Indigryllus sagani Jaiswara & Robillard, 2022

Jaiswara, Ranjana & Robillard, Tony, 2022, A new species of Indigryllus (Orthoptera, Gryllidae, Eneopterinae, Xenogryllini) from Kerala, India, with first data on acoustics and natural habitat, Zootaxa 5205 (6), pp. 532-546 : 534-535

Indigryllus sagani Jaiswara & Robillard sp. nov.

Figures 1–10

Type material. Holotype, ♂, INDIA: Kerala, Kasargod, Nileshwar, Koottappuna , ~ 19 m a.s.l., 06.VI.2021, 12°17’03.0”N 75°09’36.8”E, Sreebin S. leg., RJINS-163 (ZSI) . Allotype — ♀, RJINS-164, same locality as holotype (ZSI) . Paratypes (6♂, 3♀), same information as holotype, V –VII.2021: 5♂ (RJINS-161, 165, 166, 171, 172); 2♀ (RJINS-169, 170); 1♂, ex-RJINS162 (MNHN-EO-ENSIF11149); 1♀, ex-RJINS167 (MNHN-EO-ENSIF11150).

Additional specimens and observations. INDIA: Kerala, Kasargod, Nileshwar, Koottappuna , ~ 19 m a.s.l., 12°17’03.0”N 75°09′36.8”E, Sreebin, leg.: 1♀, on leaf, night, 28. V.2022, https://www.inaturalist.org/ observations/119077595 ; 1♂, on leaf, night, 28. V.2022, https://www.inaturalist.org/observations/119077537; 1 juvenile, on leaf, night, 26.IV.2022, https://www.inaturalist.org/observations/113058320; 1♀, on soil, night, 6. VI.2021, https://www.inaturalist.org/observations/81891957; 1♀, on leaf, night, 29. V.2021, https://www. inaturalist.org/observations/80754108; 1♂, stridulating on shrub, night, 22. V.2021, https://www.inaturalist. org/observations/79899381; 1 juvenile, night, 9. V.2021, https://www.inaturalist.org/observations/78083841; 1 juvenile, on leaf, night, 2. V.2021, https://www.inaturalist.org/observations/76596447. Kerala, Thavinhal , 11.84881, 75.95213, 1♂, on vegetation, 30.IV. 2017, M. Muzzatti leg., https://www.inaturalist.org/observations/18431227 . Kerala, 11.134528, 76.312889, 1 juvenile, 14XI.2020, Balakrishnan Peroth leg., https://www.inaturalist.org/ observations/64936698 .

Type locality. Koottappuna , Kasargod, Kerala, India .

Distribution. In addition to type locality, the new species is known from two other districts of Kerala, i.e. Wayanad and Malappuram, based on observations from iNaturalist (see above, Fig. 1 ). The identification of these two specimens as I. sagani sp. nov. is tentative and will need confirmation based on specimen study.

Etymology. The species is named after the American astronomer, Carl Edward Sagan in recognition of his significant contributions to scientific research on extra-terrestrial life.

Diagnosis. Indigryllus sagani sp. nov. differs from I. kudremu by the male genitalia with pseudepiphallic lophi shorter and laterally winged, and by the following external characters: smaller body length; female subgenital plate posterior margin weak indentation, much wider than long ( Fig. 2 ); 2A vein on male FWs forming obtuse angle; black patch between veins 1A and 2A extended more laterally towards plectrum.

Description. Body size average for the tribe. Most characters similar to I. kudremu , from which the new species differs as follows. Eyes slightly larger and more globular ( Fig. 3B ). Pronotum posterior margin slightly convex in the middle ( Fig. 3A ). TI with two inner and one outer apical spurs.

Male. FWs with somewhat parallel lateral margins (slightly widening posteriorly in I. kudremu ). Vein 2A forming an obtuse angle; black patch between veins 1A–2A extended much more laterally towards plectrum; two harp veins (three occasionally); proximal part of first harp vein arising almost at 90° angle from CuA vein; cell d1 long, usually divided into two sub-cells (occasionally undivided or divided into three sub-cells); FW apex broader; apical field with 2–3 cell alignments. Mirror slightly wider than long ( Fig. 4A ).

