Trilacuna merapi Kranz-Baltensperger & Eichenberger

Eichenberger, Beata & Kranz-Baltensperger, Yvonne, 2011, New Trilacuna species from Thailand, Malaysia and Sumatra (Araneae, Oonopidae), Zootaxa 2823, pp. 1-31 : 2-7

Trilacuna merapi Kranz-Baltensperger & Eichenberger n. sp.

( Figs. 1–4 )

Type material: Holotype male ( PBI_OON 00012408 ): Sumatra: West Sumatra Province : SE of Bukittinggi, Gunung Merapi , 0°23'28"S, 100°26'28"E, 2100–2200 m, evergreen hill forest, 4–5 June 2006, leg. P. Schwendinger, deposited in MHNG. 1 female paratype ( PBI_OON 00032081 ), collected with holotype, deposited in MHNG. 1 male paratype ( PBI_OON 00012080 ), collected with holotype, deposited in MHNG.

Etymology: The species epithet, a noun in apposition, refers to the type locality, Gunung Merapi .

Diagnosis: Trilacuna merapi can be recognized by the sternum which is coarsely reticulate in both sexes (figs. 1. F, I) in combination with the rather simple embolus-conductor-complex in the male (figs. 3. D–J).

Description: Description based on 16 males and 14 females (plus 4 males and 3 females for SEM).

MALE: Prosoma, abdominal scuta and mouthparts equally strongly and completely sclerotized (figs. 1. A–C). Body length 1.7 – 2.2 mm, proportion carapace length:abdominal length 1:1.1. Uniformly dark red-brown species (figs. 1. A–C).

Carapace broadly oval, slightly elevated, surface smooth, without spikes, lateral margin straight, not rebordered, with blunt denticles (figs. 1. E, G–H). Carapace setae distribution u-shaped. Clypeus sinuous in frontal view, anterior lateral eyes separated from edge of carapace by about their diameter, with needle-like setae, with a triangular, pointed, median projection (cmp) (figs. 2. A–B). Eyes six, well developed, arranged in a compact group, about subequal, roundish (fig. 2. A); posterior row recurved from above, straight from front (figs. 1. E; 2. A). Sternum (figs. 1. D, F, I) with smooth radial furrows between coxae, surface coarsely reticulate with a mix of small and large patches (sp and lp) (figs. 1. F, I), anterior margin with transverse groove; setae sparse, light, needle-like, evenly scattered. Mouthparts: Chelicerae straight, proximal region with one hair with elevated hair base (ehb) (figs. 2. A– B); promargin with row of flat, smooth hairs (fsh) in combination with feather-like hairs (flh) (fig. 2. E); labium rectangular, not fused to sternum, anterior margin deeply incised (ldi) (figs. 2. C–D); endites slender, distally only slightly branched (sdb) (fig. 2. D), distal inner margin with patch of fork-like serrated setae (fig. 2. F).

Abdomen: Ovoid, no soft tissue visible in dorsal and ventral view (figs. 1. A–C), dorsal scutum not fused to epigastric scutum, postepigastric and epigastric scutum fused, postepigastric scutum long, semicircular, apodemes absent, posterior spiracles not connected by groove but connection indicated by a dark belt (figs. 3. A–B), booklung covers (boc) large, ovoid, surface smooth (fig. 1. C).

Legs: Legs long, slender, without scopula, dorsal apex of metatarsi I–IV with small cuticular extension (fig. 2. I), tibiae I–IV with three, metatarsi I–IV with one trichobothrium each, trichobothrium base longitudinally narrowed, hood covered by closely spaced ridges ( Fig. 2 . H). Leg spination: tibiae I, II with 4 prolateral and 3 ventral spines; metatarsi I, II with 2 prolateral and 2 ventral spines each; legs III and IV without spines. Ventral apex of tibiae III and IV with one or few specialized hairs (sh) with fine, plumose, curved hair tip (see fig. 16. H of T. kropfi ); metatarsi III, IV and tarsus IV with harpoon-like hairs (fig. 2. G). Femur I with one enlarged hair.

Male genitalia: Epigastric region (figs. 3. A–B) with sperm pore small, oval, rebordered, situated between anterior and posterior spiracles, with scattered, plumose setae around sperm pore. Male palp (figs. 3. C–J): Palp slightly sclerotized, pale-orange. Femur elongated, slender (fig. 3. C–D), attached to patella basally. Tibia with three trichobothria. Cymbium not fused with bulb, with scattered setae (fig. 3. E). Bulb nearly as long as cymbium, stout, tapering apically (figs. 3. C–D). Embolus (emb) light, long and straight, framed by some dorsal hairs (dh); ventral conductor (vc) shorter than embolus, composed of a single branch, enclosed by sparse, distally dense hairs (figs. 3. F–J).

FEMALE: As in male except as noted. Slightly larger than male. Body length 2.1 – 2.6 mm, proportion carapace length:abdominal length 1:1.13. Tibia of female palp with three trichobothria. Postepigastric scutum long, semicircular, not fused to epigastric scutum. Posterior spiracles (psp) connected by groove (fig. 4. B); with two strongly sclerotized, recurved arches (sar) anterior to the posterior spiracles (fig. 4. A).

Female genitalia: Ventral view (figs. 4. A–B): Epigastric region with a procurved, dark brown lamella (la) and a procurved fold of uterus externus (fo) ending in two dark brown knobs (dkn); surface without external features except for a rugose surface around the epigastric furrow; with recurved, strongly sclerotized arches (sar) anterior to the posterior spiracles. Dorsal view (figs. 4 C–D): with narrow, transversally elongated, procurved fold of uterus externus (fo); with transversally elongated, procurved lamella (la); framed by an anterior paddle-like sclerite (psc) and lateral sclerites functioning as muscle attachments (A1).

