Prosopistoma

Shi, Weifang & Tong, Xiaoli, 2013, A new species of Prosopistoma (Ephemeroptera: Prosopistomatidae) from China with a key to Oriental species, Zootaxa 3718 (1), pp. 89-96 : 95

Key to known mature nymphs of Oriental Prosopistoma species

1. Posterolateral projections on abdominal segments VII to IX broad and truncated.................................... 2

- Posterolateral projections on abdominal segments VII to IX apex pointed........................................ 3

2 Base of inner canine in mandible with 7 long serrated bristles; apex of ventral margin of fore-tibia with 2–4 serrated spines [New Guinea, Solomon Islands]........................................................... P. sedlaceki Peters

- Base of inner canine in mandible with 2–3 long bristles; apex of ventral margin of fore-tibia with 3–4 serrated spines [Indone- sia (Borneo)]............................................................... P. o l y mpu s Sartori & Gattolliat

3 Mesonotum uniformly reddish-brown except for 2 pairs of dark brown circle spots; base of inner canine with 3 long bristles; apex of ventral margin of fore-tibiae with 11 serrated spines [ China (Yunnan)]............... P. unicolor Zhou & Zheng

- Mesonotum bicolored with irregular yellow and brown color pattern............................................ 4

4 Base of inner canine in mandible with more than 3 long bristles................................................. 5

- Base of inner canine in mandible with 3 long bristles......................................................... 7

5 Apex of ventral margin of fore-tibiae with more than 3 spines; base of inner canine in mandible with less than 10 long bristles................................................................................................... 6

- Apex of ventral margin of fore-tibiae with only 2 spines; base of inner canine in mandible with 12–13 long bristles; inner canine much shorter and slimmer than outer canine [ Sri Lanka].................................. P. lieftincki Peters

6 Antennae with 6 segments, segment III shorter than the combined length of segments IV–VI; apex of ventral margin of fore- tibia with 4–6 serrated spines [ Philippines].................................................... P. boreus Peters

- Antennae with 5 segments, segment III much longer than the combined length of segments IV–V; apex of ventral margin of fore-tibia with 6–8 serrated spines [ China (Guangdong, Hong Kong); Thailand] P. sinense Tong & Dudgeon

7 Antennal segment III much longer than the combined length of segments IV–V.................................... 8

- Antennal segment III not exceeding the combined length of segments IV–VI..................................... 9

8 Antennae 5-segmented; apex of ventral margin of fore-tibia with 6 spines [ India]..................... P. indicum Peters

- Antennae 6-segmented; apex of ventral margin of fore-tibia with 10–11 serrated spines [ China (Guangxi, Hainan)]............................................................................................... P. ocellatum sp. n.

9 Apex of ventral margin of fore-tibiae with more than 3 spines; base of inner canine with 3 long bristles................ 10

- Apex of ventral margin of fore-tibiae with only 3 spines; base of inner canine with 6 long bristles [ China (Yunnan)]...................................................................................... P. trispinum Zhou & Zheng

10 Apex of ventral margin of fore-tibiae with 8 spines.......................................................... 11

- Apex of ventral margin of fore-tibiae with at most 6 spines.................................................... 12

11 Apical segment of maxillary palpus longer than 1/2 length of segment II; mesonotum anteriorly and posteriorly with two large, transversal and not connected dark-brown bands which separated by a large pale band [ Vietnam]................................................................................................. P. funanense Soldán & Braasch

- Apical segment of maxillary palpus shorter than 1/2 length of segment II; mesonotum with five dark-brown patches which connected by brown narrow stripes [Sunda Islands].......................................... P. wouterae Lieftinck

12 Antennal segment III equal in length to the combined of segments IV–VI; mesonotum without any pale spots in anterior dark- brown band [ Philippines]................................................................ P. palawana Peters

- Antennal segment III clearly shorter than the combined length of segments IV–VI; mesonotum with many pale spots in ante- rior dark-brown band [ China (Hunan); Vietnam; Thailand]......................... P. annamense Soldán & Braasch