Trilacuna rastrum Tong & Li, 2007

Trilacuna differs from other oonopid genera, except those of the “Dysderoides complex” (including Bannana Tong & Li, 2015, Dysderoides Fage, 1946, Himalayana Grismado, 2014, and Trilacuna), by the enlarged male palpal femur, the very complex embolus-conductor system, and the notched labium. Males differ from the other genera of the “Dysderoides complex” by usually lacking the furrow connecting the posterior tracheal spiracles, and females differ by having a long postgastric scutum covering almost the whole ventral abdomen (Grismado et al. 2014; Tong et al. 2019).

34 species, including four described here.

Iran to the Korean Peninsula.

3♂1♀, Myanmar, near 1.5 km from the roadside between Kanpetlet and Nat Ma Taung National Park; 21°13.058'N, 93°59.033'E; elevation ca 2420 m; 1.V.2017; Wu J. and Chen Z. leg. (IZCAS AR-25151-25152-25153-25154).

Figure 1. 

Trilacuna besucheti, male (IZCAS AR-25151) A–C habitus in dorsal, ventral, and lateral views D–F, H prosoma in dorsal, ventral, lateral, and anterior views G labium and endites in ventral view. Abbreviations: boc = booklung covers; bts = bent thick setae; cmp = clypeus median projection; esb = elevated seta base; ldi = labium deep incision. Scale bars: 0.4 mm (A–F, H); 0.2 mm (G).

Males of this species can be recognized by the circular, scale-like structure on the distal part of the bulb (white arrows in Fig. 2E, F) and the cymbium, which has two or three stout, dark setae with large bases (black arrows in Fig. 2G). Females are distinguished by having a darkened band (db) on the posterior margin of the epigastric furrow (Figs 3G, 15A).

Figure 2. 

Trilacuna besucheti, left male palp, SEM (IZCAS AR-25151) A, B, H prolateral, retrolateral, and dorsal views C, D palpal bulb in prolateral and retrolateral views E, F, I distal part of palpal bulb in prolateral, retrolateral, and dorsal views (white arrows show the circular scale-like structure) G cymbium in prolateral view (black arrows show the large setae bases). Abbreviations: ab = anterior branch; emb = embolus; lb = lateral branch; ls = long setae.

See Grismado et al. (2014).

The specimens from Myanmar have unbranched endites (Fig. 16E, F) and a strongly striated carapace (Figs 1D, F, 3D, F), whereas the specimens from India have distinctly branched endites and a smooth carapace (Grismado et al. 2014: figs 32–34).

India (Meghalaya), Myanmar.

Figure 3. 

Trilacuna besucheti, female (IZCAS AR-25154) A–C habitus in dorsal, ventral, and lateral views D–F prosoma in dorsal, ventral, and lateral views G abdomen in ventral view. Abbreviation: db = darkened band; ldi = labium deep incision. Scale bars: 0.4 mm.

Holotype ♂: Myanmar, near 1.5 km from the roadside between Kanpetlet and Nat Ma Taung National Park; 21°13.058'N, 93°59.033'E; elevation ca 2420 m; 1.V.2017; Wu J. and Chen Z. leg. (IZCAS AR-25139). Paratype 1♀: Myanmar, same data as for holotype (IZCAS AR-25140).

The new species is similar to T. mahanadi Grismado & Piacentini, 2014 but can be distinguished by the long, strongly curved spines on the male endites (Figs 4G, 16A, B), the bare dorsal branch (db) of the embolus system (Figs 5E, F, H, 14E), and the triangular plate (tp) of the female epigastric area (Fig. 6G). The male of T. mahanadi has unmodified endites and lacks the dorsal branch of the embolus system, and the triangular plate is lacking in the epigastric area of the female (Grismado et al. 2014: figs 36–38).

Figure 4. 

Trilacuna changzi sp. nov., male holotype A–C habitus in dorsal, lateral, and ventral views; black arrow shows the cluster of densely, short setae D–F, H, I prosoma in dorsal, lateral, ventral, posterior, and anterior views G labium and endites in ventral view; white arrow shows the long, strongly curved spines. Abbreviations: boc = booklung covers; cmp = clypeus median projection; esb = elevated seta base; ldi = labium deep incision. Scale bars: 0.4 mm (A–F, H, I); 0.2 mm (G).

