Pseudagrion declaratum Lieftinck, 1936

Seehausen, Malte, Kalkman, Vincent J. & Bedjanič, Matjaž, 2025, Revision of the Pseudagrion red-group occurring in Asia west of Lydekker’s line, with description of four new species (Odonata: Coenagrionidae), Zootaxa 5587 (1), pp. 1-66 : 18-20

Pseudagrion declaratum Lieftinck, 1936 stat. nov.

Figures: 26–28 (syntype ♂, labels); 83 (head ♂); 100 (pterothorax ♂); 117a, b (abdomen ♂); 134a–c (caudal appendages ♂);

155 (field photo ♂). Pseudagrion pilidorsum : Ris (1915b): 99, Fig. 20 (♂ appendages; Flores). Pseudagrion pilidorsum declaratum : Lieftinck (1936): 130, 132–134, Figs 13a, b (description ♂ ♀; ♂ appendages; key;

Lombok, Sumbawa, Sumba , Flores);— Lieftinck (1953): 156–157 (Alor, Sawu);— Kosterin (2014): 16, 21, Figs 9, 13, 20

(Bali, scarce; Lombok, abbundant; photos alive & habitat). Pseudagrion pilidorsum deflexum : Irawan & Rahadi (2018): 87 ( Sumba ).

Name-bearing type specimens examined (1♂, 1♀)

1♂, 1♀ syntype, iv.1896, Sapit , Lombok, Indonesia, 2000 m a.s.l., H. Fruhstorfer leg., ZMH ( Figs 26–28) .

Lieftinck (1971: 83) designated a lectotype male with the data » Labuan Badjo , 100 m, xi.1937, J.K. de Jong «. However, the syntype series contains only specimens from this locality and collector which were collected during » x.–xi.1929 «. Furthermore the respective envelope held at RMNH (No. JvT no. 2813) contains two males and a female. Thus the designation by Lieftinck (1971) is invalid because he did not choose a specimen from the syntype series, and he even did not unambiguously select a particular specimen ( ICZN 1999: 74.2 and 74.5). We do not consider it necessary to designate a lectotype, thus we propose to keep them as syntypes.

Other specimens examined (29♂♂, 5♀♀)

Indonesia, Flores Island: 2♂♂, xi.1896, South Flores, R. Martin leg., SMF , no. 13973–13974;— 1♂, 28.ix1908, North Flores, Rioeng Papang, river Alo Wai, v.d. S. leg., RMNH ;— 2♂♂, 1♀, vi.1937, Labuan Badjo , West Flores, J.K. de Jong leg., RMNH , JvT no. 2813.

Indonesia, Lombok Island: 7♂♂, 1♀, iv.1896, Sapit, 2000 m a.s.l., H. Fruhstorfer leg., SMF , no. 2314–2317, 13763–13766;— 4♂♂, v.1896, Ekas , H. Fruhstorfer leg., SMF , no. 13761–13762, 13768–13769;— 1♂, without particular locality, SMF , no. 13767;— 1♂, 21.iv.1927, Selong, Sunda-Expedition Rensch, SMF , no. 1Ris01;— 7♂♂, 2♀♀, 18.ii.1993, Lendang Bajur, J. Belle leg., RMNH .

Indonesia, Sumba Island : 2♂♂, xii.2015, without particular locality, MWNH .

Indonesia, Sumbawa Island: 1♂, 29.v.1927, Dompu, Sunda-Expedition Rensch, SMF, no. 1Ris03 .

Indonesia, Java Island: 1♂, August, without particular locality, NHMUK, no. 012495866 ;— 1♀, vii.1918, Bagor, Dr W. Röpke leg., SMF, no. 13947 .

Characterization of male

Head ( Figs 26, 83, 155): Labrum, clypeus, antefrons and postfrons yellow-orange; colour of postfrons distinctly separated from red vertex around level of lateral ocelli; postocular spots red, separated by a very thin black line from postfrons; rear of head black, but broadly yellow-orange along the eye margins; base and scape of antennae yellow, following segments brownish; eyes when alive reddish, anteriorly washed-out yellow-orange.

