Walckenaer (1802) divided spiders into 18 “Famillies.” At this time, concepts of nomenclature were distinctly different from our modern understanding. All spider species were referred to by a binomen with “Aranea” as the genus regardless of “famillie” placement. Chercheuses (Erraticae) contained one species: Aranea cinnaberina (now Eresus kollari). Because Walckenaer’s family name was not formed from the stem name of the type genus, it was not considered valid once international codes of nomenclature were adopted starting in 1905 (International Commission on Zoological Nomenclature 1905). For an enlightening discussion of Walckenaer’s and related systems of spider classification, see Edwards (2011).

Distinguished from other three-clawed, eight-eyed, cribellate entelegyne spiders except Penestomidae by their subrectangular carapace and clypeal hood; distinguished from Penestomidae by the absence of an RTA on the male palpal tibia, the absence of a median apophysis arising from the palpal tegulum, the absence of a posterior lobe of the epigynum (the posterior lobe is a separate plate in Penestomidae; compare Figs 45A, 93A with Miller et al. 2010b: fig. 8A), and the absence of a tapetum in the indirect eyes. The eye arrangement in Eresidae is distinctive, with a straight anterior eye row and strongly recurved posterior eye row, with the median eyes close together, the ALE near the anterior lateral corners of the carapace, and the PLE position on the carapace at least 0.2 (Figs 8B, D, F, H, J, L, 9B, D, F, H, J, L, 10 B, D, F, H, J, L, 11B, D, F, H, J, L); by contrast, Penestomidae have the anterior eyes subequally spaced with the ALE placed about midway between the center and the corners of the carapace (Miller et al. 2010b: fig. 1C), and the PLE position on the carapace ca. 0.1.

Somatic morphology:Carapace subrectangular in dorsal view; cephalic region may be strongly raised. Eight eyes in two rows, posterior eye row strongly recurved so that the PLE are set far back from the others (Figs 8B, D, F, H, J, L, 9B, D, F, H, J, L, 10 B, D, F, H, J, L, 11B, D, F, H, J, L). Tapetum absent from eyes. The anterior-median part of carapace extended ventrally into a clypeal hood (Figs 8A, C, E, G, I, K, 9A, C, E, G, I, K, 10A, C, E, G, I, K, 11A, C, E, G, I, K). Two or more setal morphologies typically present appearing as dark and white setae in museum specimens (Figs 35B, 81D, 91B). Chelicerae robust, may be contiguous (Fig. 19G) or excavated mesally (Fig. 68F), distal anterior part with dense cluster of strong setae near fang (Fig. 28C), usually with boss (Figs 28B, 46B, 56E, but see 56C); large single keel anterior to fang, may be serrate, with series of small denticles leading towards base of fang; there is no distinct fang furrow (Figs 34F, 91F). Female palp with tarsal claw (Fig. 92F). Legs usually short with two rows of trichobothria on tibiae and one distal trichobothrium on metatarsi. Bothria have series of transverse grooves proximally (Figs 25D, 38B, 45E, 92B). Tarsal organ small, capsulate, and positioned near the distal tip (Figs 38A, 46D, 92A). Major and median claws with series of teeth (Figs 38C, 92C). Linear calamistrum occupies entire length of metatarsus IV (Figs 25E, 38D, 46E, 92D), with a dorsal patch of smaller calamistral setae (i.e., with lines of teeth, Figs 25F, 31F, 38E, 46F, 67F, 82F, 92E). In some eresids, the line of primary calamistrum setae is not clearly distinguishable from the dorsal patch (Figs 25F, 31F, 46F, 67F). Abdomen generally oblong with distinct dorsal sigilla (Figs 3I, 4H, 19A, 47I, 89E). Posterior respiratory system comprises four simple tracheal tubes (Lamy 1902; CEG, pers. obs. Stegodyphus and Dresserus).

Male palp: Male palpal tibia without apophysis, with two rows of trichobothria (Figs 27F, 34E, 55F). Palpal bulb with sclerotized conductor that interacts with spiral embolus (Figs 27C, 34D, 41F, 90D), expansion occurs in both the basal and median haematodochae (Figs 12F, 13C, F, 15C, L). Axis of spiral typically proximal-distal with embolus encircling distal part (Figs 12B, 13B, H, J, 14I, 15B, H, K), occasionally more or less ventral-dorsal with embolus encircling ventral part (Dresserus and Gandanameno; Figs 12G, 13D, 33I–K, 48A–F).

