first-instar nymph

- Antennae each 9-segmented; mouthparts absent or much reduced............................ third-instar male nymph