Pholcus krabi

Berhard A. Huber, Booppa Petchard, Charles Leh Moi Ung, Joseph K. H. Koh & Amir R. M. Ghazali, 2016, The Southeast Asian Pholcus halabala species group (Araneae, Pholcidae): new data from field observations and ultrastructure, European Journal of Taxonomy 190, pp. 1-55 : 27

Pholcus krabi species group

This species group is newly proposed to include three species previously part of the Ph. halabala group ( Ph. chiangdao Huber, 2011 ; Ph. khene Huber, 2011 ; Ph. kinabalu Huber, 2011 ) as well as three newly described species ( Ph. krabi Huber , sp. nov.; Ph. narathiwat Huber , sp. nov.; Ph. kipungit Huber , sp. nov.). They share three putative synapomorphies: (1) absence of AME ( Figs 116–117 ); (2) absence of modified hairs on distal male cheliceral apophyses ( Fig. 118 ); and (3) reduction of ALS spigots to two (one widened, one pointed; Fig. 122 ; confirmed in Ph. kinabalu and Ph. krabi sp. nov. only). In addition, live males of the three newly described species share highly distinctive reddish to orange palps ( Figs 102, 106, 108 ), and females of at least Ph. chiangdao , Ph. kinabalu , and Ph. narathiwat sp. nov. share dimorphic color patterns on the prosoma. Species newly observed in the field ( Ph. kipungit sp. nov.; Ph. narathiwat sp. nov.; Ph. krabi sp. nov.) built very similar domed webs among the vegetation (0.5–2 m above the ground), usually with the apex of the dome attached to the underside of a leaf. They are also very similar in general appearance (the three species are indistinguishable in the field; Figs 102–109 ). Very low abundances and/or patchy distributions were observed in all three species. However, most specimens known of Ph. kinabalu were collected by canopy fogging ( Huber 2011), suggesting that abundances of at least this species may be different in higher forest strata. Egg-sacs are carried in front of the body ( Figs 105, 109 ) as in typical pholcids. This species group is known from mainland Southeast Asia and Borneo ( Fig. 110 ). The RMNH has an additional species from East Kalimantan ( Fig. 110 ) that is not described here because only a single poorly preserved male specimen is available.

Figures

Fig. 110. Known distribution of the Pholcus krabi species group.

Figs 116 – 123. Pholcus krabi Huber, sp. nov., ZFMK Ar 15038 – 39. 116 – 117. Male and female prosomata, frontal views. 118. Male distal cheliceral apophysis. 119. Left male palp, dorsal view. 120. Left procursus (and trochanter apophysis), retrolateral view. 121. Right bulbal processes, prolateral (slightly ventral) view. 122. Male ALS. 123. Comb-hairs on male tarsus 4. Abbreviations: a = appendix; b = genital bulb; e = embolus; f = femur; p = procursus; tr = trochanter; u = uncus. Scale lines: 8 µm (123); 10 µm (118, 122); 80 µm (121); 100 µm (120); 200 µm (116 – 117, 119).

Figs 102 – 109. Live specimens, Pholcus krabi Huber, sp. nov. (102 – 105), Ph. narathiwat Huber, sp. nov. (106 – 107), and Ph. kipungit Huber, sp. nov. (108 – 109). 102 – 104. ♂ and ♀ from Khao Sok, Thailand. 105. ♀ with egg-sac from Phanom Bencha, Thailand. 106 – 107. ♂ and ♀ from Hala Bala, Thailand. 108 – 109. ♂ and ♀ from Poring, Sabah.