Figure 12.

A–L Left male palpi of eresid species, photomicrographs. A–C Adonea fimbriata from Algeria-Morocco (MR012, MR) D–F Dorceus fastuosus from Mashabin Sand Dunes, Israel (MR006, HUJ) G–I Dresserus sp. from Manga Forest Reserve, Tanzania J–L Eresus walckenaeri from Leptokaryas, Greece (MR020, MR) A, D, G, J prolateral view B, E, K retrolateral view H ventral view C, F, I, L expanded palp. BH basal haematodocha MH median haematodocha.

Figure 13.

A–L Left male palpi of eresid species, photomicrographs. A–C Eresus kollari from res. Radotinske udoli, Czechia (MR007, MR) D–F Gandanameno sp. from Van Riebeeck Park, Western Cape, South Africa (CASENT 9023763, CAS) G–I Loureedia annulipes from Haluqim Ridge, Israel (PET03, MR) J, K Paradonea striatipes from Otjivasandu (NMN), Namibia L Paradonea splendens from Sunnyside, South Africa (C1076, SAM) A, D, G, J, L prolateral view B, H, K retrolateral view E ventral view C, F, I expanded palp. BH basal haematodocha MH median haematodocha.

Figure 14.

A–L Left male palpi of Paradonea species, photomicrographs. A Paradonea splendens from Sunnyside, South Africa (C1076, SAM) B, C Paradonea variegata from Breekkierie Dunes, Northern Cape, South Africa (C1062, SAM) D–I Paradonea parva D–F holotype from junction of Marico and Crocodile Rivers, South Africa (B3701, SAM) G–I from 4 km N of Hopetown, Northern Cape, South Africa (AcAT 97/988, NCA) J–L Paradonea presleyi sp. n. holotype from Falcon College, Zimbabwe (CASENT 9039236, CAS) A, C, F, I, L retrolateral view B, D, G, J prolateral view E, H, K ventral view.

Figure 15.

A–L Left male palpi of eresid species, photomicrographs. A–C Seothyra henscheli from Gobabeb Station, Namibia (SMN 40828, NMN) D, F Stegodyphus lineatus D–E from Negev, Israel (MR) F from Nengrahar, Afghanistan (MR010, MR) G–I Stegodyphus mimosarum from Forêt d'Analalava, Fianarantsoa, Madagascar (CASENT 9015950, CAS) J–L Stegodyphus sarasinorum from 7.5 km E PwintPhyu, Magway Division, Myanmar (CASENT 9019370, CAS) A, D, G, J prolateral view B, E, H, K retrolateral view C, F, I, L expanded palp. BH basal haematodocha MH median haematodocha.

Figure 16.

A–L Epigyna of eresid species, photomicrographs. A, D Adonea fimbriata; A from Mehav Am village, Israel (MR003, MR) D from Wadi Mashash, Israel (MR013, HUJ) B, E Dorceus fastuosus from Mashabim sand dunes, Israel (MR002, MR) C, F Dresserus sp. from Klein Kariba, South Africa (CASENT 9025745, CAS) G, J Eresus walckenaeri from 5 km south of Monemvasia, Lakonia, Greece (ZMUC 00012903, ZMUC) H, K Eresus kollari from res. Radotinske udoli, Czechia (MR016, MR) I, L Eresus sandaliatus from SE of Silkeborg, Denmark (CASENT 9039243, CAS) A–C, G–I ventral viewD–F, J–L dorsal view, cleared. CD copulatory duct ML median lobe S spermatheca SH spermathecal head.

Female genitalia: Epigynum present with entelegyne configuration, one pair of spermathecae (typically in a posterior position except in Dresserus and Gandanameno, where they are anterior), and spermathecal heads (typically in an anterior position and far from the spermathecae except in Dresserus and Gandanameno, where they are adjacent to the spermathecae; Figs 16D–F, J–L, 17D–F, 18D–F, J–L, 22B, 29D, 37E, 42D, 45B, 59C, 65B, 76B, 82B, 86B, 93B); posterior lobe absent (compare Figs 45A, 93A with Miller et al. 2010b: fig. 8A).

