Hexacentrus ( Serville 1831 )

Tiwari, Chandranshu & Diwakar, Swati, 2024, The Orchestra Nocturne: Description For Six New Katydid Species From India (Orthoptera: Tettigoniidae), Zootaxa 5405 (2), pp. 227-245 : 228-229

Key to species of Hexacentrus ( Serville 1831) from India

1. Prosternum and Mesosternum unicolor, femora in the general coloration.......................................... 2

- Prosternum and Mesosternum blackish brown, femora brownish at apex.......................................... 3

2. Mirror on the tegmen rhomoboid in shape, body yellowish green, third and fourth joint of tarsi blackish brown ( Wang and Shi 2005: Fig 1 , 4 )................................................................. H. expansus (Wang and Shi)

- Mirror on the tegmen oviform........................................................................... 4

3. Antennae concolorous, Male tegmen with angular apex....................................................... 5

- Antennae discolorous, Male tegmen rounded at apex......................................................... 6

4. Male tegmen inflated.................................................................................. 7

- Male tegmen not inflated............................................................................... 8

5. Fore femora armed with 5–6 ventral spines on the inner margin, stridulatory file with 32 teeth, subgenital plate with styles curved and converging apically ( Farooqi and Usmani 2018b: Fig 7I ; 8A.............. H . bifurcatus (Farooqi and Usmani)

- Fore femora armed with 18–30 ventral spines on inner and outer margin, stridulatory file with 20–23 teeth, styles diverging from each other ( Ghosh et al. 2023: Fig 11 A–D, 12)....................................... H. tiddae (Ghosh et al.)

6. Hind wings are shorter and hidden under tegmen, stridulatory file with 37–40 teeth with 4 large teeth in the middle ( Ghosh et al. 2023: Fig 3A–B , 5 )........................................................... H. khasiensis (Ghosh et al.)

- Hind wings same size or larger than tegmen, stridulatory file homogenous with 40 teeth ( Ghosh et al. 2023: Fig 7 A–B , 9)................................................................................... H. ashoka (Ghosh et al.)

7. Stridulatory file homogenous, Ovipositor straight, base thickened ( Ingrisch and Shishodia 2000: Fig 143–144)............................................................................................ H. major (Redtenbacher)

- Stridulatory file with 2–3 large teeth, ovipositor curved, rather longer than the body................ H. mundus (Walker)

8. Male tegmen short and broad, stridualtory file moderately sulcate with <30 teeth and with>3 large teeth................ 9

- Male tegmen long and narrow, stridulatory file moderately sulcate with>30 teeth and 3 large teeth at the distal end ( Farooqi and Usmani 2018b: Fig 1 ; Inagaki et al. 1990: Fig B,D)...................................... H. unicolor (Serville)

9. Stridulatory file with 5 large teeth towards the distal end, Subgenital plate long with elongated, wide, longitudinal median furrow, lateral ridges well developed, apical margin with rounded excision; styles straight, diverging apically, chirping call ( Inagaki et al. 1990 Fig A, B; Farroqi and Usmani 2018b: Fig 4I )............................... H. japonicus (Karny)

- Stridulatory file with 4 large teeth in the middle, Subgenital plate long with elongated, wide, longitudinal median furrow, lateral ridges well developed, apical margin with rounded excision; with styles curved, converging apically, buzzing call ( Fig 1G, 1I ).................................................................................... H. sylvanus sp. nov

Figures

FIGURE 1. Hexacentrus sylvanus (a) habitus, (b) dorsal view of head, (c) laterial view of head, (d) face, (e) lateral view of head and pronotum (f) ventral view of right tegmen (P: Plectrum, M: Mirror), (g) ventral view of subgenital plate (h) lateral view of cercus, (i) scanning electron microscope image of stridulatory file.

FIGURE 3. P. midoriyae (a)–(b) scanning electron microscope image of stridulatory file.

FIGURE 4. Euconocephalus helleri (a) habitus, (b) dorsal view of fastigium, (c) dorsal view of pronotum, (d) ventral view of sternum, (e) lateral view of abdomen and cerci (f) dorsal view of right tegmen, (g) supra-anal plate, (h) subgenital plate, (i) scanning electron microscope image of stridulatory file.

FIGURE 5. Euconocephalus malabaricum (a) habitus, (b) dorsal view of head depicting fastigium, head and pronotum, (c) lateral view of head with notched frons, (d) ventral view of sternum, (e) ventral view of left tegmen with stridulatory file, (f) ventral view of right tegmen, (g) subgenital plate, (h) supra-anal plate, (i) wing apex.

FIGURE 7. Euconocephalus latipennis (a) habitus, (b) dorsal view of head depicting fastigium, head and pronotum, (c) lateral view of head with notched frons, (d) ventral view of sternum, (e) wing apex (f) dorsal view of right tegmen, (g) subgenital plate, (h) lateral view of male cercus, (i) scanning electron microscope image of stridulatory file.

FIGURE 8. Euconocephalus brevicornis (a)–(b) habitus in different color morphs, (c) dorsal view of head depicting fastigium, head and pronotum, (d) face, (e) lateral view of head with notched frons, (f) ventral view of sternum (g) lateral view of cercus, (h) dorsal view of right tegmen, (i) supra-anal plate, (j) subgenital plate, (i) scanning electron microscope image of stridulatory file.