Pholcus bukittimah Huber

Bernard A. Huber, Joseph K. H. Koh, Amir-Ridhwan M. Ghazali, Kamil A. Braima, Olga M. Nuñeza, Charles Leh Moi Ung & Booppa Petcharad, 2016, New leaf- and litter-dwelling species of the genus Pholcus from Southeast Asia (Araneae, Pholcidae), European Journal of Taxonomy 200, pp. 1-45 : 18-21

Pholcus bukittimah Huber sp. nov.

urn:lsid:zoobank.org:act:93CDF3AF-2A6D-4AFE-926B-3FE43BBD495E

Figs 59–62 , 67–71 , 79 , 87–89

Diagnosis

Easily distinguished from most similar known relatives (other species of the P. ethagala group on the Malay Peninsula) by morphology of male palps ( Figs 67–68 ; extremely long curved male palpal trochanter apophysis; procursus with slender dorsal process and long whitish retrolateral area), and by details of female internal genitalia ( Figs 70–71 ; anterior triangular sclerite; semicircular pore plates; posterior rectangular structure).

Etymology

The species is derived from the type locality; noun in apposition.

Material examined

Holotype

SINGAPORE: ♂, ZFMK ( Ar 15706 ), Bukit Timah, Dairy Farm Nature Park (1.360°N, 103.778°E), 50 m a.s.l., leaf litter near Wallace Trail, 15 Feb. 2015 (B.A. Huber, J.K.H. Koh) .

Other material

SINGAPORE: 1 ♂, 1 ♀, ZFMK ( Ar 15707 ), same data as holotype ; 2 ♀♀, in absolute ethanol, ZFMK ( Mal 212, Mal 256 ), same data .

Description

Male (holotype)

MEASUREMENTS. Total body length 3.5, carapace width 0.95. Leg 1: 29.5 (6.9 + 0.4 + 7.0 + 13.4 + 1.8), tibia 2: 4.0, tibia 3: 2.5, tibia 4: 3.9; tibia 1 L/d: 84. Distance PME-PME 440 µm, diameter PME 115 µm, distance PME-ALE ~35 µm; AME absent.

COLOR. Carapace pale ochre-yellow with light brown median V-mark posteriorly, clypeus light brown, ocular area not darkened; sternum whitish; legs ochre-yellow with darker brown patellae and tibiametatarsus joints; abdomen gray with some black marks dorsally and laterally.

BODY. Habitus as in Figs 59–60 ; ocular area raised and each triad on long stalk ( Fig. 79 ); carapace without median furrow; clypeus unmodified; sternum wider than long (0.62/0.48), unmodified.

CHELICERAE. As in Fig. 69 , with single pair of frontal proximal apophyses; without distal modification; without stridulatory ridges.

PALPS. As in Figs 67–68 ; coxa unmodified; trochanter with very long curved retrolatero-ventral apophysis and small weakly sclerotized retrolateral process; femur with indistinct ventral humps proximally and distally; tarsus with large rounded elongation; procursus complex, proximal part with distinctive dorsal process; hinged distal part with large whitish area retrolaterally and transparent fringed processes prolaterally; bulb with very large appendix, long slender embolus, and small uncus-like process partly sclerotized as continuation of proximal bulbal sclerite.

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium on tibia 1 at 2%; prolateral trichobothrium absent on tibia 1, present on other tibiae; tarsus 1 pseudosegments very indistinct, apparently irregular.

Male (variation)

Tibia 1 in other male: 7.7.

Female

In general similar to male ( Fig. 62 ) but eye triads not on stalks and much closer together than in male (PME-PME distance: 200 µm); clypeus and ocular area frontally dark brown, with pair of small black marks in area of AME (but without lenses). Tibia 1 in 1 female: 5.8. Epigynum weakly sclerotized (Fig. 87), only posterior rim slightly more sclerotized, with small dark ‘knob’ ( Fig. 70 ); large anterior triangular internal sclerite visible through cuticle; internal genitalia as in Figs 71 , 88–89.

Natural history

All specimens were found in an area of the forest where large dead leaves on the ground were abundant. They built their domed webs closely attached to the undersides of the leaves. A few eggs in an egg-sac of one female were parasitized by Idris wasps ( Fig. 62 ).

Distribution

Known from type locality in Singapore only ( Fig. 1 ).

Figures

Fig. 1. Known distributions of the Pholcus ethagala group (Malay Peninsula and Sumatra; Sri Lankan species not shown), of the P. tambunan group (Borneo) and of the P. domingo group (Philippines).

Figs 59 – 66. Live specimens. 59 – 62. Pholcus bukittimah Huber sp. nov., Dairy Farm, ♂, penultimate ♂, and ♀ with partly parasitized egg-sac. 63 – 66. P. barisan Huber sp. nov., Bukit Barisan, ♂ and ♀♀ with variably expanded abdomens.

Figs 67 – 71. Pholcus bukittimah Huber sp. nov. (ZFMK, Ar 15706 – 07). 67 – 68. Left male palp, prolateral and retrolateral views; arrow points at uncus-like process of proximal bulbal sclerite. 69. Male chelicerae, frontal view. 70 – 71. Cleared female genitalia, ventral and dorsal views. Scale bars: 67 – 68, 70 – 71 = 0.5 mm; 69 = 0.3 mm.

Figs 77 – 80. Male prosomata, frontal views. 77. Pholcus tanahrata Huber sp. nov. 78. P. uludong Huber sp. nov. 79. P. bukittimah Huber sp. nov. 80. P. barisan Huber sp. nov.