Figure 17.

A–F Epigyna of Gandanameno sp., photomicrographs. A, D from Iringa, Tanzania (ZMUC 19970517, ZMUC) B, E from Kommetjie, Western Cape, South Africa (CASENT 9039241, CAS), note broken embolus left in female reproductive system C, F from Port Elizabeth, South Africa (port-3325, ZMHB) A–C ventral view D–F dorsal view, cleared. CD copulatory duct S spermatheca SH spermathecal head.

Figure 18.

A–L Epigyna of eresid species, photomicrographs. A, D Loureedia annulipes from Wadi Mashash, Negev, Israel (MR019, MR) B, E Paradonea variegata from Steinkopf, Northern Cape, South Africa (ZMB 26964, ZMHB) C, F Seothyra henscheli; C from Kuiseb River, Gobabeb, Namibia (SMN 46627, NMN) F from Sout Rivier, Namibia (CASENT 9039242, CAS) G, J Stegodyphus lineatus from Belkis, near Birecor, Turkey (MR015, MR) H, K Stegodyphus mimosarum H from Forêt d'Analalava, Fianarantsoa, Madagascar (CASENT 9015950, CAS) K from Réserve Spéciale de Cap Sainte Marie, Toliara, Madagascar (CASENT 9012844, CAS) I, L Stegodyphus sarasinorum from 7.5 km E PwintPhyu, Magway Division, Myanmar (CASENT 9019370, CAS) A–C, G–I ventral view D–F, J–L dorsal view, cleared. AL anterior lobe ML median lobe S spermatheca SH spermathecal head.

Spinneret spigot morphology: ALS typically with multiple MAP (absent in Seothyra, Figs 77B, 78B) and a field of PI (Figs 36B, 94B). PMS with one to several mAP and a field of AC, occasionally elongated and divided into two lobes (female Dresserus and Gandanameno, Figs 36C, 57A, C), CY present (Figs 36C–D, 57C, 58E) or uncertain. PLS with field of AC, MS positioned on dorsal part adjacent to ALS far from rest of field, may be accompanied by one (Dorceus, Figs 30F, 32F) or two (Eresus sandaliatus group, Loureedia gen. n., Seothyra, Stegodyphus, Figs 67D, 87D, 95E) flanking AC (no MS-flanking AC in at least Dresserus and Gandanameno, Figs 36E, 57D, 58C, 61B–C). Cribellum present with median division in most genera (Figs 57E, 77E, 87A, 94A, E), each half subdivided in Dresserus (Fig. 36F). Multiple epiandrous gland spigots present in male (Figs 22E–F, 28D, 39F, 45F, 61E–F, 65F, 74E–F, 80E–F, 85E–F, 93F).

Our phylogenetic analysis is a modest expansion of Miller et al. (2010a) and the topology is congruent with the earlier study. The additions to the new analysis are two specimens of Paradonea variegata and twenty more specimens of Gandanameno. As reported previously, Eresidae is divided into two major clades: one consisting of Seothyra, Dresserus, and Gandanameno, the other containing the remaining genera including Paradonea (Figs 51, S1). In our topology, Paradonea sits on a long branch sister to a clade consisting of Eresus, Adonea, Loureedia gen. n., and Dorceus; Stegodyphus is sister to this five-genus clade. Note that our exemplar for Paradonea is not the type species and the monophyly of this genus is uncertain. Our focus on sequencing Gandanameno was designed to elucidate species limits within the genus, in combination with morphological data (Figs 50, S2, S3). These results are discussed further in the section on Gandanameno, below.

(note: females of Paradonea striatipes Lawrence, 1968, Paradonea splendens (Lawrence, 1936), Paradonea parva (Tucker, 1920), and Paradonea presleyi sp. n. are unknown)

Adonea contains one recognized species, Adonea fimbriata Simon, 1873, from the Mediterranean. In addition, Eresus algericus El-Hennawy, 2004 is transferred to Adonea and may be a junior synonym of Adonea fimbriata. We examined syntype specimens from Algeria and Tunisia, and additional specimens from the Algeria-Morocco border and Israel.

