Anormogomphus heteropterus, Joshi, 2022

Joshi, Shantanu, 2022, Platygomphus benritarum sp. nov. and rediscovery of Anormogomphus heteropterus Selys, 1854 (Odonata: Anisoptera: Gomphidae) from Tezpur, Assam, India, International Journal of Odonatology 25, pp. 62-71 : 63-67

publication ID	https://doi.org/10.48156/1388.2022.1917172
DOI	https://doi.org/10.5281/zenodo.15576302
persistent identifier	https://treatment.plazi.org/id/03CEA72A-FF93-0D1A-EE36-7646117B993A
treatment provided by	Felipe
scientific name	Anormogomphus heteropterus
status	sp. nov.

Treatment

Anormogomphus heteropterus View in CoL sp. nov.

Figs 1–2 View Figure 1 View Figure 2

Material examined

Holotype

m# ( IBC-BO403 ): Parvati Nagar (N 26.6262, E 92.7752, alt.: 71 m), Tezpur , Assam, India, 25.iv.2020, Anuja Mital leg. GoogleMaps

Description of male

Head ( Fig. 1a View Figure 1 ). Eyes pale brown, darker dorsally. Face uniformly yellow,marked as follows: labium light brownish, labrum with medial and postclypeus with paired dark yellow markings, and frons slightly greenish. Labrum 2.5 times as wide as long, frons expanded. Ocellar region depressed and black between lateral ocelli and frons. First antennal segment black at the base, remainder yellow; second antennal segment black at the base, remainder orange-yellow; filament black. Median ocelli wider than lateral ocelli. Vertex and occipital ridge yellow, black at their boundary.

Thorax ( Figs 1b, d View Figure 1 ). Prothorax yellow, with a distinctive black marking, widely expanded on anterior lobe, center of median lobe with paired yellow spots.Pterothorax yellow, marked with black: anterior portion of mesostigma, faint L-shaped markings along dorsal carina, two nail-shaped markings pointing forward on mesepisternum, thin stripe across upper margin of mesepimeron, junction of metepimeron and metepisternum faintly black. Antealar ridge conspicuous, black, and lined with small black spines, junction of dorsal carina forming a small, sharply pointed spine approximately midway between wing base and mesostigma.

Legs black, marked with blackish brown: stripes across tibiae, posteriorly, two stripes on femur, fainter on metafemora. Covered with long, black spines across mid-axis; spines on femur small and sparse. Claws black.

Wings ( Figs 1c, e View Figure 1 ) hyaline, membrane extended and yellow, pterostigma and costal margin pale brown, pterostigmal brace present. Antenodals (1 st and 4 th primary) 10 on FW, 7 (right), 8 (lef) on HW. Postnodals 7 on FW, 7 (lef), 8 (right) on HW. Median space and triangles not crossed. One cubito-anal vein each in all wings. Hind margin of HW not excavated, smoothly rounded. Anal triangle one-celled, indistinctly defined. Anal loop absent. Discoidal field of FW starting with two cells, expanded to 8 cells towards margin. MA continuous to wing margin without any branching. Single row of cells between CuA and MP, cells in 2–4 rows near margin. Single row of cells between RP 2 and IRP 2 throughout, two rows in lef HW near margin.

Abdomen ( Figs 1b, d View Figure 1 ). Ground color on S1–2 yellow, S3 to anterior half of S7 bluish-gray,yellow from there. Auricles small, yellow; covered with black spines. Marked black as follow: S1–7 with annules at posterior margin, short on S1, longitudinal paired black markings on S2–6: markings connected to black rings on S3–6, faint black spots on S7–10: near posterior border on S7–8, at anterior margin on S9–10. Dorsal section of S10 extended, lateral margin excavated. S10 is expanded between branches of cerci; a hood-like lamina is present, covering downwardly curved, horn-like, paired structures with black apices.

Vesica spermalis ( Figs 4a–c View Figure 4 ). Hamuli yellow. Anterior hamuli thin, long, ending in a shoulder and anteriorly pointed hook, apical spine black. Posterior hamuli long, saddle-shaped, and covered with bristles; anterior margin curved. V 1 rounded, junction of V 1 and V 2 sharply curved. V 3 simple, laterally slightly expanded with two yellow spots on ventral face. V 4 dark brown, rounded; apices excavated ventrally ending in a small curved filament.

