Pholcus ethagala

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 : 4-5

Pholcus ethagala species group

Diagnosis

This group (proposed in Huber 2011) includes medium-sized, long-legged spiders (body length ~3.0– 4.5, male leg 1 length:~30–40); distinguished from similar species groups in Pholcus ( P. minang and P. kerinci groups proposed in Huber 2011, and P. buatong group proposed in Huber et al. 2016) by combination of following characters: elongate abdomen slightly angular or pointed dorso-posteriorly ( Figs 5 , 32 ); six eyes (in contrast to P. kerinci group; only the dubious P. vesculus Simon, 1901 with eight eyes); male eye triads on stalks ( Figs 39 , 48 , 77–80 ; in contrast to P. kerinci group); male chelicerae with distinct proximal apophyses in frontal position ( Figs 12 , 17 , 69 , 74 ; in contrast to P. kerinci and P. buatong groups), without distal apophyses (in contrast to P. minang group); male palpal trochanter with short retrolateral apophysis and longer to very long ventral apophyses ( Figs 11 , 16 , 68 , 73 ; short only in P. gombak Huber, 2011 ); male palpal patella dorsally not bulging (in contrast to P. buatong group); palpal tarsus with dorsal elongation ( Figs 11 , 68 ; except P. phui Huber, 2011 and P. barisan Huber sp. nov.), bulb with large and often complex appendix and weakly sclerotized embolus, without uncus; procursus highly complex, with dorsal (sometimes rather prolateral) process and hinged distal element; epigynum weakly sclerotized, with small ‘knob’ ( Figs 13 , 18 , 70 , 75 ; in contrast to P. buatong group).

Description – amendments

The original description ( Huber 2011) is still largely valid. The following can be added: clypeus usually unmodified but with pair of small processes in P. barisan Huber sp. nov. ( Fig. 80 ); male palpal femur ventrally very variable, from barely modified ( P. barisan Huber sp. nov.; Fig. 73 ) to distinct processes ( P. ethagala Huber, 2011 ; P. phui Huber, 2011 ; P. ledang Huber, 2011 ; P. gombak Huber, 2011 ). Genital bulb without uncus but in some species with small sclerite that originates from proximal bulbal sclerite (arrows in Figs 15 , 25 , 67 ) and might be homologous to the uncus present in most other Pholcus groups.

Tibia 1 in males 6–10; tibia 1 L/d ~80–105; tibia 2/tibia 4 usually about 1.05–1.15, in P. uludong Huber sp. nov. 1.00. Male gonopore usually with four epiandrous spigots ( Figs 46 , 57 ; the three spigots in the specimen figured in Huber 2011: fig. 803 is probably an individual exception). Tarsus 4 comb-hairs of the simplified Pholcus - type (cf. Huber & Fleckenstein 2008), with four lateral tines ( Figs 28 , 50 ).

Composition

The P. ethagala group now includes ten species: two species on Sri Lanka ( P. ethagala ; P. maturata Huber, 2011 ), seven species on the Malay Peninsula ( P. phui ; P. vesculus ; P. tanahrata Huber sp. nov.; P. uludong Huber sp. nov; P. gombak ; P. ledang ; P. bukittimah Huber sp. nov.) and one species on Sumatra ( P. barisan Huber sp. nov.). The poorly known P. vesculus is assigned tentatively and probably misplaced (see Huber 2011). Originally, P. schwendingeri Huber, 2011 was also assigned tentatively to this group; it has recently been transferred to the newly created P. buatong group ( Huber et al. 2016).

Natural history

The seven species newly observed in the field (Malay Peninsula and Sumatra) were mostly found on the undersides of large dead leaves on the ground. This is in contrast to the two Sri Lankan species that supposedly live on live leaves (at least P. ethagala ; Huber 2011). Very few specimens of the newly observed species were also found under logs ( P. ledang ) and in bamboo sheaths and under rocks ( P. gombak ). The availability of suitable large leaves on the forest floor strongly influenced spider abundance. Webs consisted of small domed sheets closely attached to the leaf surface. When disturbed, the spiders barely reacted; they vibrated only for a short time at low amplitude or were not seen to vibrate at all. Two egg-sacs (of two species) were parasitized by Idris Foerster, 1856 ( Scelionidae , Baeini ) wasps ( Figs 33–35 , 62 ). For further information see individual descriptions below.

