Trilacuna bilingua Eichenberger

Eichenberger, Beata & Kranz-Baltensperger, Yvonne, 2011, New Trilacuna species from Thailand, Malaysia and Sumatra (Araneae, Oonopidae), Zootaxa 2823, pp. 1-31 : 7-10

Trilacuna bilingua Eichenberger n. sp.

( Figs. 5–6 )

Type material: Holotype male (PBI_OON 00015933): West Malaysia: Pahang State: Cameron Highlands, Gunung Jasar , trail 11, 1550 m, tamisage, 24 March 1993, leg. I. Löbl & F. Calame, deposited in MHNG.

Etymology: The species epithet is a noun in apposition, composed of the Latin words bi (two) and lingua (tongue), and refers to the two tongue-like lobes baso-ventrally on the male palpal conductor.

Diagnosis: Trilacuna bilingua resembles T. merapi but can be easily distinguished by the two small conspicuous basal lobes (lo) ventrally on the palpal conductor (figs. 6. D–E) and by the lateral carapace margin with blunt denticles, and a second, strongly rebordered, undulated margin below (figs. 5. E–G).

Description: Description based on 1 male.

MALE (holotype): Body length 2.1 mm, proportion carapace length:abdominal length 1:1. Uniformly dark red-brown species (figs. 5. A–C).

Carapace ovoid, slightly elevated, surface smooth, with one tiny dorsal spike (sp), (fig. 5. C). Eyes posterior row recurved from above, straight from front (fig. 5. G). Sternum with radial furrows of large pits between coxae, medial surface coarsely reticulate (fig. 5. D), anterior margin with transverse groove; setae sparse, light, needlelike, evenly scattered. Mouthparts: Labium rectangular, not fused to sternum, anterior margin deeply incised (ldi), (figs. 5. H–I); endites slender, distally not branched, distal-outer part excavated (dex), (figs. 5. H–I).

Abdomen: Ovoid, dorsal scutum not fused to epigastric scutum, postepigastric scutum long, semicircular, with short, posteriorly directed lateral apodemes, posterior spiracles not connected by groove but connection indicated by dark belt.

Legs: Ventral apex of tibiae III and IV with some specialized hairs with fine, plumose, curved hair tip (see fig. 16. H), metatarsi III, IV and tarsus IV with harpoon-like hairs (see fig. 2. G). Femora without spines.

Male genitalia: Epigastric region with small dark dot (dd) posterior of sperm pore at level of posterior spiracles (fig. 6. A). Male palp (figs. 6. B–F): Embolus (em) light, long and straight, framed by some dorsal hairs (dh) (figs. 6. D–F); ventral conductor (vc) shorter than embolus, composed of a single branch enclosed by sparse, distally dense hairs (figs. 6. D–F). Bulb nearly as long as cymbium, stout, tapering apically (figs. 6. B–C). Femur elongated, slender (figs. 6. B–C).

FEMALE: unknown.

Remark: The patella of leg IV of the holotype carries a presumed parasite.

Distribution: Known only from the type locality in West-Malaysia, the Gunung Jasar in the Cameron Highlands.

Figures

FIGURE 5: Trilacuna bilingua n. sp. Male: A. habitus dorsal view; B. habitus ventral view; C. habitus lateral view; D. sternum ventral view; E. carapace dorsal view; F. carapace dorsal view, lateral margin; G. carapace anterior view; H – I. endites ventral view. Abbreviations: sp, spike; boc, booklung covers; ldi, labium deep incision; dex, distal excavation. Scale bars: A – C 1 mm; D – E, G 0.5 mm; F 100 Μm; H – I 200 Μm.

FIGURE 6: Trilacuna bilingua n. sp. Male: A. gonopore, ventral view; B – C. left palp, prolateral view; D – E. left embolus-conductor-complex, prolateral view; F. left embolus-conductor-complex, dorsal view. Abbreviations: dd, dark dot; emb, embolus; dh, dorsal hairs; vc, ventral conductor; lo, lobe. Scale bars: A – C 300 Μm; D, F 50 Μm; E 100 Μm.