Key to cysts of Stigmacoccus species studied in this paper (refers to both sizes)

1. Anal complex with a sclerotised ring lying outside openings to spiracles on abdominal segment VIII; anal complex without cone- or bollard-like spines S. garmilleri

- Anal complex without a sclerotised ring lying outside openings to spiracles on abdominal segment VIII; anal complex usually with at least one ring of cone- or bollard-like spines, similar to those near abdominal and thoracic spiracles................................................................................................................................... 2

2. Abdominal spiracles without groups of cone- or bollard-like spines around opening; anal complex with tubercle-like pores lying within a sclerotised area ........................................................ Stigmacoccus sp. A.

- Abdominal spiracles I–VII each with at least a few round, cone- or bollard-like spines associated with each spiracle; tubercle-like pores in anal complex not lying within a sclerotised area .............................. 3

3. Abdominal spiracles II–IV each with at least 50 (generally about 80 or more) rounded, mainly bollard-like spines; anal complex with a broad outer band of bollard-like spines, often wider than distance between spiracles on abdominal segment VIII ............................................................................................... S. asper

- Abdominal spiracles II–IV each with less than 20 rounded, cone- or bollard-like spines; anal complex with few cone- or bollard-like spines in outer band, never completely enclosing spiracles on abdominal segment VIII ................................................................................................................................................ 4

4. Anal complex without an outer band of cone- or bollard-like spines; each peritreme of thoracic spiracles with 2–4 rows of pores, totalling 30+ .................................................................................... S. paranaensis

- Anal complex with at least one ring of rounded, bollard-like spines in outermost band; each peritreme of thoracic spiracles with only 1–2 rows of pores, totalling less than 30 ........................................................ 5

5. Spines associated with each spiracular opening bollard-like, most about as wide as or wider than long; those associated with each thoracic spiracle present in an elongate group and about equally abundant along anterior and posterior margins of spiracles ................................................................. Stigmacoccus B

- Spines associated with each spiracular opening cone-like, mostly about twice as long as wide; those associated with each thoracic spiracle present in an elongate group, with many more spines along posterior margin than anterior margin of spiracles .............................................................................. Stigmacoccus C