Male distinguished from other eresids except Paradonea splendens by the profile of the carapace, which has the posterior part of the cephalic region overhanging the anterior part of the thoracic region (Fig. 19D); distinguished from Paradonea splendens by several characters including the subtriangular shape of the cephalic region that is rounded posteriorly (Fig. 19A; trapezoidal in Paradonea splendens and straight posteriorly, Fig. 68D) and by the mesally contiguous chelicerae (Fig. 19C; mesally excavated in Paradonea splendens, Fig. 68F).

Female distinguished from other eresids except Loureedia gen. n., Eresus walckenaeri Brullé, 1832, and some Paradonea species by the relatively large PME (AME/PME ca. 0.4, Fig. 19G); distinguished from Loureedia gen. n. by the longer than wide cephalic region (wider than long in Loureedia gen. n.); from Eresus walckenaeri by the presence of a glabrous median lobe between the copulatory openings (Fig. 22A; hirsute cuticle between the copulatory openings in Eresus walckenaeri, Fig. 42B); and from Paradonea variegata by the nearly vertical posterior margin of the cephalic region (Figs 1A, 19H; cephalic region only moderately raised in Paradonea variegata); females of other Paradonea species are unknown. The proportions of the epigynum in Adonea, which is more than two times wider than long, further separates it from most eresids (Figs 16A, 22A).

Known from Loess desert habitat with low shrubs, often in wadis. They build a simple vertical or inclined burrow lined by silk, often on the edge of stones. The opening is covered by a silken flap camouflaged from above by debris. Signaling threads radiate out from the edges of this roof. Prey include various epigaeic arthropods, especially beetles from the family Tenebrionidae. Prey remnants are incorporated into the roof of the burrow. Males take approximately 2–3 years to mature, females one year longer (Martin Forman, personal observation).

Male (Algeria-Morocco, MR012, MR): Carapace with band of white setae around margin of thoracic region and scattered patches elsewhere; cephalic region subtriangular, longer than wide, strongly raised with rounded posterior margin overhanging thoracic region; AME distinctly smaller than PME (AME/PME 0.48), median eyes slightly overlapping on horizontal and vertical axes, PME somewhat sunken into carapace; ALE tubercles present; PER slightly narrower than AER (PER/AER 0.88), PLE position on carapace 0.35; clypeal hood forms acute angle; fovea indistinct. Chelicerae contiguous mesally, with lateral boss. Legs with bands of white setae; with row of distal ventral macrosetae on metatarsus I–IV and scattered short ventral macrosetae on tibia, metatarsus and tarsus I–IV. Abdomen dark gray, nearly encircled by a band of white setae, with numerous patches of white setae dorsally, especially around sigilla (Figs 8A, B, 19A–D).

Male palp with proximal-distal axis, tegulum moderately elongate, subtrapezoidal; second loop of sperm duct curves proximally away from then back to distal margin of tegulum in retrolateral view (Figs 12B, 19J); conductor and embolus together form apical complex making one helical turn; conductor tapers to point; tegular division longer than embolic division; cymbium with one retrolateral and several prolateral macrosetae (Figs 12A–C, 19I, J, 20A–F).

Female (Wadi Mashash, Israel, MR013, HUJ): Carapace with scattered white setae; cephalic region subtriangular, longer than wide, so strongly raised as to be nearly vertical (Figs 1A, 19H); AME distinctly smaller than PME (AME/PME 0.37), median eyes slightly overlapping on horizontal and vertical axes; PME somewhat sunken into carapace; ALE tubercles indistinct; PER slightly narrower than AER (PER/AER 0.82), PLE position on carapace 0.39; clypeal hood forms acute angle; fovea indistinct (Figs 8C, D, 19E-H, 21A, B, E). Chelicerae contiguous mesally, boss present (Figs 19G, 21C, D). Legs with row of distal ventral macrosetae on metatarsus I–IV and scattered short ventral macrosetae on tibia, metatarsus and tarsus I–IV. Abdomen with numerous patches of white setae dorsally, especially around sigilla (Figs 1A, 19E).

Epigynum with slightly converging slit-like atria occupying nearly the total length, anterior-lateral margin a curved ridge (Figs 16A, 22A). Vulva with spermathecal heads set anterior-mesally on curved stalks leading to multilobed spermathecae that diverge posteriorly (Figs 16D, 22B–D).

