Key to known developmental stages of Abrococcus cunninghamia Zheng & Wu
1(0) Legs present; antennae long and segmented................................................................ 2
- Legs absent; antennae much reduced, plate-like............................................................. 3
2(1) Antennae 7 segmented; with only 1 pair of abdominal spiracles.................................... first-instar nymph
- Antennae 10 segmented; with 8 pairs of abdominal spiracles.......................................... adult female
3(1) Anteriormost 5 pairs of abdominal spiracles with pores in atria; multilocular disc pores present on all segments............................................................................................... second-instar nymph
- Anteriormost 6 pairs of abdominal spiracles with pores in atria; terminal segment of abdomen without multilocular disc pores............................................................................... third-instar female nymph