Pholcus mulu Huber

Huber, Bernhard A., Nuñeza, Olga M. & Leh Moi Ung, Charles, 2016, The Philippine hair wax spiders and their relatives: revision of the Pholcus bicornutus species group (Araneae, Pholcidae), European Journal of Taxonomy 225, pp. 1-34 : 12-15

Pholcus mulu Huber , sp. nov.

urn:lsid:zoobank.org:act:36311195-45A6-4B19-BFD2-31C0687775FE

Figs 27–29 , 36–37 , 40–44

Diagnosis

Easily distinguished from most similar known relatives (species with horns between eye triads carrying brushes of unglued hairs and with simple, unhinged procursi: P. arayat , P. pagbilao , P. schawalleri , P. baguio sp. nov., P. kawit sp. nov.) by large round uncus with pointed process ( Fig. 40 ) and by large prolateral sclerite distally on procursus ( Fig. 40 ); from most species (except P. kawit sp. nov.) also by undivided median dark band ventrally on abdomen ( Fig. 37 ). From other species of the P. bicornutus group ( P. bicornutus and P. olangapo sp. nov.) by unhinged procursus, presence of appendix, large epigynal plate, and by absence of curved hairs on legs.

Etymology

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

Material examined

Holotype

MALAYSIA-BORNEO: ♁, Sarawak, Gunung Mulu National Park , forest near Deer Cave (4.027° N, 114.818° E), 60 m a.s.l., among rocks , 23 Jul. 2014 (B.A. Huber, S.B. Huber), ZFMK ( Ar 15500 ) .

Other material

MALAYSIA-BORNEO: 2 ♁♁, 10 ♀♀, ZFMK ( Ar 15501–02 ) and 1 ♂, 1 ♀, SMK, same data as holotype ; 1 ♁, 1 ♀, 1 juv., in absolute ethanol, same data, ZFMK ( Bor 238 ) ; 2 ♁♁, 4 ♀♀, 1 juv., Gunung Mulu National Park , forest near Lagang Cave (4.051° N, 114.822° E), 60 m a.s.l., domed webs among rocks , 24 Jul. 2014 (B.A. Huber, S.B. Huber), ZFMK ( Ar 15503 ) .

Description

Male (holotype)

MEASUREMENTS. Total body length 6.8, carapace width 1.7. Leg 1: 62.9 (14.4 + 0.8 + 15.1 + 28.5 + 4.1), tibia 2: 9.6, tibia 3: 6.0, tibia 4: 8.4; tibia 1 L/d: 94. Distance PME-PME 480 µm, diameter PME 180 µm, distance PME-ALE ~40 µm; distance AME-AME 50 µm, diameter AME 80 µm.

COLOR. Carapace pale ochre, with wide median brown mark including ocular area, without lateral marks ( Fig. 36 ); clypeus not darkened; sternum dark brown; legs in live specimens bluish, in alcohol ochre to light brown, tips of femora and tibiae whitish; abdomen pale gray, dorsally with dark cuticular marks that are fused above spinnerets, with indistinct internal darker marks visible through cuticle dorsally and laterally; ventrally with undivided wide brown band between gonopore and spinnerets.

BODY. Habitus as in Figs 36–37 ; ocular area raised, each eye triad on additional short hump directed towards lateral, with pair of processes between eye triads, each with distal brush of hairs; carapace without median furrow; clypeus unmodified; sternum wider than long (1.00/0.85), unmodified.

CHELICERAE. As in Fig. 42 , with small lateral and frontal apophyses proximally and dark distal apophyses near median line provided with two small modified (cone-shaped) hairs each; without stridulatory ridges.

PALPS. As in Figs 40–41 ; coxa unmodified; trochanter with retrolateral process and S-shaped ventral apophysis; femur with small dorsal hump proximally, finger-shaped retrolateral process proximally, and distinct ventral process; tibia large, with small but distinct ventral cavity (for proximal bulbal sclerite); procursus complex distally, with distinctive prolateral sclerite and membranous structures; bulb with large rounded uncus with pointed process, weakly sclerotized and distally widening embolus, appendix with small prolateral spine, distally curved towards retrolateral.

LEGS. Without spines or curved hairs; few vertical hairs; retrolateral trichobothrium on tibia 1 at 3.5%; prolateral trichobothrium absent on tibia 1, present on other tibiae; tarsus 1 with>30 pseudosegments, only distally about 20 fairly distinct.

Male (variation)

Internal dark abdominal marks more distinct in other males. Tibia 1 in 5 other males: 13.9–16.0 (mean 14.9).

Female

In general similar to male but ocular area less elevated, eye triads closer together (distance PME-PME 320 µm), without processes between eye triads. Tibia 1 in 13 females: 12.3–14.0 (mean 13.3). Epigynum large trapezoidal plate ( Figs 27 , 43 ) with anterior ‘knob’; internal genitalia as in Figs 29 and 44 , anterior sclerite medially distinctively curved backwards. ALS with one widened, one pointed, and five very small conical spigots (~1.5–3 µm wide and ~3–6 µm long).

Natural history

Specimens were found in large domed sheet webs (diameter up to ~ 50 cm) among rocks near the ground. When disturbed they moved very rapidly towards the periphery of the web.

Distribution

Known from type locality in Sarawak only ( Fig. 2 ).

Figures

Figs 24 – 35. Epigyna, ventral views, and cleared female genitalia, ventral and dorsal view. 24 – 26. Pholcus olangapo Huber, sp. nov., ZFMK Ar 15498. 27 – 29. Pholcus mulu Huber, sp. nov., ZFMK Ar 15502. 30 – 32. Pholcus kawit Huber, sp. nov., ZFMK Ar 15505. 33 – 35. Pholcus baguio Huber, sp. nov., ZFMK Ar 15508.

Figs 36 – 39. Live specimens. 36 – 37. Pholcus mulu Huber, sp. nov., ♁, Gunung Mulu. 38 – 39. Pholcus kawit Huber, sp. nov., ♁ and ♀, Mt. Matutum.

Figs 40 – 44. Pholcus mulu Huber, sp. nov., ZFMK Ar 15501 – 02. 40 – 41. Left male palp, prolateral and retrolateral views. 42. Male chelicerae, frontal view. 43 – 44. Cleared female genitalia, ventral and dorsal views. Scale lines: 40 – 41 = 1 mm; 42 – 44 = 0.5 mm.

Figs 1 – 2. Known distributions of the two subgroups of the Pholcus bicornutus species group.