Figure 19.

A–J Adonea fimbriata. A–D, I–J male from Algeria-Morocco (MR012, MR) E–H female from Mehav Am village, Israel (MR003, MR) A–D habitus of male, photomicrographs E–H habitus of female photomicrographs I, J illustrations of left male palp A, E dorsal view B, F ventral view C, G anterior view. D, H lateral view I prolateral view J retrolateral view. C conductor E embolus ST subtegulum T tegulum.

Figure 20.

A–F Adonea fimbriata from Algeria-Morocco (MR012, MR), scanning electron micrographs of right male palp, images reversed to appear as left palp. A prolateral view B retrolateral view C detail of embolic division, prolateral view D detail of embolic division, retrolateral view E ventral view F apical view. C conductor E embolus ST subtegulum T tegulum.

Figure 21.

A–F Adonea fimbriata from Mehav Am village, Israel (MR003, MR), scanning electron micrographs of female prosoma. A anterior view B dorsal view C left chelicerae, lateral view D left cheliceral boss E lateral view F sternum and coxae, ventral view

Figure 22.

A–F Adonea fimbriata, scanning electron micrographs. A female from Mehav Am village, Israel (MR003, MR) B–D female from Wadi Mashash, Israel (MR013, HUJ) E, F male from Algeria-Morocco (MR012, MR) A–D vulva E, F epiandrous region A epigynum, ventral view B cleared vulva, dorsal view C detail, spermathecal heads D detail, right spermatheca E epiandrous region F detail of epiandrous gland spigots. ML median lobe S spermatheca SH spermathecal head.

Figure 23.

A–F Adonea fimbriata, female from Mehav Am village, Israel (MR003, MR), scanning electron micrographs of spinnerets. A right ALS B detail of spigots on right ALS C PMS D right PLS E cribellar spigots F arrow indicating tarsal organ, left leg I. Unlabeled spigots in C thought to be a mixture of aciniform gland spigots and cylindrical gland spigots. AC aciniform gland spigot MAP major ampullate gland spigot mAP minor ampullate gland spigot PI piriform gland spigot.

Figure 24.

A–F Adonea fimbriata, male from Algeria-Morocco (MR012, MR), scanning electron micrographs of spinnerets. A overview B right ALS C right PMS D right PLS E aciniform field on right PLS F modified spigot on right PLS. AC aciniform gland spigot ALS anterior lateral spinneret MAP major ampullate gland spigot mAP minor ampullate gland spigot MS modified spigot PI piriform gland spigot PLS posterior lateral spinneret PMS posterior median spinneret.

Figure 25.

A–F Adonea fimbriata, scanning electron micrographs. A–C male from Algeria-Morocco (MR012, MR) D–F female from Mehav Am village, Israel (MR003, MR) A–C spinnerets and vestigial cribellum. D–F legs of female A detail of spigots on right male ALS B vestigial cribellum C detail of vestigial cribellum D trichobothrium, left metatarsus I E calamistrum, right metatarsus IV F detail, calamistrum seta, right metatarsus IV. MAP major ampullate gland spigot.

(Mehav Am village, Israel, MR003, MR, and Algeria-Morocco, MR012, MR). Female ALS with at least 5 MAP, at least 1 within and at least 4 on mesal edge of spinning field, with at least 40 PI (Fig. 23A, B); male with fewer PI (Fig. 24B). Female PMS with 2 anterior mAP, posterior field of 21 spigots that vary in size and shape (Fig. 23C); male with only 7 posterior spigots, suggesting that female may have both AC and CY spigots (Fig. 24C). Male PLS with basal MS apparently unaccompanied by flanking AC, distal field of 15 AC (Fig. 24D, F; our female preparation inadequate to view spigots). Male cribellar plate with no sign of spigots (Fig. 25B, C); epiandrous gland spigots present (Fig. 22E, F).

Dorceus contains five recognized species previously recorded only from North Africa. The genus was revised by El-Hennawy (2002). We examined specimens of Dorceus fastuosus C. L. Koch, 1846 from Israel and Senegal and the Tunisian holotype of Dorceus viberti Simon, 1910, which is a junior synonym of this species. The holotype of Dorceus fastuosus is a dry pinned specimen and was not examined. But we examined material that El-Hennawy examined for his 2002 revision (9126, AR5404, NMHN and 1237, AR 5405, NMNH) and compared to the holotype.

