Pholcus domingo 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 : 34-39

Pholcus domingo Huber sp. nov.

urn:lsid:zoobank.org:act:DE8B7640-CD1E-469F-B43B-BF319FEB156E

Figs 131–137 , 140–156 , 161–163

Diagnosis

Distinguished from most similar known relative ( P. matutum Huber sp. nov.) by morphology of male palps ( Figs 140–141 ; longer procursus with shorter dorsal process; appendix with long rod-shaped main branch); females of these two species are difficult to separate (internal genitalia relatively shorter in P. matutum Huber sp. nov.; compare Figs 144 and 160 ).

Etymology

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

Material examined

Holotype

PHILIPPINES: ♂, ZFMK ( Ar 15719 ), Mindanao, Bukidnon Prov., Santo Domingo (7.782°N, 125.397°E), 560 m a.s.l., forest remnant along brook, on leaf, 8–9 Feb. 2014 (B.A. Huber, E. Mondejar) .

Other material

PHILIPPINES: 9 ♂♂, 9 ♀♀, 2 juvs, ZFMK ( Ar 15720–21 ) , and 1 ♂, 1 ♀, MSU-IIT, same data as holotype ; 2 ♂♂, 5 ♀♀, in absolute ethanol, same data, ZFMK ( Phi 287 ) ; 1 ♀ with parasitized egg-sac, in absolute ethanol, ZFMK ( Phi 286 ), same data ; 5 ♂♂, 4 ♀♀, 1 juv., ZFMK ( Ar 15722 ), near Santo Domingo , Malangob (7.789°N, 125.384°E), 570 m a.s.l., forest along brook, on leaves, 9 Feb. 2014 (B.A. Huber, E. Mondejar) .

Assigned tentatively

PHILIPPINES, Mindanao: 1 ♂, 1 ♀, ZFMK ( Ar 15723 ), Bukidnon Prov., CEDAR (Center for Ecological Development and Recreation) (8.251°N, 125.034°E), 760 m a.s.l., forest along river, on leaves, 16 Feb. 2014 (B.A. Huber, E. Mondejar) ; 1 ♀, 3 juvs, in absolute ethanol, ZFMK ( Phi 249 ), same data ; 2 ♂♂, 3 ♀♀, 2 juvs, ZFMK ( Ar 15724 ) , and 2 ♂♂, MSU-IIT, same locality, 15 Nov. 2014 (E.P. Mondejar) ; 1 ♂, 3 ♀♀, ZFMK ( Ar 15725 ), Davao del Sur Prov., Malagos Watershed (7.184°N, 125.415°E), 390 m a.s.l., forest along river, on leaves, 14 Feb. 2014 (B.A. Huber, E. Mondejar) ; 1 ♂, 1 ♀, 1 juv. (identity of juvenile uncertain), in absolute ethanol, ZFMK ( Phi 260 ), same data ; 1 ♀, ZFMK ( Ar 15726 ), Davao City, Marilog Distr., Epol Falls, ‘site 1’ (7.456°N, 125.237°E), 1100 m a.s.l., 1 Dec. 2014 (M.A. Responte) ; 1 ♂, ZFMK ( Ar 15727 ), Lanao del Sur Prov., Marawi City, Mt. Mupo (8.018°N, 124.301°E), 20 Nov. 2014 (N.U. Elias) ; 2 ♂♂, 4 ♀♀, 6 juvs, ZFMK ( Ar 15728 ), Maguindanao Prov., Dimapatoy Watershed (7.141°N, 124.202°E), 17 Dec. 2014 (N.U. Elias) .

Description

Male (holotype)

MEASUREMENTS. Total body length 4.5, carapace width 0.9. Leg 1: 35.9 (8.6 + 0.4 + 8.7 + 16.6 + 1.6), tibia 2: 5.4, tibia 3: 3.0, tibia 4: 4.5; tibia 1 L/d: 107. Distance PME-PME 250 µm, diameter PME 100×120 µm, distance PME-ALE ~30 µm; distance AME-AME 40 µm, diameter AME 15 µm.

COLOR. Carapace pale ochre with pair of dark marks near median line posteriorly, ocular area also dark, clypeus pale ochre; sternum grey-brown, with light mark behind labium; legs ochre-yellow with dark brown patellae and tibia-metatarsus joints; abdomen pale ochre-gray with black marks dorsally and laterally, monochromous ventrally except pair of small brown spots in book-lung area.

BODY. Habitus as in Figs 131 and 133 ; ocular area slightly raised, each triad on additional short hump ( Fig. 148 ); carapace without median furrow; clypeus unmodified; sternum wider than long (0.60/0.50), unmodified. Gonopore with four epiandrous spigots ( Fig. 152 ).

CHELICERAE. As in Fig. 142 , barely modified, with indistinct lateral humps proximally, without distal modification, without modified hairs; without stridulatory ridges.

PALPS. As in Figs 140–141 ; coxa unmodified; trochanter with very long curved ventral apophysis; femur with ventral and retrolatero-dorsal processes; tibia very large (relative to femur); procursus rather simple, with strong ventral ‘knee’ and distinctive dorsal process distally ( Fig. 149 ); bulb with long semitransparent embolus and large sclerotized process (putative appendix) densely covered with scales on retrolateral surface ( Figs. 151, 154 ), with lighter prolateral branch proximally ( Fig. 150 ).