Male genitalia. Pseudepiphallic lophi long, strongly sclerotized, bilaterally winged with less sclerotized structure, extending from anterior base upto 4/5 th of posterior end; lophi apex with short and stout inner hook, converging towards each other, making U-shape appearance; pseudepiphallic parameres strongly sclerotized, short, slender, shallow bifurcation on posterior end, anterior end somewhat cone-shaped, sub-anteriorly short projection on inner side ( Fig. 5A–E ).

Female. FWs dorsal field with five strong longitudinal veins. 1A vein either bifurcated from 2/3 rd or half of FW length. Lateral field triangular ( Fig. 4B ). FW apex broader compared to I. kudremu .

Female genitalia. Subgenital plate posterior margin weakly indented. Copulatory papilla with a basal cylindric sclerite and a narrower membranous apex ( Fig. 5F–G ).

Coloration. Individuals of this new species are found in two syntopic color morphs, a dark one ( Figs 6C, 6D , 7 , 8 ) and a paler one ( Fig. 6A, 6B , 7 , 8 ). The dark color morph is mainly dark gray brown, while the paler form is brown, with a median dark brown band along the whole body ( Fig. 6A ).

Habitat. Adults of I. sagani sp. nov. were seen during the months of May and June in Koottappuna, Nileshwar (a municipality in Kasaragod, Kerala), while juveniles were first observed in April. Individuals were found at low elevation, less than 100 meters above sea level, adjacent to a rubber plantation with dense undergrowth. The region has dense vegetation ( Figs 7 & 9 ), consisting of plant species such as Camonea vitifolia, Ixora coccinea, Chromolaena adorata , Dioscorea bulbifera , and over a hundred other species of wild plants ( Figs 7 , 8 , 9 ).

Figures

FIGURE 1. Map showing the current distribution of Indigryllus: the red circle indicates the type locality of I. kudremu; the blue circle indicates the type locality of Indigryllus sagani sp. nov.; the orange circles indicate the localities corresponding to iNaturalist records of Indigryllus sp. for which no specimen could be studied tentatively identified as I. sagani; the pink circle indicates a iNaturalist record identified as Indigryllus sp. which could belong to a new species. Map by Miguel Valenzuela, 2020, with permission (IG: @mappdoutofficial)

FIGURE 2. Indigryllus sagani sp. nov.: (A) dorsal view of male subgenital plate, (B) dorsal view of female subgenital plate and (C) dorsal view of male supra anal plate.

FIGURE 3. Indigryllus sagani sp. nov.: (A) dorsal view of male head and pronotum, (B) front view of face, (C) lateral view of male head and pronotum. Scale bars: A, C, 5 mm; B, 1 mm.

FIGURE 4. Indigryllus sagani sp. nov.: (A) male forewing in dorsal view, (B) female forewing in dorsal view, (C–E) scanning electron micrograph of the stridulatory teeth. Scale bars: A, B, 5 mm; C, 100 μm; D–E, 10 μm.

FIGURE 5. Genitalia of Indigryllus sagani sp. nov.: male genitalia in ventral (A), dorsal (C), lateral (D) and postero-ventral (E) views; comparison with I. kudremu in ventral view (B); female copulatory papilla of Indigryllus sagani sp. nov. in dorsal (F) and ventral (G) views. Scale bars: A–E, 1 mm; F–G, 0.5 mm.

FIGURE 6. Indigryllus sagani sp. nov.: male of light morph (A–B) and female of dark morph (C–D) in dorsal and lateral views, respectively. Scale bar: 5 mm.

FIGURE 7. Indigryllus sagani sp. nov.: females of dark morph in their natural habitat.

FIGURE 8. Indigryllus sagani sp. nov.: male specimens of light morph (B, D) and dark morph (A, C) in their natural habitat; (B–D) showing wing positions while male is calling.

FIGURE 9. Indigryllus sagani sp. nov.: natural habitat in type locality.

FIGURE 10. Calling song of Indigryllus sagani sp. nov.: (A) oscillograms of 10 echemes grouped in doublets, (B) detailed oscillogram of one echeme and (C) corresponding spectrogram; (D) frequency spectrum showing harmonic frequencies.