Holocnemus Simon 1873
Creators: name: Huber, Bernhard A.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Holocnemus

description: Holocnemus Simon, 1873
Holocnemus Simon, 1873: 48
(type species: Aranea pluchei Scopoli, 1763).
Holocnemus – Simon 1893: 471. — Wiehle 1933: 241.
Remark
Holocnemus is an artificial non-monophyletic group (see Relationships below) that is here maintained for the lack of a convincing better solution. The four included species can be weakly diagnosed by sharing the synapomorphies of the spotted-leg clade (i.e., spotted legs and prolateral hump on the procursus) while maintaining the plesiomorphic long abdomen. A comprehensive description of a nonmonophyletic genus appears of little value. The type species H. pluchei is unique in many ways and may eventually end up in its own monotypic genus. The species description below will thus probably serve the entire genus. For the other three species, I also refer to the redescriptions below.
Relationships
There is strong evidence that the four species currently included in Holocnemus are part of the spotted-leg clade of Smeringopinae, together with the genera Crossopriza, Maghreba gen. nov., and Stygopholcus. Beyond that, however, relationships continue to be obscure. All available evidence suggests that Holocnemus as currently construed is not monophyletic. The cladistic analysis places the type species H. pluchei as sister to all other representatives of the spotted-leg clade, and the other species in a paraphyletic comb (Fig. 1). Support for several of these nodes is weak, however, suggesting that a genomic analysis (in preparation) may well propose a different view of relationships. For that reason, no formal taxonomic changes are implemented here.
Distribution
The type species H. pluchei is widely distributed around the Mediterranean, and has relatively recently expanded towards the north and east and to other continents (Fig. 2). The other three species are restricted to the western Mediterranean: H. reini to northwestern Africa (Fig. 3), H. caudatus and H. hispanicus to the Iberian Peninsula (Figs 3–4).
Natural history
See individual sections on natural history below.
Composition
Currently four nominal species. The species number of this ‘group’ is not likely to change substantially (or not at all) in the future, considering the size of the spiders, their relatively overt life-style (compared to most other Smeringopinae), and their geographic distribution.
Identification key
1. Female with enlarged palps (Figs 29–30), with median process on sternum (Figs 31, 58); male with pair of distinctive processes on distal bulbal sclerite (Figs 24, 26) ......... H. pluchei (Scopoli, 1763)
– Female with regular thin palps, without median process on sternum; males with very different distal bulbal sclerites (Figs 66–68, 139–141) ............................................................................................. 2
2. Sternum in male and female unmodified (i.e., without marginal indentations); male cheliceral apophyses with one modified hair each (Figs 142, 150); procursus ventral sclerite not covered retrolaterally by membrane (Fig. 138); distal bulbal sclerite trapezoidal in prolateral view (Figs 139, 154); epigynum with two long, anteriorly converging pockets (furrows) (Figs 133–134, 162) ........... ................................................................................................................... H. hispanicus Wiehle, 1933
– Sternum in male and female with distinct marginal indentations (Figs 81, 112); male cheliceral apophyses with 2–3 modified hairs each (Figs 64, 82–83, 115); procursus with distinctive retrolateral membrane partly covering ventral sclerite (Figs 63, 117); distal bulbal sclerite triangular in prolateral view (Figs 66, 92); epigynum with pair of pockets in different arrangement (Figs 69, 96, 99, 128) ... ...............................................................................................................................................................3
3. Wide distances between male cheliceral apophyses (70–80% of cheliceral maximum width) and between female epigynal pockets (> 0.5 mm) .......................... H. reini comb. nov. (C. Koch, 1873)
– Small distances between male cheliceral apophyses (50–60% of cheliceral maximum width) and between female epigynal pockets (<0.4 mm) ....................................... H. caudatus (Dufour, 1820)
description: Published as part of Huber, Bernhard A., 2022, Revisions of Holocnemus and Crossopriza: the spotted-leg clade of Smeringopinae (Araneae, Pholcidae), pp. 1-241 in European Journal of Taxonomy 795 (1) on pages 7-9, DOI: 10.5852/ejt.2022.795.1663, http://zenodo.org/record/6299150