The Southeast Asian Pholcus halabala species group (Araneae, Pholcidae): new data from field observations and ultrastructure

﻿Bernhard A Huber,Amir R.M Ghazali,Joseph K.H Koh,Charles Leh Moi Ung,Booppa Petcharad

doi:10.5852/ejt.2016.190

Abstract

The Southeast Asian Pholcus halabala species group is revised and re-delimited, based mainly on field observations (life color pattern, web design, position of egg-sac when carried by female, microhabitat) and ultrastructure (silk spigots, modifications of male cheliceral apophyses). The core group includes six leafdwelling species that have distinctive color patterns in life specimens (black and white or yellowish abdominal marks, dark pattern on posterior half of carapace) and build round to oval silk platforms on the undersides of leaves. Seven further species are tentatively assigned to the group pending further study. Several species originally assigned to the Pholcus halabala group are transferred to three newly proposed species groups, the Ph. krabi, Ph. buatong, and Ph. andulau groups. Nine species are newly described, four in the Ph. halabala group (Ph. khaolek Huber, sp. nov.; Ph. kuhapimuk Huber, sp. nov.; Ph. lintang Huber, sp. nov.; Ph. ubin Huber, sp. nov.); three in the Ph. krabi group (Ph. kipungit Huber, sp. nov.; Ph. krabi Huber, sp. nov.; Ph. narathiwat Huber, sp. nov.); one in the Ph. buatong group (Ph. buatong Huber, sp. nov.); and one in the Ph. andulau group (Ph. lambir Huber, sp. nov.). The females of Ph. satun Huber, 2011 and Ph. schwendingeri Huber, 2011 (both members of the buatong group) are newly described.

Highlights

With currently over 300 described species, the genus Pholcus Walckenaer, 1805 is by far the most species-rich genus in the Pholcidae (World Spider Catalog 2015)
The Southeast Asian Pholcus halabala species group is revised and re-delimited, based mainly on field observations and ultrastructure
An unrevised genus with more than 300 described and probably hundreds of undescribed species like Pholcus is notoriously difficult to handle: internal relationships are mostly entirely obscure; decisions whether newly collected specimens represent new species or not are difficult or impossible to make; and biological peculiarities cannot be interpreted in an evolutionary context

Summary

Introduction

With currently over 300 described species, the genus Pholcus Walckenaer, 1805 is by far the most species-rich genus in the Pholcidae (World Spider Catalog 2015). It includes some widespread and well-studied synanthropic species such as Ph. phalangioides (Fuesslin, 1775), but most of its diversity is concentrated in the Old World tropics and subtropics. No nomenclature changes were formally proposed, partly because taxonomic sampling in the cladistic analysis seemed too preliminary, partly because some of the 29 species groups proposed seemed non-monophyletic themselves. The main focus of that revision was a first tentative division of this previously chaotic genus into more manageable units, which were explicitly proposed as “operational species groups”

Methods

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Conclusion