Heliogomphus kalarensis Fraser, 1934

Sadasivan, Kalesh, Nair, Vinayan P., Palot, Muhamed Jafer, K., Abraham Samuel & Shereef, Anzil, 2022, Taxonomic notes on the genus Heliogomphus Laidlaw, 1922 (Odonata: Gomphidae), with a redescription of H. kalarensis Fraser, 1934 from southern India, International Journal of Odonatology 25, pp. 107-120 : 112-117

Heliogomphus kalarensis Fraser, 1934

( Figs 1 , 2C–F , 4 , 5B, 5D, 5F, 5H , 6 , 7D, 7E )

1922 Heliogomphus pruinans Fraser : Fraser, [new synonymy], Rec. Ind. Mus., 24, 416, 417, pl. xi, fig. 3.

1923a Heliogomphus pruinans Fraser, J. Bom. Nat. Hist. Soc. , 29, 63.

1924 Heliogomphus pruinans Fraser : Fraser, Rec. Ind. Mus., 26, 427, 473.

1925 Heliogomphus pruinans Fraser : Laidlaw, Philip. J. Sci., 28, 560.

1933 Heliogomphus kalarensis Fraser : Fraser, Ceylon J. Sci., B, 18, 29, fig. 4. [nom. nud.]

1934 Heliogomphus kalarensis Fraser : Fraser, Fauna Brit. India, Odonata, 2, 325, 329, 330, fig. 101b.

1942 Heliogomphus kalarensis Fraser : Fraser, Trans. R. Ent. Soc. Lond., 92 (2), 335, 336, 339, 340, fig 3 (7), plate 1 (3).

1966 Heliogomphus kalarensis Fraser : Kimmins, Bull. Br. Mus. nat. Hist. (Ent.), 18 (6), 173–227.

1985 Heliogomphus kalarensis Fraser : Allen, Davies & Tobin, Soc. Int. Odonatol. Rapid Comm. (Suppl.), 5, 31.

1989 Heliogomphus kalarensis Fraser : Lahiri. Proc. Ninth Intl. Symp. Odonat., 4, 53–56.

1995 Heliogomphus kalarensis Fraser : Prasad & Varshney, Oriental Insects, 29 (1), 400.

1997 Heliogomphus kalarensis Fraser : Steinmann H 2, 123.

1995 Heliogomphus kalarensis Fraser : Tyagi B.K. Zoos Print Journal, 12 (10), 8.

2000 Heliogomphus kalarensis Fraser : Tsuda A Distributional List of World Odonata .

2005 Heliogomphus kalarensis Fraser : Subramanian, Dragonflies and damselflies of Peninsular India, 114.

2007 Heliogomphus kalarensis Fraser : Subramanian, Odonata —Biology of Dragonflies, 264.

2009 Heliogomphus kalarensis Fraser : Subramanian, A checklist of Odonata ( Insecta) of India, 14.

2011 Heliogomphus kalarensis Fraser : Kiran & Raju, Malabar Trogon, 9 (3), 32.

2013 Heliogomphus kalarensis Fraser : Kiran & Raju, Dragonflies and Damselflies of Kerala, 153.

2013 Heliogomphus kalarensis Fraser : Babu, Subramanian & Nandy, Rec. Zool. Surv. India, 347, 5, 25.

2014 Heliogomphus kalarensis Fraser : Emiliyamma, Rec. Zool. Surv. India, 114 (1), 59, 64.

2017 Heliogomphus kalarensis Fraser : Subramanian & Babu, A checklist of Odonata ( Insecta) of India, ver. 3.0, 26.

2018 Heliogomphus kalarensis Fraser : Subramanian, Emiliyamma, Babu, Radhakrishnan & Talmale, Atlas of Odonata ( Insecta) of Western Ghats, India, pp. 223.

2020 Heliogomphus kalarensis Fraser : Kalkman, Babu, Bedjanic, Coniff, Gyeltshen, Khan, Subramanian, Zia & Orr, Zootaxa, 4849 (1), 34.

2020 Heliogomphus kalarensis Fraser : Subramanian, Babu & Emiliyamma, Faunal Diversity of Biogeographic Zones of India, Western Ghats, 234.

