Sieboldius (Pseudohagenius) deflexus ( Chao 1955 )

Wilson, Keith Duncan Peter & Xu, Zaifu, 2009, Gomphidae of Guangdong & Hong Kong, China (Odonata: Anisoptera) 2177, Zootaxa 2177, pp. 1-62 : 52-56

Sieboldius (Pseudohagenius) deflexus ( Chao 1955)

Figs. 27 (a–j), 28(a–h)

Sieboldius sp. ? – Needham (1930: 31–32, pl. 4, figs 3 & 3ª, larvae, Zhejiang); Lieftinck (1932: 106–107, Fig. 4, larvae, Zhejiang).

Hagenius (Hagenius) deflexus Chao 1955 : Chao (1955: 73, 76–77, figs 554–555, 566–573, Fujian); Steinmann (1997: 217).

Sieboldius deflexus ( Chao 1955) : Asahina (1972: 2, figs 3–4, ♂, Taiwan); Asahina (1977: 37, ♂, Taiwan); Matsuki (1978: 138, 140, 153, fig. 15, larvae, Taiwan); Lieftinck et al. (1984: 30, Taiwan); Wang (2000: 184, photo ♂, Taiwan); Hua (2000: 12, Fujian, Taiwan & Zhejiang); Fellowes et al. (2003a: 37, Guangdong: Dadingshan, Nanling); Wilson (2005: 141–143, figs 23a–c, ♀, Guangxi).

Sieboldius (Pseudohagenius) deflexus ( Chao 1955) : Carle (1986: 285); Chao (1990: 399–402, figs 1–18, Fujian); Zhang (1999: 254–255, figs 24.83a–h, Fujian, Taiwan & Zhejiang).

Hagenius (Pseudohagenius) deflexus ( Chao 1955) : Bridges (1994: VIII.28).

Specimens: 1 ♀, 30 vi 2000, Dadingshan , Nanling, Guangdong, coll. KW; 1 exuviae, Bride's Pool, Hong Kong, 17 v 2007, coll. SS .

Measurements (mm): ♀, abd. + app. 64.0, hw 60.0, larvae, length 38.0, head width 9.0, width 22.0.

Remarks: The female specimen of S. deflexus from Guangxi illustrated in Wilson (2005) has the same colour pattern as the Guangdong female but the v-shaped angle between the vulvar scales of the postgenital plate appears to be more acute. On careful, side-by-side comparison of the two specimens, the apparent difference in angle is an artifact caused by the degree of lateral compression. The postgenital plate of the Guangxi specimen ( Fig. 27f) is laterally compressed, with vulvar scales curved slightly inwards, whereas the postgenital plate of the Guangdong specimen ( Fig. 27e) is almost flat, which has the effect of making its notch appear shallower in angle. The Guangxi specimen is a mature adult with a rounded abdomen and there is an egg lodged beneath its vulvar scales. The Guangdong specimen is a less mature specimen with a laterally compressed caudal abdomen in contrast to its almost flat postgenital plate. The conical structures above the lateral ocelli are slightly more prominent in the Guangxi specimen. Both female specimens possess cerci which are very short, being equal to or slightly shorter than S10. In comparison the cerci of S. alexanderi and Sieboldius maai from Fujian & Zhejiang, are 1.5–2 times the length of C10 (cf Fig. 27i).

Needham (1930) described Sieboldius herculeus from a single female collected by C.R. Kellogg in Fujian. Hui (2000) also records S. herculeus from Guangdong but no details of the record are provided. As pointed out by Asahina (1972) there is a possibility that Sieboldius deflexus is a junior synonym of S. herculeus . But, given the pale colouration and more extensive yellow colour pattern on the S. herculeus abdomen, it may indeed represent a distinct species. Needham's (1930) description is compared, below in Table 5, with a corresponding description of S. deflexus from Guangdong. Both S. herculeus and S. deflexus have short cerci and have a transverse yellow crest across the postfrons, which does not extend onto the antefrons and is contricted or narrowly divided at the centre ( Figs. 27a–b). In Sieboldius japponicus Selys , the nominate subgenus type species known from Borneo, Burma, Sumatra, P. Malaysia and Thailand, the entire postfrons is yellowish-white and in S. alexanderi and S. albardae the frons is covered by a broad yellow stripe across the entire dorsum.

