Trellius (Protrellius) neesoon Gorochov et Tan

Gorochov, Andrej V. & Tan, Ming Kai, 2012, New crickets of the subfamilies Phaloriinae and Pteroplistinae (Orthoptera: Gryllidae) from Singapore, Zootaxa 3525, pp. 18-34 : 19-21

Trellius (Protrellius) neesoon Gorochov et Tan , new species

( Figs 1–6 , 7, 8 , 17, 18 )

Material examined. Holotype (male): Singapore, Central Catchment Nature Reserve, Nee Soon pipeline, secondary forest, near primary swamp forest, 20 April 2011, coll. M.K. Tan & M.R.B. Ismail.

Paratypes: Singapore: 1 male, Bukit Timah Nature Reserve, degraded hill forest, 25 July 1967, coll. D.H. Murphy; 1 male, same reserve, Jungle Fall Valley, along stream in secondary forest, 18 July 1979, coll. D.H. Murphy; 1 male, MacRitchie Catchment Area, Sime Road forest, under log, 4 April 1975, coll. D.H. Murphy; 1 male, labelled “new road by racecourse”, actual locality unknown but suspect to be along Old Upper Thomson Road bordering Central Catchment Nature Reserve, under bark of felled trees, 25 April 1976, coll. D.H. Murphy.

Diagnosis. The new species is most similar to Trellius curup Gorochov from Sumatra ( Gorochov, 2010), but distinguished from it by the distinctly shorter dorsal lobules of epiphallus. From all the other species of this subgenus, the new species differs in the presence of short dorsal epiphallic lobules (versus absence of dorsal epiphallic lobules or presence of long spine-like processes instead them) in combination with the lateral epiphallic processes longer and/or narrower, additional processes and spinules on these processes absent, ectoparameres and guiding rod small, and distal part of this rod spine-like.

Description. Male holotype. General appearance typical of this genus ( Fig. 1 ). Head with frontal rostrum between antennal cavities approximately as wide as scape. Pronotum moderately transverse (1.3 times wider than long), weakly widening posteriorly ( Fig. 1 ). Fore tibiae with rather large, oval tympana on both side; inner tympanum slightly larger than outer one and hardly immersed ( Fig. 7 ); hind tibiae with 4 pairs of long movable dorsal spines (length of longest inner distal spine 2.6 mm), not very numerous small immovable spinules between them, and 6 long spurs (=apical spines) (length of longest inner dorsal spur 2.3 mm).

Tegmina reaching distal third of hind femora, with 7 oblique veins (2 proximal veins small) in dorsal field; mirror with 2 dividing veins gently converging medially ( Fig. 2 ); lateral tegminal field with 18 branches of Sc and 9 crossveins between R and M ( Fig. 2 ); stridulatory vein of right tegmen short and sinuous as shown in Fig. 3 , and with 19 stridulatory teeth; hind wings distinctly exposed behind tegmina. Anal (=supra-anal) plate of abdomen simple but with median groove, lateral ridge, and apex truncate; subgenital plate rectangular (longer than wide), with apical part truncate and with median groove, as well as with shallow depression on distal half (as in Fig. 8 ).

Genitalia ( Figs 4–6 , 17, 18 ): each posterolateral part of epiphallus with rather short ventral spine, long lateral process directed backwards and having narrowly rounded apex, two dorsal lobules (one directed backwards and slightly bilobate at apex, and one directed partly medially and with rounded apex), and medial ribbon almost reaching small median sclerite of epiphallus; last sclerite with rather wide lateral apodemes and small posteromedian spine; ectoparameres small and with rather thin posterior part; endoparameres with posterolateral arms fused with ectoparameres, wide (long) median bridge, and rather short anterior apodemes; guiding rod rather small, with oval plate-like proximal part and with spine-like distal part situated just under posteromedian spine of median epiphallic sclerite; mold of spermatophore attachment plate not wide, but its apodeme long and directed backwards ( Fig. 4 ).

Colouration. Brown with following marks: head with dark patterns on vertex, with median and lateral ocelli white, and with mouthparts light brown; fore and middle femora light brown with 2 brown bands (one near middle, and one near knee); fore and middle tibiae with 2 whitish bands (one just below tympanum, and one near apex); hind tibiae with numerous light brown bands (some of which situated between spurs); tegminal lateral field with membranes between R and M light yellowish brown, and with membranes between Sc branches transparent; abdomen with cerci light brown.

Variations. Right tegmina of paratypes with 6–7 oblique veins (2 proximal veins small) in dorsal field; lateral tegminal field with 18–20 branches of Sc and 8–9 crossveins between R and M.

Female. Unknown.

Measurements. See Table 1 .

Etymology. The species is named after type locality, environs of Nee Soon pipeline. Nee Soon pipeline refers to a trail within the Central Catchment Nature Reserve, which is located adjacent to Singapore’s remaining primary freshwater swamp.

Figures

FIGURES 1 – 6. Trellius neesoon sp. n. (Phaloriinae), male holotype: 1, general view from above; 2, right tegmen; 3, stridulatory vein of right tegmen from below; 4 – 6, genitalia and mold of spermatophore attachment plate (different photographs combined) from above (4); genitalia without this mold from below (5) and from side (6). Scale bars 5 mm for FIGURES 1, 2; 1 mm for Fig 3.

FIGURES 7 – 16. Phaloriinae and Pteroplistinae (schematically): 7, 8, Trellius neesoon sp. n. (7, holotype; 8, paratype); 9, 10, Tremellia timah sp. n. (9, paratype; 10, holotype); 11, 12, Phaloria? jerelynae sp. n., holotype; 13 – 16, Singapuriola separata sp. n., paratypes. Inner side of fore tibia (7, 9, 11, 13); male subgenital plate from below (8, 10, 12, 14); female subgenital plate with base of ovipositor from below (15); ovipositor from side (16). Scale bars 1 mm.

FIGURES 17 – 24. Phaloriinae and Pteroplistinae, male (schematically): 17, 18, Trellius neesoon sp. n., holotype; 19, 20, Phaloria? jerelynae sp. n., paratype; 21 – 23, Singapuriola separata sp. n., paratype; 24, Tremellia timah sp. n., holotype. Genitalia from above (17, 19, 21) and from below (18, 20, 22); mold of spermatophore attachment plate from behind and slightly above (23); ectoparamere from below (24).

Tables

TABLE 1. Measurements of Trellius (Protrellius) neesoon (in mm, mean values in brackets).

	BL	BWL	PL	PW	TL	TW	HFL	HTL
Male holotype	13.5	24.2	2.9	3.9	17.4	-	11.7	11.5
Male paratype 25 Jul.1967	13.0	22.7	2.8	4.0	15.2	6.0	11.3	11.1
Male paratype 4 Apr.1975	12.5	23.1	3.0	4.1	16.9	-	12.2	11.8
Male paratype 25 Apr.1976	13.3	23.5	2.9	4.0	16.0	6.6	11.8	-
Male paratype 18 Jul.1979	12.4	23.3	2.9	3.6	15.6	6.2	11.1	10.8
Males (n = 5)	12.4–13.5 (12.9)	22.7–24.2 (23.4)	2.8–3.0 (2.9)	3.6–4.1 (3.9)	15.2–17.4 (16.2)	6.0–6.6	11.1–12.2 (11.6)	10.8–11.8