Dragonfly ID questions, China 2006 (1 Viewer)

[Sangahyando]

These are some old pictures from August 2006 I've never gotten around to identifying; also, I'm not all that confident in my dragonfly ID skills.
All images cropped, for the usual reasons. As usual, help would be much appreciated.

#1 is from Taihuai, northern Shanxi; Cordulegaster sp.?
#2 is from Chengdu, Sichuan; Orthretum sp.?
#3 is from Yangshuo, northern Guangxi; bit of a long shot
#4 also from Yangshuo; Gomphidae sp.?

 

[creaturesnapper]

No3 is probably —-Orthetrum pruinosum

 

[Sangahyando]

No3 is probably —-Orthetrum pruinosum

Thanks, that looks like a sensible suggestion.

 

[birdwatcher667]

Your No.4 image (Gomphidae) has the features of an Ictinogomphus. These species generally have a pair of flanges on the underside/ventral side of the eighth abdomen segment S8. It is probably Ictinogomphus pertinax, based in part on being the only one of the Ictinogomphus species found in China that is listed on the recent Guangxi survey's checklist for the region (see third link below). The most similar other species Ictinogomphus rapax might possibly also be found in Guangxi but it visually differs notably in that it has abdomen segment S8 yellow on the dorsal (back) side - whereas S8 dorsal side is black in your photo . A third Ictinogomphus species found in SW China, Ictinogomphus decoratus, may also be visually excluded on the grounds that it has less complex yellow markings on the side of the thorax than in your photo. https://www.odonata.org.uk/wp-content/uploads/2020/03/Ictinogomphus-comparison-960w.jpg . In Hong Kong Ictinogomphus pertinax is given the name 'Common Flangetail' . See Common Flangetail | HKdragonfly . https://www.researchgate.net/public...ng_Autonomous_Region_China_part_II_Anisoptera

 

[birdwatcher667]

Your No.1 image Cordulegaster looks to be the Chinese endemic Cordulegaster (or Neallogaster) pekinensis as shown in the Figure 43 of Van Pelt's Notes ; Notes on some Chinese and Himalayan Cordulegastridae (Insecta: Odonata: Anisoptera) | Semantic Scholar . There isn't much other reference to this Chinese endemic dragonfly on-line but for a golden-ringed dragonfly it unusually has just pairs of golden lunules rather than complete golden rings around the abdomen and has a very distinctive five golden spot-marking arrangement on the second abdomen segment S2. It is also practically identical to a photo on Flickr labelled as 'Neallogaster pekinensis' from a Chinese forestry graduate who seems knowledgeable on the local insect fauna (see

https://flic.kr/p/PfSMsg

).

 

[birdwatcher667]

Your No.2 image Orthetrum looks to be Orthetrum melania. They are listed for Guangxi Region and Sichuan Region. The blue-veined dark bases of the wings combined with the black S8-10, otherwise all blue thorax and abdomen, green eyes, black pterostigma and black costa and smoky dark brown wing tips looks to be distinctive of that species. .In Hong Kong they are known as Greater Blue Marsh Skimmer (- there is probably no English name for it in China). See Greater Blue Marsh Skimmer | HKdragonfly

 

[Sangahyando]

Thanks, appreciate these pointers a lot.