Carle (1986) erected the subgenus Pseudohagenius to receive Sieboldius possessing pterostigmata with brace veins and males with superior appendages lacking sharply pointed processes, directed posteriorly. Sieboldius deflexus is the only species within the Pseudohagenius subgenus although the affiliation of S. herculeus , with unknown male, at subgeneric level is not known, but is probably also within this subgenus. The tips of male Pseudohagenius superior appendages appear rounded when viewed dorsally ( Figs. 28b–c). All other Chinese Sieboldius belong to the nominate subgenus. The larva of Sieboldius deflexus collected from Zhejiang has been illustrated, as Sieboldius sp. , by Needham (1930), and Matsuki (1978) has also illustrated S. deflexus larvae collected from Taiwan. The S. deflexus submentum possesses 12–13 rectangularshaped teeth, whereas the submentum in S. maai , figured by Chao (1990), has 18 teeth and S. japponicus , figured Lieftinck (1932), also has 18 teeth. Sieboldius albardae exuviae collected from Honshu, Japan has ca 18 teeth, but the exuviae is significantly smaller; length 31.5 mm, head width 8.0 mm, width 17.0 mm. Chao (1990) also figured a Sieboldius sp. larvae collected from Fujian, length 37.0 mm, head width 8.5 mm, width 20.5 mm, with a submentum bearing 14 teeth, which may prove to be the larva of S. alexanderi . The S. deflexus exuviae, illustrated in Figs. 28d–h, collected from a hillstream at Brides Pool, Hong Kong by Samson So, is identical to Matsuki's (1978) illustrations of S. deflexus from Taiwan and represents a new species record for Hong Kong. Carle’s subgenera are based on rather tenuous characters, representing minor morphological differences, which given the sparcity of species within the genus appears to be unwarranted.

Distribution: China (Fujian, Guangdong, Hong Kong, Taiwan & Zhejiang).

description of deflexus from Guangdong.

Sieboldius herculeus Corresponding Sieboldius deflexus

Head Frons uniform brown with yellow superior cross band Front of frons uniformly blackish-brown and dorsum that narrows towards the ends and narrowly divided in with yellow band that narrows towards the ends and the middle. almost divided at the middle.

Occiput Brown, nearly straight, margin a little depressed each Blackish-brown, with a low central hump and lateral side and densely fringed with hairs. depressions and margin densely fringed with short black hairs

Synthorax, Front of thorax brown with yellow carina and a yellow Ditto dorsum cross band on the collar and a pair narrow yellow antehumeral stripes that do not reach the collar but are dilated to reach outer angle of the crest at the upper ends.

Synthorax, Sides with two broad oblique bands with alternating Ditto - with small, isolated yellow superior spot on the lateral black and yellow. The foremost black band is the metepisternum humeral band, the other centers on the second lateral suture, and is wide enough to overspread the spiracle; the yellow bands on either side of it are straight-edged.

Legs Brown, hind femur 18 mm Blackish-brown, hind femur 18 mm

Abdomen Mostly brown, the basal middorsal pale stripe does not Blackish-brown, middorsal yellow stripe not extending to reach the apex of the second segment, nor does the distal margin of S2. Dorsum of S1 with tuft of long black yellow of the sides. Dorsum of S1 bears tufts of long hairs. Tuft of long black hairs just above yellow spot on black hairs. There are tufts of black hair on the sides of S1 and opposite to these hairs a further tuft of long black the first segment superiorly and on the opposite adjacent hairs on metathoracic pleural suture at the base of the convexity of the metathorax. Segments 3–8 have paler hindwing. S3–8 have yellow spots at their basal lateral half rings occupying the basal third of the segment; their margins with the largest spot on S8 occupying basal third lateral margins also are obscurely yellow. Segments 9–10 of the segment. S4–S7 yellow lateral spots occupy no brown. more than basal fifth of segments. S9–10 blackish-brown.

Caudal Very short appendages (shorter than S10) are blunt at the Very short appendages (shorter or equal to S10), which appendages ends with a blackish inferior end tooth. are blunt at the ends with a blackish inferior end tooth. ( Figs. 27e–g)

Subenital Plate 5, fig. 3 (vulvar scales shallow and broadly Fig. 27e–f. Vulvar scales shallow and broadly divergent.

plate divergent).