Pseudagrion pruinosum elongatum Needham, 1930

Pseudagrion pruinosum elongatum Needham, 1930 View in CoL stat. nov.

Figures: 73–75 (holotype ♂, labels); 94 (head ♂); 111 (pterothorax ♂); 128a, b (abdomen ♂); 145a–c (caudal appendages ♂); 174–178 (field photos ♂).

Pseudagrion elongatum View in CoL : Needham (1930): 261–262 (description ♂; China);— Asahina (1988): 2–3, Figs 1–4 (♂ appendages; considered a jun. syn. of Pseudagrion pruinosum fraseri Schmidt, 1934 View in CoL ).

Pseudagrion pruinosum View in CoL : Ris (1915b): 97 –98, Fig. 18 (Malaka [ Malaysia]);— Fraser (1927): 91 ( Thailand, Myanmar);— Fraser (1933): 305 –306, Fig. 128 (description ♂ ♀; ♂ appendages);— Asahina (1969): 2 ( Vietnam);— Asahina (1982): 465 ( Thailand; intermediate between pruinosum View in CoL and ranauense Schmidt, 1934, rather come to fraseri Schmidt, 1934);— Asahina (1997): 19, Fig. 6 ( Vietnam; ♂ appendages);— Murphy (1997): 338 ( Singapore; rare);— Hämäläinen & Pinratana (1999): 50 ( Thailand; map);— Cuong & Hoa (2007): 54 ( Vietnam; map);— Roland et al. (2011): 12, Fig. 13 (1 st record Cambodia; photo ♂);— Payra et al. (2018): 26 –30 (1 st record mainland India).

Pseudagrion pruinosum fraseri View in CoL : Wilson (1999): 30 (Guangdong, China);— Wilson & Reels (2001): 149, 152 (Hainan, China);— Tam (2003): 8 (1 st record Hong Kong; misspelled as P. p. frasei);— Zhang (2011): 8 (Guizhou, China; common);— Yokoi & Souphanthong (2014): 14 (Lao PDR);— Reels (2019): 9 ( Hong Kong, China; scattered).

Pseudagrion pruinosum ranauense View in CoL : Kemp & Kemp (1989): 39 (Perak, Malaysia).

Name-bearing type specimen examined (1♂)

♂ holotype, [26.viii., Lin-yung-hsien], China, no. 54, C.U. No. 962.1, CUIC, no. 00082418 ( Figs 73–75) .

Other specimens examined (8♂♂, 2♀♀)

Malaysia: 1♂, Malacca, Grubauer leg., ex. Museum München, SMF , no. 13937;— 1♂, 11.iii.1999, Kuala Juram, Taman Nagara, Merapoh, Pahang, 4.6387°N, 102.1224°E, T. Trilar & K. Prosenc leg., MB GoogleMaps .

Myanmar: 1♂, 20.viii.1977, Maymyo [Pyin U Lwin], 1200 m, G. v. Rosen leg., ZSM, no. GvRosen 5330 .

Thailand: 1♂, Bangkok, ex. Coll. Williamson, ded. F.C. Fraser, SMF, no. 13936 ;— 1♂, 6.ix.1973, Mae Sa, north of Chieng Mai , 500 m, G. v. Rosen leg., ZSM, no. GvRosen 3255 ;— 1♂, 1♀, 9.–10.i.1993, Huai To waterfall,

Khao Phanom Bencha, Krabi, M. Hämäläinen leg., RMNH, no. 1658929, 1658930;— 1♂, 6.–7.iv.1998, Klongthom, Khao Prabangkram WS, Krabi, M. Hämäläinen leg., RMNH, no. 1658931 ;— 1♂, 1♀, 7.iv.2001, Pilock, small stream near Pilock Basin , Kanchanaburi, 650 m a.s.l., M. Hämäläinen leg., RMNH, no. 1658927, 1658928 .

Characterization of male

Head ( Figs 74, 94): Labrum and anteclypeus yellow-orange; postclypeus either black, or with three blackish patches, one in centre and others dorsolaterally; antefrons and postfrons reddish, laterally orange-reddish, when immature morely yellowish-orange; colour of postfrons sharply separated from black vertex around level of lateral ocelli; postocular spots reddish, but may become indistinct dark and hardly visible in older individuals, when immature morely yellowish-orange; rear of head black, covered with bluish pruinosity in older individuals, with pale yellow-orange along the eye margins; base of antennae orange-reddish; scape of antennae anteriorly orange-reddish, but posteriorly darkish; following segments brownish.

Thorax ( Figs 73, 111, 174–178): Anterior, middle and posterior lobe of pronotum in mature males covered with bluish pruinosity, but when immature probably similar to the female; apical edge of posterior lobe convex. Pterothorax in mature males covered with bluish pruinosity, with obscurely blackish dorsum to varying degrees, but when immature pterothorax orange, with at least middorsal carina and humeral suture black ( Fig. 174), but the black colour may extend to a black middorsal stripe, and a black humeral stripe of varying degrees, and also antehumeral area may become obscurely blackish in immature ( Fig. 175); a blackish stripe or a patch along posterior third of interpleural suture may be present; metapleural suture may have a black stripe, or a black patch at posterior third; venter washed-out pale brownish. Legs pale; femora with blackish stripe outside, but may become almost completely obscurely blackish and covered with bluish pruinosity with maturity; tibiae blackish along spines; spines black.

