Nihonogomphus Oguma 1926

Wilson, Keith Duncan Peter & Xu, Zaifu, 2009, Gomphidae of Guangdong & Hong Kong, China (Odonata: Anisoptera) 2177, Zootaxa 2177, pp. 1-62 : 45-46

Key to Nihonogomphus Oguma 1926

Figs. 22 (a–g), 23(a–e)

1 Penile organ without posterior lobe (prepuce); antehumeral stripe absent or present as short narrow stripe without superior spot – Nihonogomphus sensu stricto............................................................................................................... 2

- Penile organ with a posterior lobe (prepuce); antehumeral stripe long with or without a superior spot, rarely with a superior spot present and stripe absent – Nihonogomphus (Lobogomphus) ............................................................... 14

2 Sides of synthorax entirely yellow................................................................................................................................ 3

- Sides of synthorax with a black suture between metepisternum and metepimeron ..................................................... 4

3 Labrum, clypeus and antefrons yellow; subgenital plate with broad, shallow notch; synthorax with broad conjoined yellow dorsal stripes; antehumeral stripe absent. Male unknown; China (Fujian)................. N (N.) gilvus Chao 1954

- Labrum black with a broad yellow transverse stripe across middle, clypeus and face of frons yellow; subgenital plate triangular-shaped without central notch or cleft; antehumeral stripe absent. Male unknown; China (Fujian)............... ............................................................................................................................ N (N.) luteolatus Chao and Liu 1990

4 Labrum black or black and yellow ............................................................................................................................... 5

- Labrum pale green; occiput grass-green, brownish at sides; synthorax background colour reddish-brown. Female unknown; Burma, Thailand. ................................................................................... N (N.) pulcherrimus (Fraser 1927)

5 Anterior hamulus very long and straight with a long, straight, narrow shaft above shoulder and a tiny hook at the apex. .............................................................................................................................................................................. 6

- Tip of anterior hamulus gradually curved to form shallow hook, which has a relatively shorter shaft above shoulder or is without a shoulder. ................................................................................................................................................ 7

6 Labrum black with a yellow transverse stripe; occiput yellow broadly bordered black; tips of superior appendages with a scoop-shaped, inner fold; posterior hamulus has a broad, humped base and prominent, claw-like tip; subgenital plate located in v-shaped recess. ( Figs. 23a–e); China (Fujian, Guangdong)............ N (N.) semanticus Chao 1954

- Labrum black; occiput yellow, finely bordered black; tip of superior appendages without scoop-shaped inner fold; posterior hamulus narrow, lacking a hump-like base with a claw-like tip; subgenital plate located in u-shaped recess; China (Guangxi, Hainan), Vietnam............................................................................. N (N.) thomassoni (Kirby 1900)

7 Anterior hamulus without a pronounced shoulder........................................................................................................ 8

- Anterior hamulus with a pronounced shoulder........................................................................................................... 10

8 Anterior hamulus without a shoulder; synthorax with broad conjoined yellow dorsal stripes; China (Zhejiang)......... ............................................................................................................................. N (N.) montanus Zhou and Wu 1992

- Shoulder of anterior hamulus is virually absent but there is a gradually curved shoulder below the curved hook; synthorax with yellow dorsal stripes not conjoined. .......................................................................................................... 9

9 Black labrum; synthorax with yellow dorsal stripes separated forming a pair of 7's, left side ‘7’ inverted; subgenital plate with a broad, shallow notch ( Figs. 22a–g); China (Fujian, Hunan)........................... N (N.) lieftincki Chao 1954

- Labrum black with a transverse yellow stripe invaded at basal centre; synthorax with very broad yellow dorsal stripes narrowly seperated centrally; Japan. ....................................................................... N (N.) viridis Oguma 1926

10 Antehumeral stripe present as very short fine stripe; anterior hamulus with a prominent shoulder at right angles to shaft of hook; China (Fujian)............................................................................................ N (N.) bequaerti Chao 1954

- Antehumeral stripe absent. ......................................................................................................................................... 11

11 Labrum entirely black; anterior hamulus with a short 90º shoulder and large scythe-like hook; distal segment of penile organ with lateral spines; inferior appendages divaricate; China (Guangxi). ...................................................... .............................................................................................................................. N (N.) huangshaenensis Chao 1999

- Labrum black with a yellow transverse stripe. ........................................................................................................... 12

12 Synthorax with broad yellow, distinctly 7-shaped dorsal stripes, left side ‘7’ inverted; anterior hamulus with a short 90º shoulder and large scythe-like hook; distal segment of penile organ without lateral spines; China (Fujian) .......... .......................................................................................................................................... N (N.) simillimus Chao 1982

- Synthorax with broad yellow dorsal stripes not distinctly 7-shaped. ......................................................................... 13

13 Anterior hamulus with an acutely pointed protruded shoulder; distal segment of penile organ without lateral spines; superior appendage ventrally downturned at tip; China (Zhejiang). ..................... N (N.) silvanus Zhou and Wu 1992

- Anterior hamulus with a thumb-like protruded shoulder; distal segment of penile organ with lateral spines; superior appendage not ventrally downturned at tip; China (Zhejiang). ................................. N (N.) chaoi Zhou and Wu 1992

14 Labrum, clypeus, and antefrons entirely yellow. ........................................................................................................ 15

- Labrum, clypeus, or antefrons with some black markings. ........................................................................................ 16

15 Antehumeral stripe complete; anterior hamulus with narrow shaft, without a shoulder and small hook; subgenital plate deep with an acutely angled (ca 45º) v-shaped notch; China (Hebei, Jiangsu, Sichuan)....................................... .............................................................................................................................. N (L.) brevipennis ( Needham 1930)

- Antehumeral stripe present with isloated superior spot; anterior hamulus hooked with a distinct, sharply pointed shoulder but not significantly protruded; subgenital plate fairly deep with an acutely angled (slightly less 90º), ushaped notch; superior appendages with small protrusions at elbows; China (Henan). ................................................. ............................................................................................................. N (L.) cultratus Chao and Wang in Chao 1990

16 Superior appendages of male with a rounded apex at elbow, when viewed both dorsally and ventrally................... 17

- Superior appendages of male with a distinct protrusion at apex of elbow, especially noticeable when viewed ventrally; antehumeral stripe absent with an isolated superior spot; subgenital plate with vulvar scales narrowly divided, sharply pointed, triangular scales; dorsum of synthorax with 7-shaped yellow stripes; China (Fujian). ....................... ...................................................................................................................................... N (L.) shaowuensis Chao 1954

17 Inferior appendages widely divaricate; superior appendages with bifid tips; subgenital plate with widely angled (equal to or slightly more than 90º) v-shaped notch; China (Qinghai), Korea, Russia. ................................................. ........................................................................................................................... N (L.) ruptus (Selys and Hagen 1858)

- Not as above; Korea.................................................................................................................. N (L.) minor Doi 1943