Caudal appendages ( Figs 4d–f View Figure 4 ). Cerci extended 1.6 times as far as epiproct. Cerci blade-shaped, darker on inner side, with a small basal spine, lower margin curved slightly inwards. Epiproct fused at base, widely divergent, appearing triangular in lateral view, upper margin ridge-like; ending in upwardly pointed black spines.

Measurements. Abdomen + caudal appendages = 27.1, FW = 24.6, HW = 23.2.

Discrepancies in previous illustrations

Three different sources have provided illustrations of the caudal appendages of Anormogomphus heteropterus , viz., 1) Selys & Hagen (1858), 2) unpublished watercolor painting by Severin (see Material and methods for the link), and 3) Fraser (1926; republished in 1934). These three sources do not agree well with each other, and the first two are very schematic, not showing any finer details of the structure. Only Drawing 1 ( Fig. 4a View Figure 4 ) depicts the structure of cerci accurately. In Drawing 2 ( Fig. 4b View Figure 4 ), the basal spine of cerci is not figured at all, whereas in Drawing 3 ( Fig. 4c View Figure 4 ) the basal spine of cerci seems exaggerated, and the paraprocts are very thin and curved sharply upwards. In the holotype male, the cerci are broken, which might explain the discrepancy in the illustrations by Selys, especially with regard to the first two of the three illustrations mentioned above. The third drawing in Fig. 4 View Figure 4 a-iii seems to be showing the broken appendages of the holotype (compare with Fig. 3c View Figure 3 ). The male described in the present study has a peculiar structure at the base of the caudal appendages (highlighted with an arrow in Fig. 2d View Figure 2 ), made up of two lobes with black apices. These structures appear to be sclerotized extensions of the S10, but they were not mentioned in any description or considered in any illustration of this species. From the examination of the type specimen it is clear that they are present (pointed out with an arrow in Fig. 3d View Figure 3 ). Additionally, in Fraser (1926, p. 735), the figure for A. kiritshenkoi Bartenev, 1913 clearly shows these structures, but they are not explicitly discussed anywhere. This evidence clearly suggests that these basal structures are a characteristic of the genus Anormogomphus Selys, 1854 , but this still needs to be confirmed and described for A. kiritshenkoi by studying fresh specimens.

Diagnosis

Superficially, this species resembles some members of Burmagomphus Williamson, 1907 , Cyclogomphus Selys, 1854 , and Platygomphus Selys, 1854 . From these genera it is differentiated by: (a) single-celled anal triangle ( Fig. 1c View Figure 1 ), (b) base of HW rounded (not excavated; Fig. 1c View Figure 1 ), (c) lateral margin of S10 curved ( Fig. 2e View Figure 2 ), (d) shape of caudal appendages ( Figs 2d–f View Figure 2 ), and (e) shape of vesica spermalis ( Figs 2a–c View Figure 2 ). This species belongs to the genus Anormogomphus based on the shape of its caudal appendages (cerci pointed with basal spine, and epiproct divaricate), tornus of HW rounded with a single-celled anal triangle, anterior hamuli with an apical hook, and a pale ground coloration with an unmarked face.

Anormogomphus heteropterus differs from A. kiritshenkoi Bartenev, 1913 by: (a) cerci with a reduced basal spine (basal spine prominent in the former), (b) smaller size (abdomen length 25–27 vs. 29–31 in A. kiritshenkoi , (c) thorax with black markings (unmarked in the former), and (d) black annules with dorsal markings on S1–7 (abdomen unmarked in A. kiritshenkoi ). Anormogomphus kiritshenkoi also has a much more westerly distribution with no known records from east of Kashmir in India.

Habits and habitat

This species was observed on the terrace of a residential building while resting on an ornamental plant (Dracaena sp.) at around 18.00 h. This building is situated in a semi-urban area, surrounded by many buildings. There are some ponds nearby and the Brahmaputra River is ~ 1 km away. Anormogomphus spp. are weak fliers known to occur in sandy areas. The locality in which our single male was encountered is most definitely not the natural habitat of this species, and the banks of Brahmaputra River nearby and the surrounding region might be where this species breeds. The male observed by us appeared to have freshly emerged judging by its shiny wings and abdomen.