Holocnemus Simon, 1873

Huber, Bernhard A., 2022, Revisions of Holocnemus and Crossopriza: the spotted-leg clade of Smeringopinae (Araneae, Pholcidae), European Journal of Taxonomy 795 (1), pp. 1-241 : 7-9

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)

Figures

Fig. 1. Single most parsimonious cladogram of the spotted-leg clade resulting from analyses of the matrix in Appendix 1 using equal character weights and successive character weighting. Only unambigous character changes are shown. See Appendix 3 for differences in analyses using implied character weighting with conc =1 and 2.

Fig. 2. Known distribution of Holocnemus pluchei (Scopoli, 1763), with approximate decades in which the species appeared in North America, South America, Central Europe, Australia, and Japan; see Distribution section for details.

Fig. 3. Known distributions of Holocnemus reini (C. Koch, 1873) comb. nov. and H. caudatus (Dufour, 1820). Light blue: dubious records; see Distribution section for details. Abbreviation: TL = type localities (the type locality of H. reini is not exactly known; see text for details).

Figs 29–35. Holocnemus pluchei (Scopoli, 1763). 29–30. Female from Georgia, Sighnaghi (ZFMK Ar 21373); left palp, prolateral and retrolateral views. 31. Female from Georgia, Sighnaghi (ZFMK Ar 21373); sternum, ventral (slightly frontal) view; arrow: posterior process. 32–33. Female and male from Bulgaria, Blagoevgrad (SMF), showing modified female pedicel and pair of plates frontally on female abdomen (arrows). 34. Female from Israel, Mount Karmel (ZFMK Ar 22305); left femur 3 ventral view. 35. Female from Israel, S of Teverya (ZFMK Ar 22306); female tarsus, showing irregular pseudosegmentation. Scale bars: 29–33 = 0.5 mm; 34 = 0.2 mm; 35 = 0.1 mm.

Figs 51–58. Holocnemus pluchei (Scopoli, 1763); male and female from Greece, Daphni/Athens (MHNG). 51–52. Male and female palpal tarsal organs.53. Tarsal organ on male tarsus 4. 54. Tip of male cheliceral apophysis. 55. Male gonopore. 56. Male spinnerets. 57. Epigynum and anterior abdominal process (arrow).58. Female sternum, showing posterior process (arrow). Scale bars: 51–54, 56 = 10 µm; 55 = 20 µm; 57–58 = 100 µm.

Figs 20–28. Holocnemus pluchei (Scopoli, 1763); male from Israel, S of Teverya (ZFMK Ar 22306), female from Georgia, Sighnaghi (ZFMK Ar 21373). 20–22. Left procursus, prolateral, dorsal, and retrolateral views; arrow: prolateral-ventral process. 23–26. Left genital bulb, ventral, prolateral, dorsal, and retrolateral views. 27–28. Cleared female genitalia, ventral and dorsal views; arrow: pair of sculptured areas; asterisks: pair of internal pockets. Abbreviations: bs = basal sclerite; ds = distal sclerite; vs = ventral sclerite. Scale bars: 20–26 = 0.3 mm; 27–28 = 0.5 mm.

Figs 62–70. Holocnemus reini (C. Koch, 1873) comb. nov.; male from Morocco, near Tilamizene (ZFMK Ar 22319), female from Morocco, Al Kamoun (CAS 9027140). 62–63. Left procursus, prolateral and retrolateral views; arrow: retrolateral membrane. 64–65. Male chelicerae, frontal and lateral views. 66–68. Left genital bulb, prolateral, dorsal, and retrolateral views; arrow: sperm duct opening. 69–70. Cleared female genitalia, ventral and dorsal views; arrows: pockets. Abbreviations: bs = basal sclerite; ds = distal sclerite; vs = ventral sclerite. Scale bars: 62–63, 66–68 = 0.3 mm; 64–65, 69–70 = 0.5 mm.

Figs 136–145. Holocnemus hispanicus Wiehle, 1933; male from Spain, Cáceres, Conquista de la Sierra (CRB), female from Spain, Málaga, Ronda (CRB). 136–138. Left procursus, prolateral, dorsal, and retrolateral views; arrow: prolateral transparent process. 139–141. Left genital bulb, prolateral, dorsal, and retrolateral views. 142–143. Male chelicerae, frontal and lateral views. 144–145. Cleared female genitalia, ventral and dorsal views; arrows: pockets. Abbreviations: bs = basal sclerite; ds = distal sclerite; vs = ventral sclerite. Scale bars = 0.3 mm.