2021 Heliogomphus kalarensis Fraser : Paulson, Schorr & Deliry, World Odonata List.

2021 Heliogomphus kalarensis Fraser : Nair, Samuel, Palot, & Sadasivan, Entomon, 46 (3), 192, 228.

2022 Heliogomphus kalarensis Fraser : Nair, Samuel, Palot & Sadasivan, Malabar Trogon, 20 (1), 21.

2022 Heliogomphus kalarensis Fraser : Gopalan, Sherif & Chandran, J. Threat. Taxa, 14 (2), 20655.

2022 Heliogomphus kalarensis Fraser : Nair, Sadasivan, Vijayakumaran, Nayakkan, Palot, & Samuel, Entomon (in press).

2022 Heliogomphus kalarensis Fraser : Sadasivan, Samuel, Nair & Murukesh, Entomon (in press).

Diagnosis

Antehumeral stripe separated from the mesothoracic collar; sides of thorax with two black stripes; antehumeral stripe straight; superior humeral spot present; external spine of cerci of moderate size; lateral spine of cerci followed posteriorly at the most by a very shallow concavity; cerci broadening towards the apex and with the outer margin strongly angulated; outer margin of cerci bent at less than a right angle; female vesicle simple ( Fraser, 1942).

Specimens examined (n = 6 males)

Holotype

NHMUK # 013384589 , male, Kallar , Nilgiris, Tamil Nadu, March 1916, Col. Fraser FC; NHMUK # 013324357 , male, Buruliyar , Nilgiris , Tamil Nadu, 29.vii.1921, Col. Fraser FC; TORG # 1018 , male, Pandimotta , Shendurney , Kerala , 01.v.2022, Col. Kalesh Sadasivan; TORG # 1019 , male, Ponmudi , Trivandrum , Kerala, 02.v.2022, Col. Kalesh Sadasivan; TORG # 1020 , male, Ponmudi , Trivandrum , Kerala, 01.vi.2022, Col. Kalesh Sadasivan; TORG # 1021 , male, Kanichar, Kannur, Kerala, 12.vi.2022, Col. Vinayan P. Nair.

Other specimens studied in field (not collected) (n = 12 males). 5 males, Pandipathu, Peppara WLS, Trivandrum , Kerala, May 2022, Kalesh Sadasivan; 4 males, Edamalakudi, Munnar , Kerala, May 2022, Kalesh Sadasivan; 3 males, Kanichar , Kannur, Kerala, June 2022, Vinayan P. Nair.

Measurements (in mm) (n = 4). Total length (including appendages) 48–50, abdominal length 34–36, forewing length 32–33, hindwing length 32–32, HFL 5–6.

Description of male

( Figs 1 , 2C–F , 4 , 5B, 5D, 5F, 5H , 6 , 7D, 7E )

Head ( Figs 4A , 6B–D ). Eyes anteriorly pale green, anterodorsally darker, and inferolaterally greenish white. Genae brownish black. Mandible black in the middle, marked by a large triangular yellowish white patch. Labium translucent yellowish brown posteriorly, and anteriorly black at the tooth. Labrum black, bearing two large triangular yellowish white patches on each half, its entire free edge bordered thickly with black. Anteclypeus dark blackish brown. Postclypeus shiny black. Antefrons and postfrons black, the latter bearing a large transverse yellowish white band. Vertex shiny black. Occipital bar matte black, and postocular lobe shiny black. Ocelli waxy white. Antennal segments black. Long pale amber-brown setae along the inferior border of the anteclypeus and on the labium.

Prothorax ( Fig. 4A ). Ground colour black, marked with pale lemon-yellow spots. In dorsal view, anterior lobe with a transverse yellow band, which occasionally bears two semicircular, black, paradorsal spots; middle lobe black, occasionally with a pair of small, yellow, paradorsal spots; posterior lobe entirely black, rarely with a mid-dorsal yellow spot. In lateral view, the lateral portion of the middle lobe with a yellow spot. Proepisternum yellow and proepimeron black. Forelegs generally black, but the anterior sectors of the coxae and trochanter yellow. Spines and claws black.