LEGS. Without spines and 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>20 pseudosegments, only distally a few fairly distinct. Tarsus 4 comb-hairs as in Fig. 153 .

Male (variation)

Dorsal process of procursus varies considerably among localities: in comparison to males from type locality (Santo Domingo ; Fig. 146 ), it is slightly more slender in male from Malagos; considerably stronger and longer in male from Mt. Mupo ( Fig. 147 ; males from CEDAR intermediate between males from type locality and male from Mt. Mupo); almost absent in males from Dimapatoy ( Fig. 145 ). Male from Mt. Mupo also with slightly different appendix (distal part of sclerotized main branch slightly longer). Males from Dimapatoy with slightly shorter trochanter apophysis. All specimens other than those from Santo Domingo are therefore assigned tentatively to this species. Sternum in most males examined either monochromous whitish or whitish with a few darker marks posteriorly; only one male from Malangob, male from Malagos, and male from Mt. Mupo like holotype; male from Mt. Mupo with more complex carapace pattern ( Fig. 137 ; similar to females from other localities). Tibia 1 in 15 other males: 7.4–9.0 (mean 8.2).

Female

In general similar to male but sternum always dark brown and carapace pattern different: in most females posterior half with light brown to orange pattern ( Fig. 136 ), one female from Dimapatoy with pattern like male holotype. Eye triads slightly closer together than in males (PME-PME distance: 200 µm). Tibia 1 in 19 females: 6.0–7.0 (mean 6.6). Epigynum very simple, weakly sclerotized ( Fig. 161 ), with transverse ridges and finger-shaped posterior ‘knob’ ( Figs 143 , 156 ); internal genitalia as in Figs 144 , 162, 163 . ALS with one large widened, one pointed, and six smaller cylindrically-shaped spigots ( Fig. 155 ). The single female specimen from Epol Falls is assigned tentatively because no males are known from this locality.

Natural history

At Santo Domingo and CEDAR, the spiders were found in very fine, barely visible webs tightly attached to the leaf surface of live leaves about 50–200 cm above the ground. The same kinds of leaves were also occupied by two species of Calapnita , and sometimes a Pholcus and a Calapnita were seen sharing a leaf. When disturbed, the Pholcus just remained still, with their bodies pressed against the leaf; when disturbed with more insistence, they ran away on the leaf or even let themselves down on a silk line. In the egg-sac of one female from the type locality, most eggs were parasitized by a parasitic wasp ( Fig. 132 ).

Distribution

Known from several localities in Mindanao ( Fig. 1 ; but note that specimens from most localities are assigned tentatively).

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 131 – 139. Live specimens and dorsal color patterns, Pholcus domingo group. 131 – 137. Pholcus domingo Huber sp. nov., ♂ and ♀ with parasitized egg-sac from Santo Domingo (131 – 132), habitus of ♂♂ from Santo Domingo (133) and Mt. Mupo (134), and carapace dorsal views, ♂ and ♀ from Santo Domingo (135 – 136) and ♂ from Mt. Mupo (137). 138 – 139. P. matutum Huber sp. nov., Mt. Matutum, ♂ and ♀ with egg-sac.

Figs 140 – 144. Pholcus domingo Huber sp. nov. (ZFMK, Ar 15720 – 21). 140 – 141. Left male palp, prolateral and retrolateral views. 142. Male chelicerae, frontal view. 143 – 144. Cleared female genitalia, ventral and dorsal views. Scale bars: 140 – 141 = 0.5 mm; 142 – 144 = 0.3 mm.

Figs 145 – 147. Pholcus domingo Huber sp. nov., tips of left procursi, retrolateral views. 145. Dimapatoy (ZFMK, Ar 15728). 146. Santo Domingo (type locality) (ZFMK, Ar 15720). 147. Mt. Mupo (ZFMK, Ar 15727). Scale bar = 0.3 mm.

Figs 148 – 156. Pholcus domingo Huber sp. nov., SEM micrographs (ZFMK, Ar 15720 – 21). 148. Male prosoma, frontal view. 149. Tip of left procursus, prolateral view. 150. Left bulb and appendix, prolaterodistal view. 151. Right male palp, retrolatero-distal view. 152. Male gonopore. 153. Comb-hairs on male tarsus 4. 154. Right appendix, retrolateral view. 155. Female ALS. 156. Epigynum, ventral view. Scale bars: 148, 151 = 200 µm; 149 – 150, 156 = 100 µm; 152 = 30 µm; 153, 155 = 10 µm; 154 = 60 µm.

Figs 161 – 166. Epigyna, ventral views, and cleared female genitalia, ventral and dorsal views. 161 – 163. Pholcus domingo Huber sp. nov. (ZFMK, Ar 15721). 164 – 166. P. matutum Huber sp. nov. (ZFMK, Ar 15731).

Figs 157 – 160. Pholcus matutum Huber sp. nov. (ZFMK, Ar 15730 – 31). 157 – 158. Left male palp, prolateral and retrolateral views. 159 – 160. Cleared female genitalia, ventral and dorsal views. Scale bars: 157 – 158 = 0.5 mm; 159 – 160 = 0.3 mm.