Male. Body: yellow-brown, chelicerae and sternum lighter, legs yellow; habitus as in Figure 4A–C; body length 1.56. Carapace: 0.76 long, 0.64 wide; sides smooth, lateral margin rebordered (Fig. 4D); posterior surface with several large setal bases (Fig. 4H). Eyes: ALE largest; PLE and PME nearly equal in size; ALE–PLE separated by less than ALE radius; PME touching each other; posterior eye row recurved as viewed from above, procurved as viewed from front (Fig. 4D, I). Clypeus: height about 0.7 times of ALE diameter, with a triangular, pointed median projection (cmp). Mouthparts (Figs 4G–I, 16A, B): endites slender, with two long, strongly curved spines. Sternum: (Fig. 4F). Abdomen: 0.82 long, 0.66 wide; booklung covers ovoid, surface smooth (Fig. 4I); dorsal scutum not fused to epigastric scutum; apodemes present, posterior spiracles not connected by groove; epigastric region with a cluster of dense, short setae (Fig. 4C). Palp (Figs 5, 14D–F): orange; 0.48 long (0.15, 0.11, 0.09, 0.13); femur greatly elongated (width/length = 0.65) (Fig. 5A, B); bulb pear-shaped, tapering apically; embolus system (Fig. 5E, F, H) with a bare dorsal branch (db) in prolateral view, and a small median branch (mb) and laterally curved branch (lb) in dorsal view.

Figure 5. 

Trilacuna changzi sp. nov., male holotype, left palp A, B, G prolateral, retrolateral, and dorsal views C, D palpal bulb in prolateral and retrolateral views E, F, H distal part of palpal bulb in prolateral, retrolateral and dorsal views. Abbreviations: db = dorsal branch; emb = embolus; lb = lateral branch; mb = median branch; vs = ventral setae.

Female. Same as male except as noted. Habitus: as in Figure 6A–C; slightly larger than male. Body: length 1.76. Carapace: 0.79 long, 0.67 wide. Abdomen: 1.12 long, 0.82 wide. Endites: unmodified. Epigastric area (Figs 6G, 15C): with a large, triangular plate (tp). Endogyne (Fig. 15D): with narrow, transverse sclerite (tsc), an anterior stick-shaped sclerite (as), and a posterior tortuous, tube-like globular structure (glo); transverse bars (tba) with two lateral apodemes (ap).

Figure 6. 

Trilacuna changzi sp. nov., female paratype A–C habitus in dorsal, ventral, and lateral views D–F, H prosoma in dorsal, lateral, ventral, and anterior views G abdomen in ventral view. Abbreviations: boc = booklung covers; cmp = clypeus median projection; esb = elevated seta base; ldi = labium deep incision; tp = triangular plate. Scale bars: 0.4 mm.

The specific name is derived from Chinese pinyin, “changzi”, which means “long moustache”, referring to the long, curved spines on the male’s endites; noun in apposition.

Known only from the type locality.

Holotype ♂: Myanmar, Kachin State, Putao, Hponkanrazi Wildlife Sanctuary, around Ziradum; 27°34.499'N, 97°03.546'E; elevation ca 1100 m; 19.XII.2016; Wu J. leg. (IZCAS AR-25141). Paratypes 1♀: Myanmar, same data as for holotype (IZCAS AR-25142); 2♂1♀: roadside between Wasadum and Ziradum; 27°32.305'N, 97°07.537'E; elevation ca 980 m; 12.XII.2016; Wu J. leg. (IZCAS AR-25143-25144-25145); 1♂: same data as preceding; 27°32.767'N, 97°07.283'E; elevation ca 970 m; 12.XII.2016; Wu J. leg. (IZCAS AR-25146); 3♀: around Ziradum Village; 27°33.465'N, 97°06.580'E; 1051 m; 8.V.2017; Wu J. leg. (IZCAS AR-25147-25148-25149); 1♀: same data as preceding; 27°35.305'N, 97°04.893'E; elevation ca 1140 m; 13.V.2017; Wu J. leg. (IZCAS AR-25150).

