Rhicnogryllus bipunctatus Ingrisch, 1987

Tan, Ming Kai, Baroga-Barbecho, Jessica B., Japir, Razy, Chung, Arthur Y. C., Wahab, Rodzay Bin Haji Abdul & Yap, Sheryl A., 2020, A taxonomic study on the Bornean and Philippines Sword-tailed Crickets in the genus Rhicnogryllus Chopard, 1925 (Orthoptera: Trgonidiidae; Trigonidiinae), Zootaxa 4763 (2), pp. 217-230 : 222-224

Rhicnogryllus bipunctatus Ingrisch, 1987

Figs. 3 , 6

Rhicnogryllus bipunctatus — Ingrisch, 1987: 176 > original description; Tan et al., 2019c: 306 (record in Sandakan) Rhicnogryllus eximius —Chopard, in litt.

Material examined. Male holotype (only images examined), East Malaysia, Sarawak, Batu Niah, 3/4 August

1984, coll. S. Ingrisch ( SMFD). Paratype of Rhicnogryllus eximius (1 male, MNHN-EO-ENSIF6583, only images examined), East Malaysia, Sabah (“North Borneo”), Sandakan, 24 July 1927 ( MNHN).

1 female (BRU.19.61), Brunei Darussalam, Belait District, Teraja, N4.28487, E114.41817, 28.7±74.9 m.a.s.l., 1906 hours, 2 March 2019, coll. M. K. Tan & H. Yeo; 1 male (BRU.19.68) and 1 female (BRU.19.69), same locality, Wasai Wong Kadir Recreational Park, N4.3421, E114.44655, 23.0± 6.6 m.a.s.l., 1639 hours, 7 July 2019, coll. M. K. Tan & H. Yeo ( ZRC and UBDM).

4 males (SDK.19.42–45), East Malaysia, Sabah, Sandakan, Ulu Dusun, N5.78364 –5.78379, E117.76051 – 117.76094, 38.3–41.6± 5.1–6.7 m.a.s.l., 1008–1038 hours, 10 January 2019, coll. M. K. Tan, R. Japir, M. Binti & J. L. Yukang; 1 female (SDK.19.67), same locality, Sepilok, Rainforest Discovery Centre, N5.87575, E117.94059, 54.5± 6.3 m.a.s.l., 0946 hours, 1 October 2019, coll. M. K. Tan & J. L. Yukang ( ZRC and FRC).

Type details. Male holotype, Borneo: Sarawak: Batu Niah ( SMFD)

Remarks. A male “ paratype ” of Rhicnogryllus eximius Chopard collected from Sandakan was found in MNHN and it resembles R. bipunctatus as described by Ingrisch (1987) as well as the recent specimens collected from Brunei and Sandakan. However, we could not find any publication of the description associated with R. eximius and concluded that Chopard may not have described this species despite specifying the type specimens until Ingrisch (1987) described the exact same species from Sarawak. Thus, we consider Chopard’s R. eximius as a synonym of R. bipunctatus .

Ingrisch (1987) provided a comprehensive description of the male, but the female was not known at that time.

Diagnosis. This species differs from congeners by the combination of these characters: generally black colouration, with dorsum of head with a broad white line connecting the eyes; antennal scapus red brown; posterior femora white with two black bands, posterior tibia red brown; tarsal segments whitish; tegmen with a big, round, white spot at the base; supra-anal plate and base of cerci white; and male genitalia ( Fig. 3 ). The male genitalia is also similar to that of Trigonidium but differs by virga as long as rachis (usually shorter than rachis in Trigonidium ).

Distribution. Borneo: Sandakan (Sabah); Batu Niah ( Sarawak); Brunei Darussalam

Male genitalia characteristics ( Figs. 6 A–C). Pseudepiphallus separated into two lateral parts joined by an anterior sclerotized bridge; bridge narrow and gently curved. Posterior apex of pseudepiphallus forming thin and long, sclerotized lophi; lophus feebly curved inwards, with inner margin with 4–5 tooth-like spines, with apex forming a tooth; posterior edges of pseudepiphallic sclerite with a stout, angular lobule in the middle, lobule with stout teeth along margin. Pseudepiphallic parameres elongated heart-shaped, not exceeding apex of pseudepiphallic lobules. Ectophallic fold large forming an elongated sclerotized virga with acute apex. Ectophallic apodeme weakly sclerotized but long. Ramus straight. Endophallic sclerite elongated along dorsal cavity, with a median crest, with lamella of apodemes appearing flat and broad.

Female description. Habitus similar to males, does not exhibit sexual dimorphism. Supra-anal plate with basal half black, with a longitudinal groove and angularly emarginated at the apex; epiproct with broad and stout, with obtuse apex, white. Subgenital plate stout, distinctly broader than wide, with anterior margin straight, apex narrowly excised in the middle; basal part black, thereafter white. Ovipositor not surpassing cerci; basal third with margins straight and smooth; apical third with dorsal margin distinctly denticulated, ventral margin also denticulated but less dense and only towards the apex. Ventral valves slightly longer than dorsal valves.

Natural history. This species tends to be found among foliage of shrubs or low-lying vegetation in the understory of relatively disturbed forest and/or forest edge (at least in Sandakan and Brunei). Ulu Dusun and Rainforest Discovery Centre (Sandakan) as well as Teraja and Wasai Wong Kadir Recreational Park ( Brunei) typically are disturbed forest with the presence of human traffic. The species can be found active in both day and night.

Figures

FIGURE 3. Live habitus of Rhicnogryllus bipunctatus female from Sandakan, Sabah (locality of R. eximius sensu Chopard) (A) and male from Brunei Darussalam (B).

FIGURE 6. Male genitalia of Rhicnogryllus bipunctatus (A–C) and Rhicnogryllus paetensis n. sp. (D–F) in dorsal (A, D), ventral (B, E) and lateral (C, F) views.