Abdomen ( Figs 73, 128a, b, 174–178): S1–2 at least with black patches dorsally, but dorsum may be completely black, both segments covered with bluish pruinosity in mature individuals ( Figs 73, 128a, b, 176–178); laterally basic colouration when immature yellowish-orange ( Fig. 174); S 3–8 in all ages dorsally black, laterally yellowish-orange to almost washed-out darkish; S8–10 covered with bluish pruinosity in mature individuals ( Figs 111, 176, 178); in immature S9–10 dorsally with black markings, variable in exact shape ( Figs 174, 175).

Caudal appendages ( Figs 145a–c): Cercus laterally blackish, slightly shorter than S10; in lateral view cercus subrectangular, but with upper margin gently arched, apex with inter-lobe notch in lower quarter and apex of inferior lobe slightly projecting nipple-like; in dorsal view the cercus appearing narrow, and smoothly arched; apex of the superior lobe rounded and turned inwards (more markedly so in dorsolateral view); a rounded subtriangular projection is situated at around two-thirds of the length of the superior lobe of the cercus; inferior lobe of the cercus interiorly with a ridge running to apex visible in dorsolateral view, starting from a small subbasal bulg-like projection situated around the middle of the height of the cercus, this bulg-like projection bearing a sharp proximal edge and looks like a small tooth in dorsal view; paraproct pale orange-ochre; slightly longer than half of the cercus; in lateral view subtriangular and tapered with rounded apex; in dorsal view broadly rounded, concave bowl-like; medial edge blackish tubercular.

Characterization of female

Head: Almost as the male, but yellow-ochre instead of reddish; a blackish spot in centre of labium may be present; postclypeus with three blackish spots, one in centre at margin towards antefrons, and one each dorsolateral; occipital bar more distinct than in the male.

Thorax: Anterior lobe of pronotum yellowish-ochre, this colour expanding in the centre towards middle lobe, its anterior margin black; middle pronotal lobe black, with a centrally divided yellowish-ochre patch in the middle, and on either side an yellowish-ochre spot dorsolaterally; propleuron black above, yellowish-ochre below and to rear; posterior lobe of pronotum yellowish-ochre, bearing two horns directed towards head, approximately reaching the centre of the middle lobe. Pterothorax orange-ochre, but in life antehumeral area, and lateral may be greenish, with orange-ochre restricted to humeral area and mid of dorsum; middorsal carina black; humeral suture and metapleural suture each with a black patch situated at the posterior quarter; venter pale. Legs as in the male.

Abdomen: S1–10 dorsally black, laterally pale yellowish. Cercus washed-out dark, but pale in younger individuals; as long as half of S10; paraproct pale ochre, in lateral view rounded; ovipositor pale yellowish-ochre, not reaching to posterior margin of S10; two brownish styles reaching beyond S10; inferior edge of ovipositor bearing several very small teeth.

Wings of both sexes with 12.5–15.5 ax in forewing, and 10.5–12.5 px in hindwing.

Measurements of both sexes (mm): Total length (with appendages) 37.5–44.5; abdomen length (without appendages) 30.4–36.5; hindwing 21.3–25.6; forewing 22.5–27.1; Pt in forewing 0.7–1.0; male cercus 0.5–0.7.

Diagnosis

This subspecies is, like the nominate subspecies, easily separated from all congeners by its bluish pruinosity at the pterothorax and abdomen of mature males, leaving no reddish colour ( Figs 73, 111, 128a, b, 176–178). Differences to distinguish mature males of the nominate subspecies and P. p. elongatum are summarised in table 3. Additionally mature males of P. p. elongatum generally have an obscurely blackish dorsum of the pterothorax variable in extent ( Figs 176–178), but this may be presented to a lesser degree in some individuals of P. p. pruinosum as well ( Fig. 172). The tendency of P. p. elongatum to have S8 of the abdomen fully covered with pruinosity ( Figs 128a, b, 176, 178), whereas only the posterior half is covered in P. p. pruinosum ( Figs 127a, b, 171), is not recommended for separation because it could be variable. Also the pale hind margin of the rear of the head in P. p. pruinosum ( Fig. 93) compared to a completely blackish hind margin in P. p. elongatum ( Fig. 94) is not recommended for separation, because at least in Sumatra both variations occur.

Distribution

This subspecies is found on mainland Asia, and is known from northeast India, Myanmar, Thailand, Laos, Cambodia, Vietnam, and southern China at least as far as Hong Kong. The southernmost populations are found in Peninsular Malaysia, and Singapore ( Fig. 1). The exact range, especially within Myanmar and Laos, needs to be studied.