Pholcus halabala Huber, 2011

Berhard A. Huber, Booppa Petchard, Charles Leh Moi Ung, Joseph K. H. Koh & Amir R. M. Ghazali, 2016, The Southeast Asian Pholcus halabala species group (Araneae, Pholcidae): new data from field observations and ultrastructure, European Journal of Taxonomy 190, pp. 1-55 : 7-10

Pholcus halabala Huber, 2011

Figs 1–6 , 18–28

Pholcus halabala Huber, 2011: 128 –131, figs 495–496, 517–518, 530–535 (♂♀).

Diagnosis

Easily distinguished from most other species in halabala core group by simple triangular uncus and short curved appendix with simple rounded tip (fig. 530 in Huber 2011; Fig. 24 ), and by distinctive sclerite anteriorly in internal female genitalia (fig. 533 in Huber 2011; similar in Ph. lintang sp. nov, cf. Fig. 37 ); from very similar Ph. sepaku only by shape of procursus (distinctive distal elements; compare figs 535 and 536 in Huber 2011).

New material examined

THAILAND: 1 ♀, 2 juvs, in absolute ethanol, ZFMK ( Mal 302, 315 ), Narathiwat , Hala Bala Wildlife Sanctuary, ‘site 1’, forest at river near headquarters (5°47.8' N, 101°49.9' E), 90 m a.s.l., on leaves, 1–2 Mar. 2015 (B.A. Huber, B. Petcharad) .

MALAYSIA: 1 ♂ in ZFMK ( Ar 15000 ), Kedah, Gunung Jerai, forest near Sri Perigi Waterfall (5°48.3' N, 100°24.6' E), 100–200 m a.s.l., on leaf, 27 Feb. 2015 (B.A. Huber) ; 1 juv., in absolute ethanol, ZFMK ( Mal 292 ), same data ; 1 ♂, 1 ♀, ZFMK ( Ar 15001 ), Pulau Pinang, Penang National Park near Teluk Bahang (5°27.7' N, 100°12.1' E), 10–50 m a.s.l., on leaves, 28 Feb. 2015 (B.A. Huber) ; 1 ♂, in absolute ethanol, ZFMK ( Mal 119 ), same data ; 1 ♀, ZFMK ( Ar 15002 ), Perak, Gunung Liang (3°47.7' N, 101°32.0' E), 250 m a.s.l., forest along river, on leaf, 22 Feb. 2015 (B.A. Huber, A.R.M. Ghazali, K.A. Braima) ; 2 ♀♀, 1 juv., in absolute ethanol, ZFMK ( Mal 268 ), same data ; 1 ♂, ZFMK ( Ar 15003 ), Pahang, Ulu Dong (3°56.2' N, 102°01.9' E), 190 m a.s.l., forest near river, on leaf, 21 Feb. 2015 (B.A. Huber, A.R.M. Ghazali, K.A. Braima) ; 1 ♀, in absolute ethanol, ZFMK ( Mal 253 ), same data ; 1 ♂, ZFMK ( Ar 15004 ), Selangor, Kemensah (3°13.31' N, 101°47.57' E), 230 m a.s.l., forest along stream, on leaf, 19 Feb. 2015 (B.A. Huber, A.R.M. Ghazali, K.A. Braima, M. Muslimin) ; 2 ♂♂, 1 ♀, ZFMK ( Ar 15005 ), Johor, Gunung Ledang, forest near Puteri Falls (2°21.2'– 2°21.6' N, 102°37.8'– 102°38.1' E), 100–300 m a.s.l., on leaves, 17 Feb. 2015 (B.A. Huber) ; 1 ♀, 4 juvs, in absolute ethanol, ZFMK ( Mal 239 ), same data ; 2 ♀♀, ZFMK ( Ar 15006 ), Gunung Ledang, forest near Puteri Falls (2°21.3' N, 102°38.1' E), 110 m a.s.l., on leaves, 18 Feb. 2015 (B.A. Huber), night collecting ; 1 juv. in absolute ethanol, ZFMK ( Mal 244 ), same data .

SINGAPORE: 1 ♂, ZFMK ( Ar 15007 ), Upper Selatar Reservoir Park (1°24.0' N, 103°48.4' E), 20 m a.s.l., on leaf, 15 Feb. 2015 (B.A. Huber, D. Court) ; 3 juvs, in absolute ethanol, ZFMK ( Mal 224 ), same data ; 2 ♂♂, ZFMK ( Ar 15008 ), Dairy Farm Nature Park (1°21.6' N, 103°46.7' E), 50 m a.s.l., on leaves, 15 Feb. 2015 (B.A. Huber, J. Koh) ; 1 ♀, 2 juvs, in absolute ethanol, ZFMK ( Mal 214 ), same data ; 2 ♂♂, 1 ♀, ZFMK ( Ar 15009 ), MacRitchie Reservoir Park (1°21.3' N, 103°48.8' E), 50 m a.s.l., on leaves, 14 Feb. 2015 (B.A. Huber, J. Koh, D. Court) ; 1 ♀, 4 juvs, in absolute ethanol, ZFMK ( Mal 201 ), same data .

