Key to species of genus Antonina based on the morphology of first-instar nymphs

[Williams (2004) described 3 types of first-instar nymph for A. milleri, but our preliminary study based on specimens of A. milleri collected from Beijing, China, shows that type A was not present, type B is the female nymph and type C is possibly the male nymph. Considering that some Antonina species have parthenogenetic reproduction, we have here used type B as the representative for A. milleri .]

1 Trilocular pores of one size.............................................................................. 2

- Trilocular pores of two or three sizes...................................................................... 5

2 Anterior ostioles present................................................................................ 3

- Anterior ostioles absent................................................................................. 4

3 Circulus present between abdominal segments IV and V; dorsal trilocular pores not forming distinct longitudinal rows............................................................................................. A. zonata Green

- Circulus absent; dorsal trilocular pores forming 8 distinct longitudinal rows on abdominal segments...... A. australis Green

4 Dorsal trilocular pores forming 2 distinct longitudinal rows on abdominal segments...................... A. panica Hall

- Dorsal trilocular pores forming 6 distinct longitudinal rows on abdominal segments............... A. transvaalensis Brain

5 Anterior ostioles present................................................................................ 6

- Anterior ostioles absent................................................................................. 7

6 Circulus present between abdominal segments IV and V; dorsal trilocular pores forming 6 distinct longitudinal rows on abdominal segments..................................................................... A. milleri Williams

- Circulus absent; dorsal trilocular pores forming 4 distinct longitudinal rows on abdominal segments.... A. nanlingensis sp. n.

7 Apex of abdomen with 2 well-defined lateral lobes; dorsal trilocular pores fewer than 20 in number, not forming definite longi- tudinal rows on abdominal segments......................................................... A. pretiosa Ferris

- Apex of abdomen usually rounded, without well-defined lateral lobes; dorsal trilocular pores numerous (more than 20), in def- inite longitudinal rows on abdominal segments.............................................................. 8

8. Dorsal trilocular pores forming 2 distinct longitudinal rows on abdominal segments; with 1 trilocular pore associated with each anterior spiracle....................................................................... A. purpurea Signoret

- Dorsal trilocular pores forming 4 distinct longitudinal rows on abdominal segments; with 2 or 3 trilocular pores associated with each anterior spiracle............................................................................... 9

9 Circulus present between abdominal segments IV and V; with 2 trilocular pores associated with anterior spiracle...................................................................................... A. nakaharai Williams & Miller

- Circulus absent; with 3 trilocular pores associated with anterior spiracle......................... A. graminis (Maskell)