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.