Description of three new species of predatory Genus Hexacentrus (Orthoptera Tettigoniidae) from India, with bioacoustic and morphological characterizations Author Ghosh, Aarini 0000-0003-4705-9846 Department of Biology, Ashoka University, Sonipat, Haryana, 131029, India. & https: // orcid. org / 0000 - 0003 - 4705 - 9846 Author Jaiswara, Ranjana 0000-0002-2672-3093 Department of Zoology, Panjab University, Chandigarh, 160014, India. & https: // orcid. org / 0000 - 0002 - 2672 - 3093 Author Sabharwal, Shagun 0000-0001-8828-5781 School of Biological Science, NISER, Orissa, 752050, India. & https: // orcid. org / 0000 - 0001 - 8828 - 5781 Author Dasoju, Vivek 0000-0003-3815-9255 Department of Psychology, Ashoka University, Sonipat, Haryana, 131029, India. & https: // orcid. org / 0000 - 0003 - 3815 - 9255 Author Bhattacharjee, Anubhab 0000-0002-1088-7157 Department of Biology, Ashoka University, Sonipat, Haryana, 131029, India. & https: // orcid. org / 0000 - 0002 - 1088 - 7157 Author Rajaraman, Bittu Kaveri 0000-0003-2435-7015 Department of Biology, Ashoka University, Sonipat, Haryana, 131029, India. & Department of Psychology, Ashoka University, Sonipat, Haryana, 131029, India. & https: // orcid. org / 0000 - 0003 - 2435 - 7015 text Zootaxa 2023 2023-03-02 5249 3 335 356 http://dx.doi.org/10.11646/zootaxa.5249.3.2 journal article 10.11646/zootaxa.5249.3.2 1175-5326 7690993 51EE6A05-41C8-44F7-90C9-B785D6788E1B Hexacentrus khasiensis Ghosh, Jaiswara & Rajaraman sp. nov. Type material. Holotype , J, INDIA : Meghalaya , East Khasi Hills , Shillong , ~ 1400 m a.s.l. , 01.IX.2021 , 25° 36’ 59.76” N ; 91° 54’ 2.52” E , AG_SH1_M6 ( ZSI ) . Allotype , , AG_SH1_F1, same locality as holotype ( ZSI ) . Paratypes (4 J , 3 ), same information as holotype , VIII–IX.2021 : 2 J ( AG _ SH1 _M1, AG_SH1_M2) 2 J ex-AG_ SH1_M3 ( BNHS ) , ex-AG_SH1_M4 ( BNHS ); 2 ( AG _ SH1 _F2, AG_SH1_F3), 1 ex-AG_SH1_F4 ( BNHS ) . Type locality. East Khasi Hill , Shillong , Meghalaya , India ( Fig. 1 ) . Distribution. In addition to type locality, this new species has been heard in different parts of the Khasi hills including the Ri-Bhoi and West Khasi Hill districts of Meghalaya . The same call type has been recorded in Balpakram National Park in the South Garo hill district of Meghalaya ( Fig.1 ). Etymology . The species is named after the type locality Khasi hill of Meghalaya . Diagnosis. The species is somewhat similar to H. formosanus Chen & He, 2021 with respect to the marks on the disc of pronotum however it differs as follows: In H. formosanus the lateral margin of the pronotum is straight but in H. khasiensis sp. nov. it is slightly concave. Teeth in the middle region of the stridulatory file in H. khasiensis sp. nov. are much wider than the lateral teeth. Stridulatory teeth are more in number in H. khasiensis sp. nov . Apical third of cerci in H. khasiensis sp. nov. longer and styli narrower. Female ovipositor is much narrower. Description. Male . Body medium sized and slender ( Fig. 3A–B ). Head. Fastigium verticis triangular, narrow, laterally compressed with median longitudinal sulcus. Apex narrow, tapering forward, rounded in lateral view ( Fig. 3C ). Base of fastigium 1.25 times as wide as scapus. Fastigium verticis separated from fastigium frontis by a furrow. Eyes globular. Pronotum. Saddle-shaped, longer than broad, and expanded posteriorly. Anterior margin straight. Posterior margin slightly concave and the pronotal disc flat expanded and rounded in posterior region ( Fig. 3C ). An hourglass-like band covers whole pronotum. Median carina faintly visible. Slightly depressed behind first transverse sulcus; with three transverse sulci. A ‘V-shaped sulcus is present between first and second sulci ( Fig. 3C ). Second and third transverse sulci restricted to disk. Ventral margin of the lateral lobe inclined downwards longer than high, humeral sinus absent. Anterior angle obtuse, and posterior angle rounded. Posterior part forming a straight slope, and anterior part straight ( Fig. 3E ). Thoracic auditory spiracle large and oval, party