Figs 146–154. Holocnemus hispanicus Wiehle, 1933; male and female from Spain, Huelva, “Alájar/ Aracena” (MHNG). 146. Male ocular area. 147. Male clypeus. 148. Female carapace and ocular area. 149. Male cheliceral stridulatory file. 150. Tip of male cheliceral apophysis. 151. Female cheliceral stridulatory file. 152. Stridulatory pick on female palpal femur. 153. Left procursus, retrolateral-ventral view. 154. Distal (main) sclerite of left genital bulb, prolateral (slightly distal) view; arrow: sperm duct opening. Abbreviation: vs = ventral sclerite. Scale bars: 146–148, 154 = 100 µm; 149, 151, 153 = 20 µm; 150, 152 = 10 µm.

Figs 129–135. Holocnemus hispanicus Wiehle, 1933. 129–131. Male from Spain, Cáceres, Conquista de la Sierra (CRB); left palp, prolateral, dorsal, and retrolateral views. 132. Female from Spain, Málaga, Ronda (CRB); abdomen, ventral view. 133. Female from Spain, Granada, “Sierra Havana” (SMF 8802); epigynum, ventral view. 134. Female from Spain, Málaga, between Periana and Ventas Zafarrayas (ZFMK Ar 23862); epigynum, ventral view. 135. Female from Spain, Badajoz, SW of Zafra (CRB); detail of female left femora 3 and 4, retrolateral-ventral view. Scale bars: 129–134 = 0.5 mm; 135 = 0.2 mm.

Figs 155–162. Holocnemus hispanicus Wiehle, 1933; male and female from Spain, Huelva, “Alájar/ Aracena” (MHNG). 155. Male palpal tarsal organ. 156. Tarsal organ on male tarsus 3. 157. Tip of male right tarsus 4, showing comb-hairs. 158. Tip of female palp with tarsal organ. 159. Male ALS. 160. Female spinnerets. 161. Male gonopore. 162. Epigynum; arrows: pockets. Scale bars: 155–160 = 10 µm; 161 = 20 µm; 162= 100 µm.

Figs 81–88. Holocnemus reini (C. Koch, 1873) comb. nov.; male and female from Morocco, near Tilamizene (ZFMK Ar 22319). 81. Female sternum; arrows: indentations. 82–83. Modified hairs on male cheliceral apophyses (from same specimen). 84–85. Male and female cheliceral stridulatory files. 86. Stridulatory pick on male palpal femur. 87–88. Male and female palpal tarsal organs. Scale bars: 81 = 100 µm; 82–83, 86–88 = 10 µm; 84–85 = 20 µm.

Figs 111–118. Holocnemus caudatus (Dufour, 1820); male and female from Spain, Granada, Trevélez (MHNG). 111. Female ocular area. 112. Male sternum; arrows: indentations. 113–114. Male and female cheliceral stridulatory files. 115. Modified hairs on male cheliceral apophysis. 116. Stridulatory pick on male palpal femur. 117. Right procursus tip, prolateral view; arrow: retrolateral membrane. 118. Male gonopore. Abbreviation: vs = ventral sclerite. Scale bars: 111–112, 117–118 = 100 µm; 113–114 = 20 µm; 115–116 = 10 µm.

Figs 89–96. Holocnemus reini (C. Koch, 1873) comb. nov.; male and female from Morocco, near Tilamizene (ZFMK Ar 22319). 89–91. Tips of right (89) and left (90–91) procursi, retrolateral and slightly distal views; arrow: retrolateral membrane. 92. Left genital bulb, prolateral view; arrow: sperm duct opening. 93. Male gonopore. 94. Male ALS.95. Female spinnerets. 96. Epigynum; arrows: pockets. Scale bars: 89, 93 = 20 µm; 90–91, 94–95 = 10 µm; 92, 96 = 100 µm.

Figs 97–100. Holocnemus caudatus (Dufour, 1820); male and female from Spain, Valencia, Montroy (MHNG). 97–98. Male chelicerae, frontal and lateral views. 99–100. Cleared female genitalia, ventral and dorsal views; arrows: pockets. Scale bars = 0.3 mm.

Figs 119–128. Holocnemus caudatus (Dufour, 1820); male and female from Spain, Granada, Trevélez (MHNG). 119. ‘Short vertical hair’ on male metatarsus 4. 120. Tip of hair from preceding figure. 121. Male palpal tarsal organ. 122–123. Tarsal organs on male tarsi 1 and 4. 124. Female palpal tarsal organ. 125–126. Male and female spinnerets. 127–128. Epigyna and anterior epigynal humps (arrows). Scale bars: 119, 121–125 = 10 µm; 120 = 1 µm; 126 = 20 µm; 127–128 = 100 µm.