INDONESIA: 1 ♂, 1 ♀, 1 juv., RMNH, Sumatra, Gunung Leuser National Park at Bohorok [3.54°N, 98.12°E], 1000 m a.s.l., from leaves, 7–10 Aug. 1982, collector unknown .

Description – amendments

Male ocular area on each side with four strong spines ( Figs 18–20 ); apparently without gland openings ( Fig. 23 ); tarsus 4 comb-hairs of the simplified Pholcus - type (cf. Huber & Fleckenstein 2008), with three lateral tines ( Fig. 27 ); procursus with retrolateral distal pocket ( Figs 21–22 ); distal cheliceral apophyses with two cone-shaped teeth (modified hairs) each ( Fig. 28 ); gonopore with four epiandrous spigots ( Fig. 26 ); ALS with one widened, one pointed, and six smaller cylindrically shaped spigots of varying sizes ( Fig. 25 ).

Variation

Previously, this species was known only from southern Thailand (type locality) and Sumatra ( Huber 2011). Specimens from Sumatra were assigned tentatively because of minor differences in the procursus. The new specimens above support the idea that this is intraspecific variation rather than an indication of species limits. First, the ventral distal spine of the procursus varies continuously among localities, with specimens from Singapore having a short spine like specimens from Sumatra, and specimens from Malaysia being intermediate between those from Singapore and Thailand. Most deviating are specimens from Pulau Pinang, where the ventral distal process of the procursus carries three spines instead of only one. Second, the shape of the dorsal process of the procursus varies strongly with the angle at which it is viewed. If the procursus is viewed in slightly dorsal view, the process looks as in the original description ( Huber 2011, fig. 531); if the procursus is viewed in perfect retrolateral view, the process appears slightly wider.

The usual pattern on the carapace consists of two V-marks on the posterior half ( Figs 1, 6 ). In some specimens, these marks are fused into larger marks or even into a single large mark that covers the entire posterior half of the carapace ( Fig. 5 ). Tibia 1 in newly collected specimens: 12 males: 7.0–9.1 (mean 8.0); 6 females: 6.4–7.7 (mean 7.0).

Natural history

Even though this species is widespread, it seemed to be extremely rare at most localities. This explains the low specimen numbers even though it was searched for with considerable effort. At the type locality, three days of intensive search yielded only one female and two juveniles. The ATOL Expedition in 2003 (including several experienced arachnologists using a variety of collecting techniques) also found only one adult specimen. At some localities (Gunung Jerai; Penang), Ph. halabala was found together with Ph. erawan , but Ph. halabala seemed to prefer dicot leaves while Ph. erawan was mostly found on monocot leaves. Otherwise these two species are barely distinguishable in the field. Webs consisted mainly of round platforms attached to the undersides of leaves. Small silk tufts ( Fig. 4 ) were observed in some webs at most localities. Egg-sacs are carried under the prosoma ( Figs 3, 5–6 ).

Distribution

Widely distributed from southern Thailand to Singapore and Sumatra ( Fig. 17 ).

Figures

Fig. 17. Known distribution of the core group of the Pholcus halabala species group.

Figs 1 – 8. Live specimens, Pholcus halabala Huber, 2011 (1 – 6) and Ph. ubin Huber, sp. nov. (7 – 8). 1. ♂ from MacRitchie, Singapore. 2. ♂ from Gunung Jerai, Malaysia. 3. ♀ with egg-sac from Gunung Liang, Malaysia. 4. Juvenile in web with silk tufts, Upper Selatar, Singapore. 5. ♀ with egg-sac from Hala Bala, Thailand. 6. ♀ with egg-sac from Ulu Dong, Malaysia. 7 – 8. ♂ and ♀ from Pulau Ubin, Singapore.

Figs 18 – 28. Pholcus halabala Huber, 2011, ZFMK Ar 15008. 18. Male ocular area, frontal view. 19. Modified hairs on male ocular area, dorsal view. 20. Male prosoma, frontal view. 21 – 22. Right procursus (and trochanter apophysis), retrolateral and retrolatero-distal views (arrows point at distal pocket). 23. Modified hairs on male ocular area. 24. Left bulbal processes, prolateral (slightly ventral) view. 25. Male ALS. 26. Male gonopore. 27. Comb-hairs on male tarsus 4. 28. Male distal cheliceral apophysis. Abbreviations: a = appendix; AME = anterior median eyes; e = embolus; p = procursus; tr = trochanter; u = uncus. Scale lines: 10 µm (25, 27); 20 µm (28); 30 µm (23); 40 µm (26); 80 µm (24); 100 µm (19, 21 – 22); 200 µm (18); 300 µm (20).

Figs 34 – 38. Pholcus lintang Huber, sp. nov., ZFMK Ar 15015. 34 – 35. Left male palp, prolateral and retrolateral views. 36. Male chelicerae, frontal view. 37 – 38. Cleared female genitalia, ventral and dorsal views. Abbreviations: a = appendix; b = genital bulb; e = embolus; p = procursus; u = uncus. Scale lines: 0.3 mm (36 – 38); 0.5 mm (34 – 35).