Heliaeschna bartelsi, M.A. Lieftinck, 1940

M. A. Lieftinck, 1940, Descriptions and records of South-East Asiatic Odonata (II), Treubia 17 (4), pp. 337-392 : 386-390

Heliaeschna bartelsi , sp. n.

1909. MARTIN, Cat. Coll. SELYS, fasc. 20, Aeschnines, p. 161 162, fig. 162 (apps. ♂). — ♂♀ Borneo; " Cooktown " (error). ( simplicia ).

1911. MARTIN, Genera Insect. WYTSMAN, fasc. 115, p. 26, pl. 6 fig. 1 (col. fig. ♂), 1a-b (apps. ♂) ( simplicia ).

Material studied: — 1 ♂ (ad), labelled: “ Borneo, W.K. ” (Selys, yellow), “ Heliaeschna simplicia Karsch ♂ Borneo ” ( Selys , white) ; 1 ♂ (juv., apps. lack- ing), " Borneo W.K." ; 2 ♀, Borneo, W.K.”, one identified with Heliaeschna simplicia Karsch ♀ Borneo ” (SELYS, white); all in the Brussels Museum . —- 2 ♂ (ad.), S. Sumatra, Lampong Res.: Menggala , Terbanggihilir , low country, Aug. 16 20, 1936, MAX BARTELS leg., in the Buitenzorg Museum. - 4 ♂, 4 ♀ (juv-ad), W Borneo, Singkawang distr., near Bakoean , Febr. 18, 1932 and Jan. 22, 1933 (1 ♂, 2 ♀ juv.); Jan. 22 and April 9 - 10, 1934 (3 ♂, 2 ♀ ad.), L. Coomans DE Ruiter leg., in the Buitenzorg Museum .

ı

Holotype ♂ and allotype ♀: W Borneo, Bakoean, April 9- 10, 1934.

Male (ad.). — Mouth-parts ochraceous-orange, usually discoloured to cinnamon; labrum in one example with distinct greenish intermingling. Clypeus and frons ecru-olive (RIDGWAY), fading to olive-ocher laterally and over the sutures. Frontal ridge acute, obtuse-angulate and ˄-shaped in dorsal view, the ridge itself pale-coloured. Dorsal surface of frons and vertex finely rugosely punctured, brownish-olive in colour. Occipital triangle dark brown. Antennae brown. Eyes dark greenish-blue. Rear of the head cinnamon-buff.

Synthorax short and small. Dorsum, to almost as far laterally as the humeral suture, lumiere blue (RIDGWAY), including the ante-alar triangles; this colour changing into a delicate turtle- or malachite green, laterally. Dorsum and sides unmarked save for the mid-dorsal carina, the borders of the ante-alar triangles, and the upper margin of the pleurae, which are brown. Under surfaces and coxae pale brownish or flesh-coloured; metasternum slightly pruinose. Nota and axillaries lumière blue. Legs dark purplish-brown to almost black; inner surfaces of femora, distal third of tibiae, and all tarsi, diffusely cinnamon-rufous.

1) R. MARTIN, Cat. Coll. SELYS, fasc. 19, 1909, Aeschnines, p. 113 fig. 106 (♂), p. 114 fig. 107 (♀, sub perampla).

