Pholcus bario 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 (200), pp. 1-45 : 31-33

Pholcus bario Huber sp. nov.

urn:lsid:zoobank.org:act:D680CB67-1525-4263-B8D4-8E44E587C51E

Figs 97–100 , 121–124 , 128–130

Diagnosis

Easily distinguished from most similar known relative ( P. tambunan Huber sp. nov.) by morphology of male palps ( Figs 121–122 ; longer trochanter apophysis; more slender femur; distinctive structures on tip of procursus), by different shapes of frontal cheliceral apophyses ( Fig. 120 ), and by longer epigynal scape ( Fig. 123 ).

Etymology

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

Material examined

Holotype

MALAYSIA-BORNEO: ♂, ZFMK ( Ar 15716 ), Sarawak, Bario , forest along river W of town (3.736°N, 115.437– 115.443°E), 1150–1250 m a.s.l., on underside of leaf, 30 Jul. 2014 (B.A. Huber, S.B. Huber) .

Other material

MALAYSIA-BORNEO: 2 ♂♂, 2 ♀♀, ZFMK ( Ar 15717–18 ), same data as holotype ; 2 ♀♀, in absolute ethanol, ZFMK ( Bor 232 ), same data .

Description

Male (holotype)

MEASUREMENTS. Total body length 3.9, carapace width 0.9. Leg 1: 34.5 (8.1 + 0.4 + 8.2 + 15.5 + 2.3), tibia 2: 5.3, tibia 3: 3.2, tibia 4: 4.7; tibia 1 L/d: 104. Distance PME-PME 370 µm, diameter PME 95 µm, distance PME-ALE ~35 µm; no trace of AME.

COLOR. Carapace whitish with dark median mark widening anteriorly and including ocular area and clypeus in upper part and laterally; sternum whitish; legs pale ochre-yellow with dark brown patellae and tibia-metatarsus joints; abdomen pale ochre-gray with black marks dorsally and laterally, monochromous ventrally.

BODY. Habitus as in Figs 97–99 ; ocular area slightly raised, each triad on additional short stalk directed towards lateral ( Fig. 120 ); carapace without median furrow; clypeus unmodified; sternum wider than long (0.64/0.52), unmodified.

CHELICERAE. As in Fig. 120 , with distinctive pair of frontal apophyses (large flat curved plates) and small rounded lateral humps; without modified hairs; without stridulatory ridges.

PALPS. As in Figs 121–122 ; coxa unmodified; trochanter with strong ventral apophysis; femur cylindrical, with two small retrolateral humps proximally and small ventral hump at half length; procursus with strong ventral ‘knee’, with distinctive small prolateral sclerotized process at 1/3 length (arrow in Fig. 121 ), distal half with large whitish area retrolaterally, tip complex with distinctive sclerites; bulb elongated, long appendix with distinctive prolateral process provided with small teeth, further teeth along ventral rim, proximal processes of appendix ‘guiding’ embolus between them; embolus long and weakly sclerotized.

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 not seen in dissecting microscope.

Male (variation)

Tibia 1 in 2 other males: 7.8, 8.0.

Female

In general similar to male ( Fig. 100 ) but carapace mark only in posterior half; ocular area dark as in male but clypeus light. Eye triads closer together than in male (PME-PME distance: 230 µm). Dark marks on abdomen less distinct. Tibia 1 in 2 females: 6.6 (both). Epigynum weakly sclerotized ( Fig. 128 ), wide transversal plate with long scape directed towards anterior ( Fig. 123 ); dark internal arch and lateral posterior structures visible through cuticle; internal genitalia as in Figs 124 , 129, 130 , with pair of highly distinctive three-layered telescopic tubes.

Natural history

All specimens were found in one small section of forest along a small river. No further specimens were found in two days of intensive search. They built barely visible webs on the undersides of live leaves, and often shared webs with large numbers of Diptera ( Cecidomyiidae , in ZFMK).

Distribution

Known from type locality in northern Borneo (Sarawak) 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 93 – 100. Live specimens. 93 – 96. Pholcus tambunan Huber sp. nov., Crocker Range, ♂, penultimate ♂, and ♀ with egg-sac. 97 – 100. P. bario Huber sp. nov., Bario, ♂ and ♀ with egg-sac.

Figs 120 – 124. Pholcus bario Huber sp. nov. (ZFMK, Ar 15717 – 18). 120. Male prosoma, frontal view. 121 – 122. Left male palp, prolateral and retrolateral views; arrow points at prolateral finger-shaped process of procursus. 123 – 124. Cleared female genitalia, ventral and dorsal views. Scale bars: 120, 123 – 124 = 0.3 mm; 121 – 122 = 0.5 mm.

Figs 125 – 130. Epigyna, ventral views, and cleared female genitalia, ventral and dorsal views. 125 – 127. Pholcus tambunan Huber sp. nov. (ZFMK, Ar 15712). 128 – 130. P. bario Huber sp. nov. (ZFMK, Ar 15718).