Synthorax ( Figs 4A , 6A, 6C, 6D , 7D, 7E ). Ground colour black, marked with pale lemon-yellow. In dorsal view, mid-dorsal carina black, the yellow mesothoracic collar narrowly bisected by it; antehumeral stripes well developed, almost reaching the antealar sinus dorsally; upper humeral spot variable, absent in three out of the six specimens examined. In lateral view, the mesepisternum black, bearing the yellow mesothoracic collar and the antehumeral stripes that taper dorsally, short of extending to the antealar sinus. Mesepimeron black, bearing a large central yellow dorsal stripe that almost reaches the wing base. Mesinfraepisternum dorsally black and inferiorly marked with yellow. Metepisternum black and marked with a large yellow stripe that almost fills it. Metepimeron wholly yellowish. The interpleural suture bordered with black. Metinfraepisternum mostly yellow, borders black. Metathoracic spiracle brown bordered with black. The mid- and hindleg coxae, trochanter, femur, and tibia are all black. The hind femur long, reaching the junction of abdominal sternites S1 and S2.

Wings ( Figs 2C, 2E , 6E ). Hyaline; Pt of both wings black, parallelogram-shaped, occupying almost five cells; borders slanting laterally; inferior border curvilinear. Pt length three times its breadth at its middle. Nodal range in FW: Ax 11–17 & Px 13–15; HW: Ax 10–12 & Px 11–13.

Abdomen ( Figs 2C, 2E , 6A, 6F, 6G ). Ground colour shiny black and marked with pale lemon-yellow as follows: S1 inferolaterally and laterally pale yellowish white, smudged with brown dorsolaterally; S2 auricle and adjoining region With a small spot near its posterior edge; S3–6 marked with very small, triangular, basolateral streaks, the ventral parts of which extending posteriorly by not more than an anterior fifh of the segments; S7 marked with a ventrally incomplete annulus, this broad dorsal patch extends laterally, but is interrupted ventrally; a small triangular spot on the posterior border of S7; S8 with a thick incomplete annulus, ending mid-laterally, the posterior edge with a small triangular spot. S9–10 black and unmarked. Auricle on S2, in ventral view, elliptical in outline, with a series of small, medially directed spines on its posteromedial and medial portion. In dorsal view, a mid-dorsal yellow line extends from S1 almost to the caudal border of S5; dorsal streak reduced in S6, reaching only its anteriormost fifh; the basal dorsal patch in S7 has a short bifid paradorsal extension posteriorly; S8 and 9 have a small triangular dorsal extension posteriorly.

Anal appendages ( Figs 2D, 2F , 4D, 4E, 4F , 5F, 5H ). Ground colour of cerci and epiprocts black; the part of the cerci distal to the lateral spine is white dorsally, brown ventrally, and its extreme tip is smudged with brown and ends in a black hook. Length of cerci equals that of S 10 in dorsal view. Lateral horns of the epiproct straight, directed posterolaterally, tip finely hooked. In dorsal view, the male cerci are directed laterally, lateral profile of the cerci sinuous, short spine directed straight laterally in its basal third, its extreme tip curved laterally in on itself.

Secondary genitalia ( Figs 4B, 4C , 5D ). Colour amber-brown to dark brown. Anterior hamule (AH) shorter than the posterior hamule ( PH) in lateral view, distal half tapering and curved into a hook with its tip directed posterolaterally; Body of PH broader than AH, tapering and curved gradually towards its tip; tip of PH truncated, flat, shallowly notched, and directed anteriorly, lying along its counterpart in the midline. Ligula broad, higher than the PH, directed posteriorly, covering the distal section of the stem and the middle segment of the vesica spermalis. The structure of the VS and PH is illustrated in Fig. 4C . The middle segment of the vesica spermalis, in lateral view, has a triangular extension directed ventro-posteriorly ( Fig. 5D ).

Distribution

Kerala: Nilgiri–Silent Valley landscape—Silent Valley NP ( Nair et al., 2021); Coorg landscape—Kanichar and Kottiyoor WLS, Kannur; Munnar landscape—Mangulam and Edamalakudi of High Range subunit; Agasthyamalai landscape—Chinnapullu in Trivandrum Territorial Division, Ponmudi Hills in Kulathupuzha Reserve, and Peppara WLS (Nair et al., in press). Tamil Nadu: Kallar, Mettupalayam, Kotagiri Ghat in Nilgiris ( Fraser, 1934, 1942) and Kotagiri Ghat Kotagiri Ghat in Nilgiris (Kimmins, 1966).

