Pholcus andulau

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 : 47

Pholcus andulau species group

This species group is newly proposed to include one species previously included in the Ph. halabala group ( Ph. andulau Huber, 2011 ) and the newly described Ph. lambir Huber , sp. nov. They share three putative synapomorphies: (1) the unique, partly sclerotized embolus with strong sclerotized pointed processes ( Figs 200 , 209–212 ); (2) pointed male cheliceral apophyses directed toward each other and without modified hairs ( Figs 202 , 214 ); and (3) large unsclerotized ‘knob’ on female external genitalia directed toward anterior ( Figs 203 , 213 ). The two species are also otherwise very similar (females are indistinguishable in the field; Ph. lambir sp. nov. males have a darker ocular area than Ph. andulau males) and restricted to a limited geographic area in northern Borneo ( Fig. 153 ). Preliminary molecular data (A. Valdez-Mondragón, B.A. Huber & D. Dimitrov unpublished data) suggest a close relationship with the Panjange nigrifrons group (which is also restricted to Borneo), but we know of no putative morphological synapomorphy that would support this relationship. However, general habitus and coloration are almost identical, and the same is true of web structure and microhabitat: in both groups, the spiders build domed webs among the vegetation, with the apex of the sheet connected to the underside of a leaf. In addition, they hang in their webs under the leaf rather than having their bodies pressed against the leaf, and in both groups, cecidomyiid flies were often seen in large numbers hanging in the spider webs. When disturbed, Pholcus andulau and Ph. lambir sp. nov. vibrate vigorously. Egg-sacs are carried in front of the body ( Figs 194, 196 ), as in typical pholcids.

Figures

Fig. 153. Known distributions of the Pholcus buatong species group (Malay Peninsula) and of the Pholcus andulau species group (northern Borneo).

Figs 200 – 204. Pholcus lambir Huber, sp. nov., ZFMK Ar 15060 – 61. 200 – 201. Left male palp, prolateral and retrolateral views. 202. Male chelicerae, frontal view. 203 – 204. Cleared female genitalia, ventral and dorsal views. Abbreviations: b = genital bulb; e = embolus; p = procursus; u = uncus. Scale lines: 0.3 mm (202 – 204), 0.5 mm (200 – 201).

Figs 205 – 210. Pholcus lambir Huber, sp. nov., ZFMK Ar 15060 – 61. 205 – 206. Male and female prosomata, frontal views. 207. Right procursus, retrolateral (slightly dorsal) view. 208. Left procursus (and genital bulb), prolateral view. 209. Right procursus (and embolus sclerite), distal view. 210. Right embolus sclerite, prolateral view. Abbreviations: b = genital bulb; e = embolus; p = procursus. Scale lines: 50 µm (210); 100 µm (207 – 209); 200 µm (205 – 206).

Figs 211 – 218. Pholcus lambir Huber, sp. nov., ZFMK Ar 15060 – 61. 211 – 212. Left bulbal processes, prolateral (slightly distal) and ventral views (arrows point at sperm duct opening). 213. Epigynum, ventral view. 214. Distal male cheliceral apophyses. 215. Comb-hairs on male tarsus 4. 216. Male gonopore. 217 – 218. Female and male ALS. Abbreviations: e = embolus; u = uncus. Scale lines: 10 µm (215, 218); 20 µm (217); 30 µm (214, 216); 60 µm (211); 80 µm (212); 200 µm (213).

Figs 193 – 199. Live specimens, Pholcus andulau group, and female genitalia of Ph. lambir Huber, sp. nov. 193 – 194. Pholcus andulau Huber, 2011, ♂ and ♀ with egg-sac from Gunung Mulu, Sarawak. 195 – 196. Ph. lambir sp. nov., ♂ and ♀ with egg-sac from Lambir, Sarawak. 197 – 199. Ph. lambir sp. nov., female genitalia, untreated in ventral view, cleared in ventral and dorsal views.