Distribution

The P. ethagala group is known from Sri Lanka (see Huber 2011; not treated herein and not shown in Fig. 1 ) and from Southeast Asia (Malay Peninsula, Sumatra; 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 2 – 9. Live specimens. 2 – 3. Pholcus phui Huber, 2011, Hala Bala, ♂ and ♀ with egg-sac. 4 – 7. P. tanahrata Huber sp. nov., Cameron Highlands, ♂, penultimate ♂, and ♀. 8 – 9. P. uludong Huber sp. nov., Ulu Dong, ♂ and ♀.

Figs 32 – 38. Live specimens. 32 – 35. Pholcus gombak Huber, 2011, Kemensah (32) and Gunung Liang (33 – 35), ♂, ♀ with parasitized egg-sac seven days before eclosion of wasps (33), one day before eclosion (34), and at eclosion (35). 36 – 38. P. ledang Huber, 2011, Gunung Ledang, ♂ and ♀ with egg-sac.

Figs 39 – 47. Pholcus gombak Huber, 2011, SEM micrographs (ZFMK, Ar 15701 – 02). 39 – 40. Male and female prosomata, frontal views. 41. Left procursus; asterisk marks large prolatero-dorsal process. 42 – 43. Right appendix and embolus, prolateral and prolatero-distal views. 44. Female ALS. 45. Cuticular processes on whitish retrolateral area of left procursus. 46. Male gonopore. 47. Epigynum, ventral view. Scale bars: 39 – 40 = 300 µm; 41, 47 = 200 µm; 42, 43 = 100 µm; 44 = 20 µm; 45 = 10 µm; 46 = 30 µm.

Figs 48 – 53. Pholcus ledang Huber, 2011, SEM micrographs (ZFMK, Ar 15704 – 05). 48 – 49. Male and female prosomata, frontal views. 50. Comb hairs on male tarsus 4. 51 – 52. Right appendix and embolus, prolateral and distal views. 53. Female ALS. Scale bars: 48 = 300 µm; 49 = 200 µm; 50 = 10 µm; 51 – 52 = 100 µm; 53 = 20 µm.

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.

Figs 10 – 14. Pholcus tanahrata Huber sp. nov. (ZFMK, Ar 15692). 10 – 11. Left male palp, prolateral and retrolateral views. 12. Male chelicerae, frontal view. 13 – 14. Cleared female genitalia, ventral and dorsal views. Scale bars: 10 – 11, 13 – 14 = 0.5 mm; 12 = 0.3 mm.

Figs 15 – 19. Pholcus uludong Huber sp. nov. (ZFMK, Ar 15695 – 96). 15 – 16. Left male palp, prolateral and retrolateral views; arrow points at uncus-like process of proximal bulbal sclerite. 17. Male chelicerae, frontal view. 18 – 19. Cleared female genitalia, ventral and dorsal views. Scale bars: 15 – 16, 18 – 19 = 0.5 mm; 17 = 0.3 mm.

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 72 – 76. Pholcus barisan Huber sp. nov. (ZFMK, Ar 15708 – 09). 72 – 73. Left male palp, prolateral and retrolateral views. 74. Male chelicerae, frontal view. 75 – 76. Cleared female genitalia, ventral and dorsal views. Scale bars: 72 – 73, 75 – 76 = 0.5 mm; 74 = 0.3 mm.

Figs 20 – 25. Pholcus uludong Huber sp. nov., SEM micrographs (ZFMK, Ar 15695 – 96). 20 – 21. Male and female prosomata, frontal views. 22. Right male palp, retrolateral view. 23. Right procursus and bulb, dorsal view. 24 – 25. Left bulb with appendix and embolus, prolateral and prolatero-dorsal views; arrow points at uncus-like process of proximal bulbal sclerite. Scale bars: 20, 22 = 300 µm; 21, 23 = 200 µm; 24 – 25 = 100 µm.

Figs 54 – 58. Pholcus ledang Huber, 2011, SEM micrographs (ZFMK, Ar 15704 – 05). 54. Left procursus, retrolateral view. 55. Right procursus, distal view. 56. Cuticular processes on whitish retrolateral area of left procursus. 57. Male gonopore. 58. Epigynum, ventral view. Scale bars: 54, 58 = 200 µm; 55 = 100 µm; 56 = 10 µm; 57 = 30 µm.

Figs 26 – 31. Pholcus uludong Huber sp. nov., SEM micrographs (ZFMK, Ar 15695 – 96). 26. Male ocular area, dorsal view. 27. Dorsal process of right procursus. 28. Comb-hairs on male tarsus 4. 29 – 30. Male and female ALS. 31. Epigynum, ventral view. Scale bars: 26, 31 = 200 µm; 27 = 60 µm; 28 – 30 = 20 µm.

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.