Annotations

In addition to the diagnostic features mentioned above, examination of the holotype in the BNHM (NHMUK # 013384589 Heliogomphus kalarensis Fraser, 1934 ), fresh specimens from the Western Ghats (12 males, not collected), and voucher specimens in the TORG collection (4 males) revealed that the inferior appendage of this species is divergent, robust and straight, with its extreme tip hooked and recurved ( Figs 2D, 2F , 4D–F , 5F, 5H ). Coloration is variable in this species: the sides of the thorax sport three yellow stripes of which the middle one is variable in thickness, making differentiation from H. promelas difficult using images alone. Although the presence of an upper humeral spot is di-

agnostic of H. kalarensis , this marking is variable, too, absent in three out of the six specimens examined. The yellow occiput is said to be a unique character to distinguish H. kalarensis from H. promelas , but we found this feature to be variable as well and absent in five out of six specimens of H. kalarensis . The robustness of the outer spine on the cerci and the curvature of the tip was found variable in H. kalarensis and hence does not represent a solid character to distinguish this species from H. promelas . The spots on the prothorax were individually variable.

Furthermore, we examined the lectotype of Heliogomphus pruinans Fraser, 1922 (NHMUK #013324357) and found that the epiprocts conform to those of H. kalarensis and not of H. promelas ( Fig. 2F ). As a consequence, this taxon name is removed from the synonymy of H. promelas and is placed as a senior synonym in that of H. kalarensis . According to the International Code of Zoological Nomenclature (ICZN, 2000), the prevailing name should be retained as a nomen protectum, if a senior synonym or homonym has not been used as a valid name afer 1899 (Article 23.9.1.1) and the junior synonym or homonym has been used as valid by at least ten authors in 25 scientific works published in the immediately preceding 50 years and encompassing not less than ten years (Article 23.9.1.2). Since these criteria are met by the name H. kalarensis Fraser, 1934 , which was used in 27 scientific works, the name Heliogomphus pruinans, Fraser, 1922 is synonymized with H. kalarensis Fraser, 1934 , a nomen protectum in accordance with ICZN Article 23.9.1.2, suppressing its lesser used senior synonym.

Figures

Figure 1. Map of southern India, showing landscapes with spot records of Heliogomphus kalarensis and H. promelas.

Figure 2. Specimens of Heliogomphus from the BMNH, London: (A) Dorsal habitus of H. promelas NHMUK #014666648, male, Burliyar, Nilgiris, Tamil Nadu; (B) close-up in ventral view of epiprocts of H. promelas, NHMUK #014666649; (C) dorsal habitus of H. kalarensis holotype, male, NHMUK #013384589, Kallar, Nilgiris, Tamil Nadu; (D) close-up in ventral view of epiprocts of H. kalarensis, holotype male, NHMUK #013384589; (E) dorsal habitus of H. pruinans NHMUK #013324357, male, Buruliyar, Nilgiris, Tamil Nadu; (F) close-up in ventral view of epiprocts of H. pruinans, NHMUK #013324357. Photos courtesy of BMNH, London.

Figure 4. Specimen of H. kalarensis, TORG #1018, male, Pandimotta, Shendurney, Kerala: (A) Dorsal view of synthorax; (B) ven- tral view of genital fossa; (C) right lateral view of vesica spermalis extruded in ventral exposure; (D) right lateral view of anal appendages; (E) ventral view of anal appendages showing straight epiprocts; (F) dorsal view of anal appendages showing cerci.

Figure 5. Comparison of H. promelas and H. kalarensis males: (A) Ventral view of right auricle of H. promelas; (B) ventral view of right auricle of H. kalarensis; (C) expansion on the middle segment of the vesica spermalis of H. promelas; (D) expansion on the middle segment of the vesica spermalis of H. kalarensis; (E) ventral view of the epiprocts of H. promelas; (F) ventral view of the epiprocts of H. kalarensis; (G) dorsal view of the cerci of H. promelas; (H) dorsal view of the cerci of H. kalarensis.

Figure 6. Heliogomphus kalarensis in life: (A) Lateral view of the whole insect; (B) close-up of the head; (C) lateral view of head and synthorax; (D) dorsal view of the head, prothorax, and synthorax; (E) venation; (F) lateral view of S7–10 and appendages; (G) dorsal view of S7–10 and appendages.

Figure 7. Schematic overview of the variation in the markings on the synthoraces of H. promelas and H. keralensis: (A) H. promelas; (B) H. promelas melanotic variant; (C) H. promelas melanotic variant; (D) H. kalarensis with upper humeral spots; (E) H. kalarensis without upper humeral spots.