hidden under lateral lobe of pronotum. Legs. Fore coxae with a forward outward projecting spine. FI dorsally unarmed and ventrally armed with 3–4 subapical spurs present on inner margin with 4–5 spines present in between subapical spurs and outer margin bearing 4–9 spines, no subapical spurs. TI armed with 6 long subapical spurs, first subapical spur slightly shorter than 2 nd subapical spur and then decreasing in length apically on both sides. TII armed with 6 subapical spurs on inner and outer margins. TIII dorsally armed with 22–34 spines on the inner margin and 20–33 spines on outer margin, ventrally armed with 11–15 and 10–13 subapical spurs variable in length on outer and inner margin. FIGURE 3. Hexacentrus khasiensis male: (A–B) Dorsal and Lateral view. Scale 5mm, (C) Dorsal view of head and pronotum. Scale 5mm, (D) Supra-anal plate, (E) Lateral view of head and pronotum. Scale 5mm, (F–G) Dorsal and Lateral view of subgenital plate, Scale 1mm. FIGURE 4. Hexacentrus khasiensis female: (A–B) Dorsal and Lateral view. Scale 5mm, (C) Dorsal view of head and pronotum, (D) Ventral view of Specimen, (E) Face, (F) Maxillary palpi. Scale 1mm, (G) Lateral view of head and pronotum, (H) Dorsal view of the subgenital plate. Scale 1mm, (I) Ovipositor in lateral view, (J) Supra-anal plate. Scale 1mm. Male. Tegmen of medium size, broad in the middle, apical margin not oval in lateral view ( Fig. 3B ), reaching middle of hind tibia. Left tegmen long, stridulatory file with 37–40 teeth; 1 st anal vein teeth broader and elevated, followed by narrow teeth. Mirror longer than wide. Media slightly curved, Cubitus posterior vein slightly bent in middle, space between CuP and CuA slightly wider than M and CuA, 1 st anal vein bearing stridulatory file inclined, 1.3 mm long with 37–40 teeth ( Fig. 14A ). Male. Genitalia. Supra-anal plate triangular with a dorsal groove, apex round. Cerci long cylindrical, then slowly narrowing to a long digitiform apical appendage with incurved apex ( Fig. 3D ). Subgenital plate elongate with a median longitudinal furrow, lateral ridges well developed, apical margin with deeply curved ( Fig. 3F ). Female. Small body. Pronotum . Lateral lobe straight in posterior margin ( Fig. 4F ). Wings . FW narrow and short, reaching mid ovipositor ( Fig. 4B ). Female Genitalia . Supra-anal plate triangular with dorsal groove, short in length and broad basally, apex rounded ( Fig. 4H ). Cerci conical, slightly upcurved, and apex diverging. The subgenital plate is triangular and wide ( Fig. 4J ). Apex with a median excision. Ovipositor broad at the base, straight, and with pointed end ( Fig. 4I ). Coloration . Green when alive ( Fig. 2B&D ). Antennae with regularly spaced blackish brown annules. Male FW with stridulatory apparatus and apical field rusty brown. The dorsal part of the female FW is rusty brown. TABLE 2. Measurements of male and female H. khasiensis Ghosh, Jaiswara & Rajaraman sp. nov. Abbreviations listed in material and method section. Values in mm.
Males FW_L BL_FWL PH PL FI_L TI_L FIII_L TIII_L
Holotype 21.4 30 2.9 6.5 6.5 7.3 17.4 17.3
M_1 paratype dry 21.3 30 4 6.4 6.7 5.7 15.8 15.2
M_2 paratype dry 21.5 32 3.9 6.5 6.5 7.5 16 17
M_3 paratype wet 21.3 31 3.1 6.3 6.3 8 15.7 17.3
M_4 paratype wet 23.4 35 3.7 7 6.3 7.8 17.8 17.8
Continued.
Females BL FW_L Ovi_L PH PL FI_L TI_L FIII_L TIII_L
Allotype 25.3 19.4 14 3.5 5.4 6.9 7.6 17.3 18.5
F_1 paratype dry 23.5 20 11.32 4.4 5.2 6.8 8.7 18 18.3
F_2 paratype wet 26.5 20.2 14.3 3.2 5.3 6.4 7.1 17 17.4
F_3 paratype wet 22.8 19.5 13.6 3.9 5.5 4.2 4.8 9.9 11
Acoustic measurements. The continuous call of Hexacentrus khasiensis consists of a broadband trill alternating with an amplitude modulated trill ( Fig. 6A ). All measurements were made for at least 10 syllables per call portion per animal, for multiple animals. In the field, it sounds as if two different individuals are calling because of the continuous droning sound produced by opening and closing of the wing, but recordings in the lab verified that the call was produced by a singular individual.