The new species is similar to T. gongshan Tong, Zhang & Li, 2019 but can be distinguished by the forked dorsal branch of the embolus system (Fig. 8E), the curved, strongly sclerotized posterior ridge (spr) of the female’s epigastric area (Fig. 9G), and the reticulate carapace (Figs 7D, F, 9D, F) of both sexes. Trilacuna gongshan has three long, tooth-like lobes in the embolus system, without a curved, strongly sclerotized posterior ridge in the female’s epigastric area, and with a granulate carapace in both sexes (Tong et al. 2019: figs 10–12, 24G, H).

Figure 7. 

Trilacuna hponkanrazi sp. nov., male holotype A–C habitus in dorsal, ventral, and lateral views D–F, H prosoma in dorsal, ventral, lateral, and anterior views G abdomen in ventral view (arrow shows the patches). Abbreviations: boc = booklung covers; ldi = labium deep incision. Scale bars: 0.4 mm.

Male. Body: yellow, chelicerae and sternum lighter; habitus as in Figure 7A–C; body length 1.49. Carapace: 0.74 long, 0.60 wide; sides finely reticulate; lateral margin rebordered (Fig. 7C). Eyes: ALE largest; PLE and PME nearly equal in size; ALE–PLE separated by less than ALE radius; PME touching each other; posterior eye row recurved as viewed from above, procurved as viewed from front (Fig. 7D, H). Clypeus: height about 1.25 times of ALE diameter. Mouthparts (Figs 7E, H, 16C, D). Sternum (Fig. 7E). Abdomen: 0.63 long, 0.48 wide; booklung covers ovoid, surface smooth (Fig. 7C); dorsal scutum not fused with epigastric scutum; apodemes absent; posterior spiracles not connected by groove; epigastric region with patches between the posterior spiracles (Fig. 7G). Palp (Figs 8, 14G–I): orange; 0.52 long (0.15, 0.09, 0.13, 0.15); femur greatly swollen (width/length = 0.74) (Fig. 8A, B); bulb oval, stout, tapering apically; embolus system (Fig. 8E, F, H) with a forked dorsal branch (db) and a small ventral lobe (svl) in prolateral view, with a small median branch (mb) and a lateral branch (lb) in retrolateral view.

Figure 8. 

Trilacuna hponkanrazi sp. nov., male holotype, left palp, SEM A, B, G prolateral, retrolateral and dorsal views C, D palpal bulb in prolateral and retrolateral views E, F, H distal part of palpal bulb in prolateral, retrolateral, and dorsal views. Abbreviations: db = dorsal branch; ds = dorsal setae; lb= lateral branch; smb= small median branch; svl = small ventral lobe; vs = ventral setae.

Female. Same as male except as noted. Habitus: as in Figure 9A–C. Body: length 1.43. Carapace: 0.70 long, 0.57 wide. Abdomen: 0.76 long, 0.45 wide. Epigastric area (Figs 9G, 15E): with a curved, strongly sclerotized posterior ridge (spr). Endogyne (Fig. 15F): with narrow, transverse sclerite (tsc), an anterior stick-shaped sclerite (as), and a posterior small globular structure (glo); transverse bars (tba) with two lateral apodemes (ap).

Figure 9. 

Trilacuna hponkanrazi sp. nov., female (IZCAS AR-25147) A–C habitus in dorsal, ventral, and lateral views D–F, H prosoma in dorsal, ventral, lateral, and anterior views G abdomen in ventral view. Abbreviation: ldi = labium deep incision; spr = sclerotized posterior ridge. Scale bars: 0.4 mm.

The specific name is a noun in apposition taken from the type locality.

Known only from the type locality.

1♀, Myanmar, Kachin State, Putao, roadside between Wasadum and Ziradum; 27°32.305'N, 97°07.537'E; elevation ca 980 m; 12.XII.2016; Wu J. leg. (IZCAS AR-25156).