M. A. LIEFTINCKZ Descriptions and TCCOITÍS of S. E. Asiatic Odonata . 387

Wings very long, with the basal half rather narrow, the apical part gradually diminishing in width towards the apices, which are evenly and bluntly rounded; greatest breadth of hind wing before the nodus. Membrane strongly tinted throughout, usually deeply and evenly enfumed, save for the extreme bases, which are hyaline. Venation moderately dense, brown. Primary antenodals the first and ninth tenth. A basal postcostal nervure invariably present in or all wings. Arc situated mid-way between the two primary antenodals. t elongate, made up of 6 - 7 cells, distal side sinuous; basal angle situated distal to level of Arc for a distance about half as long as proximal side. ht traversed by 4 - 7 cross-nerves in fore wing, 5 - 6 in the hind (4.5 in fore wing of type). Basal Part of hind wing rather narrow, base obtuse-angulate; tornus in line with distal side of anal triangle obtuse-angulate. Anal triangle three-celled, its costal side exceptionally long, scarcely less than three-fourths as long as distal side. Membranula vestigial, whitish. Anal loop oval, made up of 8 - 10 cells. Antenodals 22-26/18-20, postnodals 13-15/15-18 (13.23 23.14/18.19.19.15 in the holotype). Cubital space (including ti) traversed by 10 - 1.1 cross-nerves in fore wing, 8 - 9 in the hind; m with 5 - 7 cross-nerves in fore wing, 4 - 6 in the hind wing (7.5/5.6 in the type). Rs forked a little distal to or at the level of the proximal side of pt in fore wing, slightly proximal to or at that level in hind wing. (In one teneral male from Borneo Rs forks decidedly beyond level of proximal side of pt in both pairs of wings). Fork narrow, with only two rows between its branches and with three marginal cells. 5 6 rows of cells between Rs-Rspl at the point of greatest divergence; 1 row of cells between M3-M4 in both pairs of wings (usually 1 - 2 doubled cells about the middle of their course); 1 row of cells between Cu1- Cu 2 in hind wing; all wings with 3 - 4 rows of cells in the intervening space between M4-Mspl where most widely separated. Pterostigma usually lacking a distinct brace-vein; in most individuals, however, a brace is accidentally present, at least so in one or two of the wings; pt long, brownish-yellow/ in colour, covering 3-4 underlying cells.

Abdomen of peculiar shape: basal segments cylindrical, very slightly tumid; segment 3 not constricted or only to the slightest extent; beyond the constriction the abdomen broadens very little, acquiring its maximum width towards end of segm. 4, from where the abdomen tapers again very slightly as fas as the end. Auricles exceptionally small (hardly 0.5 mm in length), armed with 3 minute apical teeth. Abdomen dark purplish- to blackish-brown with rich blue and green markings, as follows:-

Segment 1 with most of the sides blue-green and with a transverse light blue spot, occupying the apical half of the dorsum. Segm. 2 with bright blue-green AML and PL, occupying most of the sides; AD small, blue in colour; MD narrow, paired and likewise blue; PD large, paired, finely separated in the middle line, each of the spots trapezoidal, bright blue in colour. Segm. 3 with AL and ML blue, narrowly separated by the transverse carina; MD linear, blue, confluent with ML laterally; PD isolated, united mid-dorsally, forming a large semicircular blue spot, occupying about 1/3 of the whole length of segment. Segm. 4 - 8 with AL and ML rather narrow and in the form of marginal bluish streaks decreasing in size posteriorly; Ml) distinct, progressively more pointed cauded from before backwards; PD isolated, dark blue in colour, forming a conspicuous semicircular dorsal spot, which is finely divided by the longitidunal carina and about one-third as long as the posterior division of the segment on 4 - 6, one-fourth on 7, and in the form of paired spots on 8 and 9. Segm. 10 reddish-brown, its posterior border black. Ventral surface of abdominal segments brown.

Anal appendages: superior pair brown, their borders blackish-brown fringed with clark brown hairs interiorly; inferior appendage dark brown. Sup. anal apps. shaped exactly as shown on fig. 162 of MARTIN'S monograph (loc. cit .. p. 161); inf app. short, triangular, deeply channelled, apex with a narrow V-shaped incision, the tips acute and strongly upturned.

Female (ad.), - Resembles the male almost in all but sexual characters. Synthorax uniform dark greyish-brown with the slightest indication of some greyish-blue colouring on the middle of each mesepisternite. Nota and axillaries chrome-yellow, intermingled with green.

Legs reddish-brown, apices of anterior femora obscured.

Wings shaped as in the opposite sex. Membrane evenly tinged with yellow save for the extreme bases, which are hyaline (juv.), or deeply and evenly enfumed, especially towards the apices, the bases being hyaline or only palely tinted (ad.). Venational details very similar to male. Pterostigma long, pale ochreous, covering 3 - 4 cells.

