Ducetia rohinii Tiwari and Diwakar, 2023

Tiwari, Chandranshu & Diwakar, Swati, 2023, Description of two new species of the Genus Ducetia Stål 1874 (Orthoptera: Tettigoniidae: Phaneropterinae) from India, Zootaxa 5296 (2), pp. 292-300 : 297-299

Ducetia rohinii Tiwari and Diwakar sp. n.

( Fig. 4–5 , Table 2 )

Material examined. Holotype: Male. INDIA, Goa, Bhagwan Mahavir Wildlife Sanctuary, 2016, ~ 840 m a.s.l. Coll. Chandranshu Tiwari, Department of Environmental Studies, University of Delhi, 110007 (Delhi), India . Paratype: Goa, Bhagwan Mahavir Wildlife Sanctuary , 2016, ~ 840 m a.s.l. Coll. Chandranshu Tiwari, 2020 (2 ♁).

Type locality. Bhagwan Mahavir Wildlife Sanctuary , South Goa, Goa, India.

Measurements (length in mm). Body 19.6 (2.3); tegmen 28.24 (2.07); pronotum 4.55 (0.49); pro-femur 7.17 (0.32); meso-femur 10.32 (0.82); post-femur 22.43 (1.22); pro-tibia 7.33 (1.28); meso-tibia 10.09 (0.7); post-tibia 24.66 (1.01); file 1.42 (0.10).

Distribution. Crepescular. Found only in undisturbed bushes and, forest understorey. At present only known from the type locality but likely to be distributed in Western Ghats.

Seasonal Occurrence. The species was recorded during the dry season following the monsoon.

Etymology. This species epithet is in recognition of Prof. Rohini Balakrishnan , who laid the foundation for Orthopteran bioacoustics in India.

Differential diagnosis. The species is similar to D. malayana ( Heller 2017) but differs in smaller body size and smaller subgenital lobes. D. rohinii exhibited a longer tegmina compared to D. malayana despite the smaller body. D. rohinii had a significantly denser stridulatory comb compared to D. malayana . The two species produced a similar call pattern, however D. rohinii lacked the isolated syllables produced by D. malayana ( Heller et al. 2017; Tiwari and Diwakar 2023).

Description.

Male. Medium size and slender bodied. Head. Fastigium verticis narrow conical, dorsally furrowed, apex subacute, separated from fastigium frontis by a rectangular step. Eye ovoid, slightly bulging. Pronotum with disc rounded into paranota, only apical area flat and shouldered. Legs. Anterior coxa with a small spine. Anterior femur slightly compressed. Geniculaer lobes of all legs bispinose. Tibial tympana open on both sides. Femora with following number of spines on ventral margins: profemur 5–6 internal, 8–9 external; mesofemur 1 internal, 10–11 external; posterior femur 8–9 external, no internal. Pro- and mesotibia with 2 and 4 apical spurs respectively and following number of spines: protibia 8–9 ventro-internal, 13–14 ventro-external, 5–6 dorso-internal, 8–9 dorso external; mesotibia 14–15 ventro-internal, 7–8 ventro-external, 7–8 dorso-internal, 7–8 dorso-external. Posterior tibia with 6 apical spurs, 25–27 ventro-internal, 22–23 ventro-external, 35–37 dorso-internal, 38 dorso-external. Wings. Tegmina surpassing hind knee; radius sector branching pectinately before middle of tegmina. Hind wings caudate. Stridulatory file with 138±2 teeth (n=3), which are large and spaced in basal half, gradually becoming narrower and denser towards the apex.

Male genitalia. Subgenital plate for most of its length divided into two, little curved, parallel lobes provided along inner margins with numerous minute teeth. Distal lobes contiguous. Cerci long, slender, feebly directed upwards with interno-ventral ridge.

Female: Unknown. Supposed to be similar to that of D. malayana .

Coloration: Green and brown color morphs. Males with a narrow brown medial band starting from head continuing to disc of pronotum and dorsal margin of tegmen. Tegmen with little conspicuous black dots in cells. Antennae pale brown, annulated. Pro- and mid femora brown; posterior femora green with dark dots on dorsal areas, anterior tibia tympanum yellowish brown. Tibial segment brown-black in green morphs and yellow in brown morphs respectively. Tegmen appears green when alive, but is hyaline with veins and veinlets brown. Stridulatory vein brown with brownish file, cerci darkened towards tip.

Depositories. The specimen are deposited in the Department of Environmental Studies, Faculty of Science, University of Delhi.

Figures

FIGURE 4. Ducetia rohinii sp. nov. Habitus (a) male, (b) female and Call pattern (c) spectrogram, (d) oscillogram.

FIGURE 5. D. rohinii sp. nov. (a) pronotum depicting Plectrum (P) and Mirror (M); (b) stridulatory file (c) lateral view of cercus; (d) ventral view of subgenital plate; (e) scanning electron microscope image of stridulatory file.