Distinguished from other eresid genera except Seothyra by the small median eyes subequal in size (Fig. 26C, G; AME/PME > 0.7), and the long, extensible ALS contrasting with reduced PLS (Fig. 32A; although ALS may be retracted and therefore not look so long); distinguished from other eresid genera except Loureedia gen. n., some Dresserus, and Paradonea splendens by the cephalic region, which is wider than long. Male distinguished from Seothyra by the subequal legs I and II (Fig. 26A; leg I enlarged in Seothyra, Figs 72A, 74A) and by the form of the conductor, which is a simple spiral or L-shaped hook shorter than the tegulum (Fig. 27A–C, El-Hennawy 2002; highly variable and elaborate in Seothyra, usually longer than the tegulum; see Dippenaar-Schoeman 1990); distinguished from Loureedia gen. n. by the unbranched conductor (Fig. 27A–C; bifid in Loureedia gen. n., Fig. 63D, E); distinguished from Dresserus by the lack of prominent tubercles bearing the ALE and the palpal conformation, which has a proximal-ventral axis with the helical embolus encircling the distal part (Figs 26I, J, 27A–E; obliquely ventral-dorsal in Dresserus with the embolus encircling the ventral part, Figs 33I–K, 34A–D); from Paradonea splendens by the subrectangular shape of the cephalic region, which does not overhang the thoracic region posteriorly and the mesally contiguous chelicerae (Figs 8F, 26A, C; subtrapezoidal, slightly overhanging the thoracic region, chelicerae mesally excavated in Paradonea splendens, Fig. 68D, F). Female distinguished from Seothyra by the median lobe of the epigynum, which is as wide as long or wider with more or less straight, converging lateral margins (Figs 16B, 29C; clearly longer than wide with a central constriction in Seothyra; see Dippenaar-Schoeman 1990); from Loureedia gen. n. by the small eyes subequal in size (Fig. 26C, G) and details of the female genitalia.

Dorceus was revised by El-Hennawy in 2002. However, the quantity and quality of specimens available to him for several species was limited.

Past morphological studies have placed Dorceus and Seothyra as close relatives (Fig. 8A; Lehtinen 1967). A recent molecular study contradicted this hypothesis (Fig. 7B; Miller et al. 2010a). Although some of us were involved in that molecular study, we do not consider the question resolved. Morphological similarities, including features of the eyes and spinnerets, remain compelling. On the other hand, Peters (1992a) pointed out morphological characteristics shared (through parallel evolution) by Seothyra and the distantly related sparasid Leucorchestris arenicola exclusive of the eresid Stegodyphus, particularly the large ALS, which are extensible and retractable. This morphology is apparently linked to burrowing in loose sand, which Dorceus does as well. Whether these attributes ultimately prove to be the result of shared ancestry or convergence in Eresidae remains fertile ground for future study.

Known from sand dunes in deserts with very sparse shrub, grass, and annual herb patches. Juveniles feed on their mother’s corpse before dispersing (El-Hennawy 1998; cf. Fig. 3D). Males take approximately 3 years to mature, females one year longer (Martin Forman, personal observation).

Male (Mashabin Sand Dunes, Israel, MR006, HUJ): Carapace with few white setae; cephalic region subrectangular, wider than long, strongly raised, with silvery patches around some eyes; AME slightly smaller than PME (AME/PME 0.95), median eyes adjacent on horizontal axis, slightly overlapping on vertical axis; ALE tubercles absent; PER as wide as AER (PER/AER 0.99), PLE position on carapace 0.45; clypeal hood forms a nearly 90° angle; fovea moderately deep (Figs 8E, F, 26A–D, 28A). Chelicerae slightly excavated mesally, with lateral boss (Figs 26C, 28B). Legs with bands of white setae; with row of distal ventral macrosetae on metatarsus I–IV, one subdistal ventral macroseta on tibia IV, and scattered ventral macrosetae on metatarsus and tarsus I–IV, strongest and most numerous on metatarsus and tarsus IV. Abdomen gray, white dorsally with large dark heart mark (Fig. 26A).