Abdomen shaped much as in the opposite sex: widest at end of first segment, tapering to the end of segm. 7; base of 8 slightly constricted, but apically acquiring a little over the width of 7, then again slightly tapering to the end of abdomen. Coloration dark brown, basal segments intermingled with diffuse olive-grey; tergal margins and under surfaces light brown. Markings similar in principle to the male, but very indistinct- or obscured and decidedly smaller, especially PD, which is all but invisible on segments 6 - 9. Terminal segments apparently unmarked.

Ovipositor extending to about half-way the length of segm. 10. Dentigerous plate produced, trapezoidal in shape and rather swollen; laterally furnished with short bristles and. apically, occasionally with some microscopical teeth, on each side just before the origin of the spines; spines two in number, much shorter than in Gynacantha , but hardly shorter than the plate, divaricate, evenly and slightly downcurved apically. Shape of anal appendages unknown (fractured off in all specimens so far taken); basal portion (about 2 mm in length, extremely narrow, gently decreasing in width apically.

M. A. Lirzrrinck: Descriptions and records of S. E. Asiatic Odonata . 389

Length: ♂ abd. + app. 49 50.5, hw. 45.7 - 47, pt 3.9 4.3/3.8-4.0; 2 abd. 48.5 - 50.5, 51.5 - 53, pt. 4.0-4 5/3.7-4.3 mm.

The two Sumatran specimens do not differ in any Way from our series of Borneo.

This very distinct species has no near allies. The male superficially resembles a small Tetracanthagyna . Both sexes easily distinguished from all other are Asiatic Heliaeschnae by the long and narrow wings, and by the very narrow fork of Rs. which has only two rows of cells between its branches whilst there are only three marginal cells. The pterostigma is decidedly longer and the apices Of the wings are much more rounded off than in such species as simplicia (Karsch) and its ‘ double’, vanderweelei MARTIN. Neither the male nor the female show any narrowing of the abdomen at the third segment, whereas in the species just mentioned this segment in the male is strongly constricted basally, and at least slightly so in the female. The simple structure of the anal appendages of the male and the two - pronged dentigerous plate of the female may further serve to the easy recognition of bartelsi .

H. bartelsi has long been mistaken for H. simplicia (Karsch) , described also from Borneo, and until recently I thought it to be that species, following Martin's account in the monograph.

Now that l have examined KARSCH'S type of simplicia in the Berlin Museum, it is quite evident that the latter is entirely different from bartelsi , agreeing most closely with Martin's species vanderweelei , which was erroneously described from “ Liberia ” 1). I have compared the types of simplicia with a fine series of both sexes (from West Borneo) in the Buitenzorg Museum and found them agreeing in every respect. Not only is there a close similarity between the anal appendages and the dentigerous plates of simplicia and vanderweelei , but there is also a great resemblance in the venation, body-colouring and size. At the moment I can find no differences between them and l doubt if vanderweelei can be regarded as a valid species.

In the Berlin Museum is a male of this species from Palembang (E. Sumatra), identified with vanderweelei by Dr. E. SCHMIDT. The species H. vanderweelei is also represented in our collection by a good series of males and females, collected in the residencies of Palembang and Djambi, in East Sumatra. FORSTER 2) has proposed to create a distinct genus for the Asiatic species of the genus with the name Malayaeschna (generotype: Amphiaeschna simplicia Karsch

l) See RIS, Zool. Meded. Leiden. 10, 1927, 31 33, fig. 22 (apps. ♂), 23 (genit. ♀). p.

t) FORSTER, Jahrb. Nassau. Ver. Naturk. Wiesbaden, 62, 1909, p. 219.

390 TREUBIA DEEL 17, 1940, AFL. 4.

His reasons are that the latter have a longer t and wings more pointed relatively than the African species; and that whilst Malayaeschna has a four- or six-toothed dentigerous plate, the African Heliaeschnae have a two-pronged plate. It is worth remark that the dentigerous plate of the female of H. uninervulata , MARTIN is armed with three spines, and that the new Asiatic H. bartelsi approaches the Ethiopean group in the simple structure of the male superior appendages and the two-pronged genital plate of the female. For these reasons alone it does not seem advisable to accept FORSTER'S name Malayaeschna .