Thorax ( Figs 26, 28, 100, 155): Anterior, middle, and posterior lobe of pronotum dorsally red; middle pronotal lobe with a black patch on each side dorsolaterally, along the margin between anterior and middle lobe; sutures of middle lobe black, posterior margin of middle lobe broadly black; apical edge of posterior lobe convex. Pterothorax red with a thin black middorsal carina; a black stripe at posterior quarter of humeral suture and metapleural suture, both expanded in the middle; ventrally pale, may be covered with whitish pruinosity. Legs pale reddish; femora may have a blackish stripe outside, narrowing proximally; tibiae blackish along spines; spines black.

Abdomen ( Figs 26, 28, 117a, b, 155): S1 red; S2 red, often with a blackish marking at the posterior quarter, which may be connected by a blackish middorsal stripe with black posterior margin; S3–8 dorsally black, laterally pale whitish-yellow; S9 red with posterior edge black; S10 red with black dorsal “x”-like marking, variable in shape.

Caudal appendages ( Figs 134a–c): Cercus laterally washed-out darkish red, its edges black; slightly shorter than S10; in lateral view cercus subrectangular with open inter-lobe notch low on apex; in dorsal view cercus appearing narrow, apex of the superior lobe narrowly rounded and hooked inwards; a blunt interior projection (appearing subtriangular in dorsolateral view) is present at ca. the middle of the superior lobe; a tiny subbasal interior tooth-like projection on the inferior lobe at ca. the basal third; paraproct pale yellow-ochre, about half as long as cercus; in lateral view subtriangular and tapered with rounded apex; in dorsal view broadly rounded, concave bowl-like, with black tooth at medial edge.

Characterization of female

Head: As in male but red replaced by orange-ochre.

Thorax: Pronotum and pterothorax as in male but red replaced by orange-ochre; posterior lobe of pronotum with two horns directed towards the head, almost reaching the centre of the middle lobe; pterothorax may be tinted greenish antehumerally.

Abdomen: S1 orange-ochre; S2 orange-ochre, with black marking middorsally; S3–8 as in male; S9–10 laterally orange-ochre, dorsally with black markings variable in shape. Cercus washed-out dark brownish, as long as half of S10; paraproct brownish, in lateral view rounded; ovipositor pale yellowish, its apex not reaching to posterior end of S10; two brownish styles reaching beyond S10; inferior edge of ovipositor bearing several very small teeth.

Wings of both sexes with 11.5–13.5 px in forewing, and 10–12.5 px in hindwing.

Measurements of both sexes (mm): Total length (with appendages) 38.5–47.0; abdomen length (without appendages) 30.4–37.9; hindwing 20.6–25.0; forewing 22.0–26.5; Pt in forewing 0.7–0.9; male cercus 0.6–0.8.

Diagnosis

This species differs from almost all other species of the Pseudagrion red-group by the largely yellow-red head, bearing just a very thin black line around large red postocular spots ( Figs 26, 83, 155). This colour pattern is shared only by P. deflexum ( Figs 29, 84), but living males of this species have the anterior half of the eyes distinctly yellow ( Figs 157, 158). The laterally subrectangular male appendages of P. declaratum ( Fig. 134a) separate this species from several congeners as well, especially from the similarly coloured P. deflexum , in which the cercus is distinctly arched in lateral view ( Figs 135a, 159). The male caudal appendages of P. obscurum and P. simalurum ( Figs 140a–c, 141a–c) as well as of P. igneum and P. nigrihumerale ( Figs 138a–c, 139a–c) have superficial similarities with those of P. declaratum , but these species (except for P. nigrihumerale ) are separated by having S1–2 dorsally black ( Figs 121a, b, 123a, b, 124a, b), black colouration around the postocular spots ( Figs 87, 88, 89, 90), and regarding P. nigrihumerale by having a black humeral stripe ( Fig. 105).

Distribution

This species is distributed from Java towards the Lesser Sunda Islands Bali, Lombok, Sumbawa, Flores, Sumba, Sawu , and reaching Alor ( Fig. 2).