Females of this species can be distinguished from other congeners by the semicircular plate of the epigastric area and the worm-shaped globular structure of the endogyne (Fig. 15G, H).

See Grismado et al. 2014.

India (Assam); Myanmar.

The specimens from Myanmar have a reticulate carapace and a nearly straight posterior eye row in dorsal view (Fig. 10D). By contrast, the specimens from India have a granulate carapace, and the posterior eye row is slightly recurved in dorsal view (Grismado et al. 2014: figs 35H, I).

Figure 10. 

Trilacuna loebli, female (IZCAS AR-25156) A–C habitus in dorsal, ventral, and lateral views D–F, H prosoma in dorsal, ventral, lateral, and anterior views G abdomen in ventral view. Abbreviations: boc = booklung covers; cmp = clypeus median projection; esb = elevated seta base; ldi = labium deep incision; sep = semicircular plate. Scale bars: 0.4 mm.

Holotype ♂: Myanmar, Kachin State, Putao, Hponkanrazi Wildlife Sanctuary; 27°32.032'N, 97°00.036'E; elevation ca 2010 m; 15.V.2017; Wu J. and Chen Z. leg. (IZCAS AR-25155).

The new species is similar to T. bilingua Eichenberger, 2011 but can be distinguished by the three black, thick setae on the endites of the male (Figs 11G, 16G, 16H) and the slender anterior branch (ab) of the embolus system (Fig. 12E, 12F, 12H). Trilacuna bilingua lacks black, thick setae on the endites, and the embolus system has two very short lobes basally (Eichenberger et al. 2011: fig. 5–6).

Figure 11. 

Trilacuna triseta sp. nov., male holotype A–C habitus in dorsal, lateral, and ventral views D–F, H, I prosoma in dorsal, lateral, ventral, posterior, and anterior views G labium and endites in ventral view (arrow shows the three black, strong setae). Abbreviations: boc = booklung covers; cmp = clypeus median projection; esb = elevated seta base; ldi = labium deep incision. Scale bars: 0.4 mm (A–F, H, I); 0.2 mm (G).

Male. Body: reddish brown, chelicerae and sternum lighter, legs yellow; habitus as in Figure 11A–C; body length 1.97. Carapace: 0.95 long, 0.74 wide; sides smooth; lateral margin rebordered (Fig. 11B); posterior surface with several large setal bases (Fig. 11H). Eyes: ALE largest; PLE and PME nearly equal in size; ALE–PLE separated by less than ALE radius; PME touching each other; posterior eye row recurved as viewed from above, procurved as viewed from front (Fig. 11D, I). Clypeus: height about 0.85 times of ALE diameter, with a triangular, pointed, median projection (cmp). Mouthparts (Figs 11F, I, 16G, H): endites with three thick, black setae. Sternum (Fig. 11F). Abdomen: 1.05 long, 0.80 wide; booklung covers ovoid, surface smooth (Fig. 11B); dorsal scutum not fused to epigastric scutum; apodemes present; posterior spiracles connected by groove (Fig. 11C). Palp (Figs 12, 14J–L): orange; 0.72 long (0.17, 0.11, 0.11, 0.33); femur elongated (width/length = 0.53) (Fig. 12A, B); bulb oval, tapering apically; embolus system (Fig. 12E, 12F, 12H) with an anterior branch (ab), a dorsal branch (db), a ventral branch (vb), and a median lobe (ml) in prolateral view.

Figure 12. 

Trilacuna triseta sp. nov., male holotype, left palp, SEM A, B, G prolateral, retrolateral, and dorsal views C, D palpal bulb in prolateral and retrolateral views E, F, H distal part of palpal bulb in prolateral, retrolateral, and dorsal views. Abbreviations: ab = anterior branch; db = dorsal branch; emb = embolus; ml = median lobe; vb = ventral branch.

Female. Unknown.

The species epithet is a noun in apposition composed of the Latin words tri (three) and seta and refers to the three black, thick setae on the male’s endites.

Known only from the type locality.