Intraspecific variation: Ventral conductor of male palp with distal hairs more or less dense; variation in the amount of small and large patches on sternum (sp and lp) (fig. 1. I). Female postepigastric scutum semicircular, elongated or slightly shortened. Specimens from West Sumatra Province have roundish booklung covers with smooth surface (fig. 2. K). Specimens from Jambi Province have similar male palps as the holotype but ovoid booklung covers with striated surface (fig. 2. L).

Additional material examined: 3 males, 2 females (PBI_OON 00012798), Sumatra : Jambi Province : Gunung Tujuh, footpath to Lake Gunung Tujuh, 1500–2000 m, evergreen hill forest, 20 February 2000, leg. P. Schwendinger ; 2 females (PBI_OON 00012408), Sumatra : West Sumatra Province : SE of Bukittinggi, Gunung Merapi , 0°23'28"S, 100°26'28"E, 2100–2200 m, hill forest, 4–5 June 2006, leg. P. Schwendinger ; 2 males (PBI_OON 00012839), Sumatra : West Sumatra Province : Lake Maninjau, waterfall above Gasang, 740 m, evergreen rain forest, sifting, 10 February 2000, leg. P. Schwendinger ; 2 males (PBI_OON 00012075), Sumatra : Jambi Province: Gunung Kerinci, 3300 m, 12 November 1989, leg. D. Agosti, I. Löbl, & D. Burckhardt ; 1 female (PBI_OON 00012073), Sumatra : Jambi Province: W Gunung Tujuh Lake, 1400 m, 14 November 1989, leg. D. Agosti, I. Löbl & D. Burckhardt ; 1 male (PBI_OON 00012074), Sumatra : Jambi Province : km 8 Sungaipenuh to Tapan, 1200 m, 9 November 1989, leg. D. Agosti, I. Löbl & D. Burckhardt ; 1 female (PBI_OON 00012072), Sumatra : Aceh Province: Gunung Leuser N.P., Ketambe, 1000 m, 28–29 November 1989, leg. I. Löbl, D. Agosti & D. Burckhardt ; 1 male (PBI_OON 00012435), Sumatra : North Sumatra Province: 4 km N of Brastagi, Gunung Sibayak, 3°13'16"N, 98°29'50"E, 1600–1650 m, primary forest, 6–7 July 2006, leg. P. Schwendinger ; 1 male (PBI_OON 00012856), Sumatra : West Sumatra Province : Lake Maninjau, waterfall above Gasang, 720 m, evergreen rain forest, sifting, 9 February 2000, leg. P. Schwendinger ; 6 females (PBI_OON 00012756), Sumatra : Jambi Province : W of Kersik Tua, Gunung Kerinci, footpath to summit, 1800–1900 m, evergreen hill forest, sifting, 16 February 2000, leg. P. Schwendinger ; 2 males, 1 female (PBI_OON 00012755), Sumatra : Jambi Province : W of Kersik Tua, Gunung Kerinci, footpath to summit, 2160 m, evergreen hill forest, sifting, 17–18 February 2000, leg. P. Schwendinger ; 2 males (PBI_OON 00012071), Sumatra : Jambi Province: Gunung Kerinci, 1900 m, 13 November 1989, leg. D. Agosti, I. Löbl & D. Burckhardt.

Distribution: Sumatra, West Sumatra Province and Jambi Province.

Figures

FIGURE 1: Trilacuna merapi n. sp. Male: A. habitus dorsal view; B. habitus ventral view; C. habitus lateral view; D. sternum ventral view; E. carapace dorsal view; F. sternum ventral view, SEM; G. carapace dorsal view, SEM; H. carapace lateral margin, dorsal view. Female: I. sternum ventral view. Abbreviations: boc, booklung covers; sp, small patch; lp, large patch. Scale bars: A – C 1 mm; D – H 0.5 mm, I 0.2 mm.

FIGURE 2: Trilacuna merapi n. sp. Male: C. labium ventral view; D. endites ventral view, SEM; F. endites, distal fork-like setae, SEM; G. metatarsus IV, ventral view, harpoon-like setae; H. trichobothrium hood, metatarsus I, dorsal view; I. metatarsus I, distal tip, prolateral view; J. abdomen anterior view. Female: A. carapace anterior view; B. carapace anterior view, SEM; E. chelicerae right, inner margin, anterior view; K. booklung covers anterior view; L. booklung covers lateral view. Abbreviations: cmp, clypeus median projection; ehb, elevated hair base; ldi, labium deep incision; sdb, slight distal branch; fsh, flat smooth hairs; flh, feather-like hairs; boc, booklung covers. Scale bars: A – B, J 0.5 mm; C – D 200 Μm; E 100 Μm; F – G 20 Μm; H, K – L 10 Μm; I 50 Μm.

FIGURE 3: Trilacuna merapi n. sp. Male: A. gonopore ventral view; B. gonopore ventral view, SEM; C – D. left palp, prolateral view; E. left palp, prolateral view, SEM; F. left embolus, prolateral view; G – H. left embolus, prolateral view, SEM; I – J right embolus, retrolateral view, SEM. Abbreviations: psp, posterior spiracles; emb, embolus; dh, dorsal hairs; vc, ventral conductor. Scale bars: A – D 300 Μm; E 100 Μm; F 50 Μm; G – H 20 Μm; I – J 10 Μm.

FIGURE 4: Trilacuna merapi n. sp. Female: A. epigastric region, ventral view; B. epigastric region ventral view, SEM; C – D. epigastric region, dorsal view. Abbreviations: psp, posterior spiracles; la, lamella; fo, fold of uterus externus; dkn, dark knob; psc, paddle-like sclerite; A 1, sclerites functioning as muscle attachments. Scale bars: A – D 300 Μm.