Pholcus baguio 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 : 17-24

Pholcus baguio Huber , sp. nov.

urn:lsid:zoobank.org:act:753EAC47-AFE0-4704-A564-696C4DD0A14F

Figs 33–35 , 50–52 , 58–76

Diagnosis

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. kawit sp. nov., P. mulu sp. nov.) by distal modifications of procursus (dorsal pointed process; large prolateroventral process; Fig. 59 ), by relatively wide and short palpal femur ( Fig. 59 ), and by female genitalia (epigynum with pair of dark lateral areas; internal genitalia with large transversal sclerite; Figs 33–35 ); from P. pagbilao also by simpler appendix ( Figs 58 , 71–72 ); from P. arayat also by relatively wider abdomen ( Figs 50–52 ); from P. kawit sp. nov. and P. mulu sp. nov. also by divided median band ventrally on abdomen ( Fig. 51 ); from P. schawalleri also by much more slender uncus ( Fig. 58 ). From other species of the P. bicornutus group ( P. bicornutus ; 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

PHILIPPINES: ♁, Luzon , Benguet Prov., near Baguio , Mt. Kabuyao , N slope (16.374° N, 120.557° E), 1200–1400 m a.s.l., among rocks , 2 Mar. 2014 (B.A. Huber), ZFMK ( Ar 15506 ) .

Other material

PHILIPPINES: 17 ♁♁, 10 ♀♀, 1 juv., ZFMK ( Ar 15507–08 ) and 1 ♂, 1 ♀, MSU-IIT, same data as holotype, among rocks and vegetation ; 1 ♀, 3 juvs, in absolute ethanol, same data, ZFMK ( Phi 204 ) ; 7 ♁♁, 16 ♀♀, Benguet, “ Tuba , Asin road , 10 km S of Baguio ” [~ 16.37° N, 120.62° E], rock wall at waterfall , 12 Nov. 1979 (P. Lehtinen), ZMT .

Description

Male (holotype)

MEASUREMENTS. Total body length 7.7, carapace width 1.8. Leg 1: 51.2 (12.5 + 0.8 + 12.4 + 22.8 + 2.7), tibia 2: 8.3, tibia 3: 5.3, tibia 4: 7.5; tibia 1 L/d: 67. Distance PME-PME 380 µm, diameter PME 140×160 µm, distance PME-ALE ~40 µm, distance AME-AME 30 µm, diameter AME 100 µm.

COLOR. Carapace ochre to orange, with wide median brown mark including ocular area and clypeus (except rim), connecting posteriorly with lateral submarginal brown bands ( Fig. 50 ); sternum monochromous light brown to orange, labium darker; legs light brown, dark rings subdistally on femora and tibiae and in patella area, tips of femora and tibiae lighter; abdomen ochre-gray, dorsally with several pairs of dark cuticular marks that are fused above spinnerets, laterally with indistinct internal darker marks visible through cuticle; ventrally with wide brown band divided into anterior and posterior parts separated by light V-shaped space.

BODY. Habitus as in Fig. 50 ; ocular area raised, each eye triad on additional short hump directed towards lateral ( Fig. 63 ), with pair of long processes between eye triads directed towards posterior, each with distal brush of hairs curved upwards, hairs not ‘glued’ together ( Figs 64–67 ); carapace without median furrow ( Fig. 64 ); clypeus unmodified; sternum wider than long (1.10/0.85), unmodified. ALS with one widened, one pointed, and three very small conical spigots ( Fig. 74 ). Gonopore with four epiandrous spigots.

CHELICERAE. As in Fig. 60 , small lateral and frontal apophyses proximally and dark distal apophyses near median line provided with two small modified (cone-shaped) hairs each ( Fig. 73 ); without stridulatory ridges.

PALPS. As in Figs 58–59 ; coxa unmodified; trochanter with short conical retrolateral process and longer ventral apophysis with distinctive tip ( Fig. 69 ); femur with distinct retrolateral process proximally, small dorsal hump, and distinct darkened ventral apophysis; tibia with dark dorsal band, also ventrally darkened, with very small and indistinct ventral cavity; tarsal organ capsulate ( Fig. 68 ); procursus with distinctive pointed process dorsally and large process prolatero-ventrally ( Figs 69–70 ); bulb with large uncus ( Figs 58 , 71 ), weakly sclerotized wide embolus, simple appendix with long main branch curved towards prolateral and shorter retrolateral side-branch ( Figs 71–72 ).

LEGS. Without spines or curved hairs; few vertical hairs; retrolateral trichobothrium on tibia 1 at 3%; prolateral trichobothrium absent on tibia 1, present on other tibiae; tarsus 1 with>30 pseudosegments, only distally about 15 fairly distinct.

Male (variation)

Most males with distinct internal dark marks dorsally and laterally on abdomen. Tibia 1 in 19 other males: 10.9–14.3 (mean 12.3).

Female

In general similar to male but sternum dark brown, eye triads closer together (distance PME-PME 250 µm), without processes between eye triads. Tibia 1 in 16 females: 9.6–11.6 (mean 10.7). Epigynum relatively small, roughly oval plate ( Figs 33 , 75 ) with pair of dark brown areas and anterior ‘knob’ weakly sclerotized in most specimens; entire epigynal area strongly protruding in some specimens; internal genitalia as in Figs 35 and 62 . Spinnerets and spigots as in male ( Fig. 76 ).

Natural history

The spiders were found in partly extremely high densities in a dry brook bed near the road, among rocks and shaded vegetation. The individual domed sheets were interconnected to form large communal webs of up to 2 m length.

Distribution

Known from Baguio area in Luzon 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 50 – 53. Live specimens. 50 – 52. Pholcus baguio Huber, sp. nov., ♁, ♀, and ♀ with egg-sac and emerging juveniles, Mt. Kabuyao. 53. Pholcus arayat Huber, 2011, ♁, Pamulaklakin Forest Trail.

Figs 58 – 62. Pholcus baguio Huber, sp. nov., ZFMK Ar 15507 – 08. 58 – 59. Left male palp, prolateral and retrolateral views. 60. Male chelicerae, frontal view. 61 – 62. Cleared female genitalia, ventral and dorsal views. Scale lines: 58 – 59 = 1 mm; 60 – 62 = 0.5 mm.

Figs 63 – 70. Pholcus baguio Huber, sp. nov., ZFMK Ar 15507. 63. Male prosoma, frontal view. 64. Male ocular area, frontal (slightly dorsal) view. 65 – 66. Male ocular horns and modiFed hairs. 67. Male ocular area, dorsal view. 68. Male left palpal tarsal organ. 69. Right male palpal trochanter and procursus, retrolatero-dorsal view. 70. Left procursus, distal view. Scale lines: 63 = 500 µm; 64 = 300 µm; 65 = 80 µm; 66, 70 = 100 µm; 67, 69 = 200 µm; 68 = 30 µm.

Figs 71 – 76. Pholcus baguio Huber, sp. nov., ZFMK Ar 15507 – 08. 71 – 72. Left genital bulb, prolateral and prolatero-distal views. 73. Male distal cheliceral apophysis (arrows point at modiFed hairs). 74. Male ALS. 75. Epigynum. 76. Female ALS and PMS. Scale lines: 71 – 72, 75 = 200 µm; 73 – 74, 76 = 20 µm.

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