There are two species reported from a single female specimen in this study, and one described from a single male: T. loebli Grismado & Piacentini, 2014, T. zhigangi Tong & Li, sp. nov., and T. triseta Tong & Li, sp. nov., respectively. The following characters indicate that neither of the two females are conspecific with T. triseta Tong & Li, sp. nov. T. loebli is dark brown (Fig. 10A) with a reticulated carapace (Fig. 10D), and T. zhigangi has small eyes (Fig. 13A) and lacks the triangular, pointed, median projection of the clypeus (Fig. 13H). The male, T. triseta Tong & Li, sp. nov. has a reddish-brown body, a smooth carapace, normal-sized eyes, and a triangular, pointed, median projection (Fig. 11A, D, I).

Holotype ♀: Myanmar, Kachin State, Putao, Hponkanrazi Wildlife Sanctuary; 27°31.592'N, 96°58.266'E; elevation ca 2470 m; 15.V.2017; Wu J. and Chen Z. leg. (IZCAS AR-25157).

The new species is similar to T. bangla Grismado & Ramírez, 2014 but can be distinguished by the short, lateral apodemes (they do not reach the groove connecting the posterior spiracles) and the stick-shaped anterior sclerite of the endogyne (Fig. 15J). Trilacuna bangla has very long lateral apodemes (they distinctly extend beyond the groove connecting the posterior spiracles), and the anterior sclerite has long arms (Grismado et al. 2014: fig. 48A).

Female. Body: yellow, chelicerae and sternum lighter, legs yellow; habitus as in Figure 13A–C; body length 2.02. Carapace: 0.86 long, 0.71 wide; sides reticulate; lateral margin rebordered (Fig. 13F). Eyes: ALE largest; PLE and PME nearly equal in size; ALE–PLE separated by less than ALE radius; PME touching each other; posterior eye row recurved as viewed from above, procurved as viewed from front (Fig. 13D, H). Clypeus: height about 1.2 times of ALE diameter. Mouthparts (Figs 13E, H). Sternum (Fig. 13E). Abdomen: 1.20 long, 0.87 wide; booklung covers ovoid, surface smooth; postgastric scutum short, covering about 2/3 abdomen length. Epigastric area (Figs 13G, 15I): surface without external features. Endogyne (Fig. 15J): with narrow, transverse sclerite (tsc), an anterior stick-shaped sclerite (as), and a posterior small globular structure (glo); transverse bars (tba) with two lateral apodemes (ap).

Figure 13. 

Trilacuna zhigangi sp. nov., female holotype A–C habitus in dorsal, ventral, and lateral views D–F, H prosoma in dorsal, ventral, lateral, and anterior views G abdomen in ventral view. Abbreviation: esb = elevated seta base; ldi = labium deep incision. Scale bars: 0.4 mm.

Male. Unknown.

The species is named after Mr Zhigang Chen, one of the collectors of the holotype.

Known only from the type locality.

Figure 14. 

Trilacuna spp., left male palp A–C T. besucheti D–F T. changzi sp. nov. G–I T. hponkanrazi sp. nov. J–L T. triseta sp. nov. A, D, G, J prolateral views B, E, H, K dorsal views C, F, I, L retrolateral views. Scales: 0.2 mm.

Figure 15. 

Trilacuna spp., female copulatory organ A, B T. besucheti C, D T. changzi sp. nov. E, F T. hponkanrazi sp. nov. G, H T. loebli I, J T. zhigangi sp. nov. A, C, E, G, I ventral view B, D, F, H, J dorsal view. Abbreviations: ap = apodeme; as = anterior sclerite; db = darkened band; glo = globular structure; psp = posterior spiracle; sep = semicircular plate; tba = transverse bars; tp = triangular plate; tsc = transverse sclerite. Scales: 0.2 mm.

Figure 16. 

Trilacuna spp., male labium and endites, ventral view A, B T. changzi sp. nov., white arrow shows the long, strongly curved spines C, D T. hponkanrazi sp. nov. E, F T. besucheti G, H T. triseta sp. nov., black arrow shows the three black, strong setae. Abbreviations: bts = bent thick setae; cos = comb-like setae.