Amphiaeschna ampla basitincta, M.A. Lieftinck, 1940

M. A. Lieftinck, 1940, Descriptions and records of South-East Asiatic Odonata (II), Treubia 17 (4), pp. 337-392 : 385-386

Amphiaeschna ampla basitincta , subsp. n.

Material studied: — 1 ♂, 1 ♀ (ad.), S. \\ Sumatra, Benkoelen residency, / Tandjong Sakti near Pageralam , 600 m alt., May 27, 1935 (♂, holotype) Moeara Tenam. 250 m alt., June 16 - 23, 1935 (♀, allotype), M. E. Walsh leg., in the Buitenzorg Museum

Both sexes differ very strikingly from typical ampla in the greater extent of the brown basal patch to the fore and hind wings.

Male (ad.). ~ Base of fore wing dark burnt-brown, this colour extending to as far as Ax2 in c; to half-way between Ax2-3 in sc; to the second cross-nerve in m; and to half-way between second and third Cross-nerve in cu. Base of hind wing similarly coloured to as fas as Ax, in c and sc (the costal half of c ÜYMIYIG; basal antenodals in sc not counted); to the second cross-nerve in m; and to half-way between first and second cross-nerve in cu; a small basal spot 01 the same colour in each of the two basal cells of the anal triangle. Body-colour faded.

Superior anal appendages a trifle broader, and more abruptly narrowed apically, than in ampla ampla , the distal half of each slightly outbent; otherwise identical with the typical race (e. g., ampla , length to breadth 6.8: 1.2; basitincta , 6.6: 1.5 mm).

Wing-bases marked with dark brown similarly, though slightly less extensively, as in the female of typical ampla from Java.

Female (ad.). — Body-colouring dark reddish brown; all yellow and green markings faded and unapparent.

Wings hyaline, anterior pair with a large, diffuse patch of pale brown in the area between nodus and pterostigma, broad at the costa, narrowing towards and not quite reaching the hinder border of wing; this patch very similar to typical ampla but more extensive and decidedly deeper in tint. There is, in addition, a small brown nodal spot in both pairs of wings filling up part of the costal cell between nodus and Pz .. Basal patch dark burnt-brown, paler distally; cell-middles of c and m paler brown. In fore wing it extends diffusely as far out as A 16-, in c and sc; to the arculus in m; to almost as far as ti in cu; and from there in a curve to the posterior border of the wing, filling up almost the basal half of the anal area. In the hind wing the basal patch is more sharply limited, extending to beyond level of arculus in c and sc (Ax8-9 in sc); than abruptly back to the arculus in m, to the proximal side of ti in cu, and from there in line with this nervure to the border of the wing.

Genital plate (dentigerous plate) identical in shape to that of typical ampla 1 finely denticulate.

1) See F C. FRASER, Treubia, 8, 1926, 474, fig. 2 (nec 3!) - p.

Anal appendages also very similar, though comparatively less slender, and with the mid-rib broader (e.g., ampla , length to breadth 7.3: 1.5; basitincta , 7.0: 1.7 mm). Length: ♂ abd. 54 + 6.6, hw. 54. pt. 3.2/3.0: ♀ 52 + 7, 55, 3.2/3.0 mm. Up to the present in Sumatra the well known Javan species Amphiaeschna ampla has not been observed. In Java ampla is a moderately common species in wooded districts, inhabiting low country up to about 800 metres above sealevel. It is strictly nocturnal in habits and therefore seldom seen on the wing. 'The discovery of a subspecies of ampla in Sumatra means a welcome addition to our knowledge of its distribution.

The extent of the blackish-brown basal patch of the wings of typical ampla is remarkably constant in a series of 38 males and 22 females examined, from various localities scattered all over the island of Java,

MARTIN in his monograph gives excellent wing-photographs of both sexes of typical ampla from Java 1), which may conveniently be consulted in com- parison with the above description of A. a. basitincta .

Figures

Fig. 2. Ventral aspect of seminal vesicle (top) and left side-view of anal appendages of Euphaea subnodalis Laid., from Mt. Marapok (bottom).