Indocnemis marijanmatoki, Phan, Quoc Toan, 2018

Phan, Quoc Toan, 2018, Notes on the genus Indocnemis Laidlaw, 1917 in Vietnam with description of Indocnemismarijanmatoki sp. n. (Odonata, Zygoptera, Platycnemididae), ZooKeys 809, pp. 15-29 : 19-24

Indocnemis marijanmatoki sp. n. Figures 7, 11, 12, 13-16, 21, 22, 25-28, 31

Type specimens.

Holotype. A mature male, folded wings in triangular envelope. Original label: " Indocnemis marijanmatoki sp. n., Hon Ba Nature Reserve, Nha Trang city, Khanh Hoa Province, Vietnam (12°07'10.0"N, 108°5'51.0"E, 1503 m a.s.l.), T.odo.16041705, Q.T. Phan leg", “HOLOTYPE” [red handwritten label]. Paratypes. 1 mature male, 1 mature female, same date, location and collector as the holotype. All type specimens are deposited in the Zoological Collection of Duy Tan University, Da Nang city, Vietnam.

Other specimens examined.

Two mature males, collected in a small stream on the main route to the top of the Kon Ka Kinh Mountain (14°19'83.5"N, 108°24'31.9"E, 1450 m a.s.l), Dak Hro village, Dak Roong commune, K’Bang District, Gia Lai Province, 09 April 2018, To Van Quang leg.

Etymology.

Marijanmatoki , a noun in the genitive case, after Marijan Matok (born 28 March 1972) of Ulm-Söflingen, Germany, in appreciation of his support of the author’s odonatological research in Vietnam through the International Dragonfly Fund.

Diagnosis.

The new species differs from I. orang with a combination of the following characters: in the male, the marking on dorsum of synthorax is small, shield-shaped; S9-10 entirely black; cerci short, of the length as S10, without a robust basal spine; paraproct entirely black. In the female, the posterior pronotal lobe of the prothorax is rather small, semicircular-shaped.

Description of holotype.

Head (Fig. 21). Labrum, genae, mandible and postclypeus shining black; anteclypeus dark brown. Antennae black except paler apical part of first and second segments. Top of head matte black with two long stripes adjacent to median ocellus running towards the base of the antennae and two water drop-shaped yellow spots just posterior to postoccipital lobes.

Thorax (Fig. 21). Prothorax entirely black. Synthorax black with a large oval-shaped marking and another tiny stripe in mesepisternum. The large marking blue in life, but becoming pale yellow surrounding a smaller blue part after acetone treatment. Mesepimeron black, metepisternum black with a large yellow stripe adjacent to mesocoxa and covering spiracle, interrupted before end of segment. A large yellow marking covering most of metepimeron.

Legs (Fig. 21). Coxae pale brown. Femora and tibiae black. Tarsi and armature brown.

Wings (Fig. 31) hyaline with black venation, 24 and 20 Px in FW and HW, respectively. Pterostigma brown, covering 2 underlying cells.

Abdomen (Figs 11, 22). Segments entirely black excluded a large yellow marking laterally in S1 and ventral yellow line on S2 and a small whitish lateral spot on S10.

Genital ligula (Fig. 16) structurally simple with two long flagella.

Anal appendages (Figs 13-15, 22) black, except for dorso-apical margin of cerci, which are pale yellow. Cerci bearing a large ventral tooth near the apical portion. In lateral view, cerci as long as S10; in dorsal view, cercus narrowing distally and slightly pointed at apex. Paraproct longer than cercus, its tip directed medially and ending in a black tooth.

Measurements. HW 41 mm; abdomen (incl. appendages) 55 mm.

Variation in paratype male.

The paratype male differs from the holotype as follows: the blue marking on the mesepisternum slightly larger; the yellow marking in metepimeron not extending to the margin of metinfraepisternum as in the holotype; ventro-lateral S2 without yellow band and the pale marking on S10 bigger than in the holotype. In one male from Kon Ka Kinh National Park, cerci longer than S10, reaching the level of paraproct as in I. orang . Measurements ranges of hind wing 40 mm and abdomen (incl. appendages) 52 mm.

Description of female.

Head (Figs 25, 26). Labrum and postclypeus shining black; anteclypeus brownish; mandible and genae yellow, the lower margin of genae black. Dorsal head side matt black, ocelli pale yellow, there are two long stripes adjacent to ocellus and nearby two oval yellow spots. Posterior side of head black with two yellow spots as in male.

Thorax (Figs 12, 27, 28). Prothorax black, except two large oval spots at sides of middle pronotal lobe of pronotum; lower part of propleuron yellowish. Posterior pronotal lobe well developed, but only half as wide as middle lobe, rounded (Figs 27, 28). Mesepisternum black with a long and narrow antehumeral stripe; mesepimeron black, metepisternum black with a large yellow stripe, rounded at the end and covering spiracle and metathoracic cross sutures; this mark connected to yellow part of metepimeron and metinfraepisternum.

Legs. Coxae and trochanter yellowish. Femora black with yellow marks at base. Tibia, tarsus and armature black.

Wings. Hyaline, 23-24 and 20 Px in FW and HW, respectively. Pterostigma brown, covering 1.5-2 cells.

Abdomen (Fig. 12). S1 black with a large lateral yellow spot; S2-3 with a yellow latero-ventral band; S4 with two tiny yellow spots at segment margins; S5-7 with a tiny yellow spot at ventral-apical margin of each segment; S8-9 black with a large bluish marking dorso-apically on each segment; S10 black. Cerci black, ovipositor black with small yellow spot anteriorly and dorsally at apex.

Measurements. HW 41 mm; abdomen (incl. appendages) 55 mm.

Habitat and ecology.

At the type locality, the new species was found at a narrow (2-3 m wide), shallow stream with sandy bottom. Specimens were collected in April, which otherwise is early for other dragonflies and damselflies, so only Anotogaster sp. was found at the same stream. At the two localities where the new species was found, I. marijanmatoki sp. n. and I. orang occur at quite different elevations. The new spe cies occurs at very high elevations, from 1,400-1,500 m a.s.l., while I. orang is usually found in the areas ranging from 300-600 m a.s.l.

Discussion.

In the male, the cerci of Indocnemis marijanmatoki sp. n. are relatively short, as long as S10 and lack a robust basal spine (Figs 13-15), while in I. orang , the cerci are 1.5 times the length of S10 and have a robust basal spine (Figs 17-19); the paraprocts of I. marijanmatoki sp. n. are entirely black (Fig. 22), but those of I. orang are yellowish (Fig. 24); the dorsum of S9-10 of I. marijanmatoki is black (Fig. 22), while strikingly marked with blue in I. orang (Fig. 24); and finally, the bluish dorsal stripe extends above the mesepimeron, covering most of the mesepisternum in I. orang (Figs 8, 23) but is reduced to a smaller shield-shaped mark and another tiny oval spot in I. marijanmatoki (Figs 7, 21). Females of both species are very similar in appearance but differ clearly in the shape of the posterior lobe of the prothorax. In I. marijanmatoki sp. n., this structure is prominent, but clearly less wide and semicircular in shape (Fig. 28), whereas it is much wider in I. orang (Fig. 30). The yellow stripe on the dorsum of the head of all examined specimens of I. orang extends to the margin of the compound eyes (Fig. 29), just like in Thai ( Asahina 1985: 8, fig. 27) and Indian specimens ( Asahina 1997: 9, fig. 32), while these are divided into two stripes, never touching the margin of the compound eye (Fig. 26) in I. marijanmatoki sp. n.