Male palp with proximal-distal axis; tegulum bulbous; conductor and embolus together form apical complex making one helical turn (Fig. 27C, E); conductor tapers to point; tegular division longer than embolic division; cymbium with several prolateral macrosetae (Figs 12D–F, 26I, J, 27A–E).

Female (Mashabim Reserve, Israel, MR): Carapace with scattered white setae; cephalic region subrectangular, wider than long, strongly raised (Fig. 26H); AME slightly smaller than PME (AME/PME 0.83), median eyes slightly overlapping on horizontal axis, separated on vertical axis; ALE tubercles absent; PER as wide as AER (PER/AER 0.97), PLE position on carapace 0.47; clypeal hood forms a nearly 90° angle; fovea moderately deep (Figs 8G, H, 26E–H, 29A, B). Chelicerae contiguous mesally, with lateral boss (Fig. 26G). Legs with row of distal ventral macrosetae on metatarsus III–IV and numerous macrosetae on metatarsus and tarsus III–IV. Abdomen without conspicuous white setae (Fig. 26E, H).

Epigynum with curved, converging slit-like atria occupying ca. the posterior half, anterior-lateral margin a curved ridge with median septum leading to subtrapezoidal median lobe (Figs 16B, 29C). Vulva with spermathecal heads set anterior-mesally on sinuous stalks leading to multilobed spermathecae that diverge posteriorly (Figs 16E, 29D–F).

Figure 26.

A–J Dorceus fastuosus. A–D, I–J male from Mashabin Sand Dunes, Israel (MR006, HUJ) E–H female from Mashabim sand dunes, Israel (MR002, MR) A–D habitus of male, photomicrographs E–H habitus of female, photomicrographs J, K illustrations of left male palp. A, E dorsal view B, F ventral view C, G anterior view D, H lateral view. I prolateral view. J retrolateral view. C conductor E embolus ST subtegulum T tegulum.

Figure 27.

A–F Dorceus fastuosus from Mashabin Sand Dunes, Israel (MR006, HUJ), scanning electron micrographs of left male palp. A prolateral view B retrolateral view C detail of embolic division, prolateral view D ventral view E detail of embolic division, ventral view F palpal tibia, dorsal view. C conductor E embolus ST subtegulum T tegulum.

Figure 28.

A–D Dorceus fastuosus, male from Mashabin sand dunes, Israel (MR006, HUJ), scanning electron micrographs. A prosoma, anterior view B left chelicerae, lateral view C chelicerae, anterior distal view showing fangs and teeth D epiandrous region.

Figure 29.

A–F Dorceus fastuosus, female from Mashabim sand dunes, Israel (MR002, MR), scanning electron micrographs. A median eye group B prosoma, dorsal C epigynum, ventral view D cleared vulva, dorsal view E detail, left spermathecal head F detail, right spermatheca. ML median lobe S spermatheca SH spermathecal head.

Figure 30.

A–F Dorceus fastuosus, female from Mashabim sand dunes, Israel (MR002, MR), scanning electron micrographs of spinnerets. A left ALS B left PMS C detail of left PMS D left PLS E aciniform field on left PLS F modified spigot and flanking aciniform gland spigot on left PLS. Unlabeled spigots in B and C thought to be a mixture of aciniform gland spigots and cylindrical gland spigots. AC aciniform gland spigot MAP major ampullate gland spigot mAP minor ampullate gland spigot MS modified spigot PI piriform gland spigot.

Figure 31.

A–F Dorceus fastuosus, female from Mashabim sand dunes, Israel (MR002, MR), scanning electron micrographs. A detail of spigots on left ALS B cribellum C detail cribellar spigots D trichobothrium, left tibia IV E calamistrum, left metatarsus IV F detail, calamistrum seta, left metatarsus IV. MAP major ampullate gland spigot PI piriform gland spigot. 

Figure 32.

A–F Dorceus fastuosus, male from Mashabin Sand Dunes, Israel (MR006, HUJ), scanning electron micrographs of spinnerets. A overview B left ALS C left PMS D left PLS E vestigial cribellum F modified spigot and flanking aciniform spigot on left PLS. AC aciniform gland spigot ALS anterior lateral spinneret MAP major ampullate gland spigot mAP minor ampullate gland spigot MS modified spigot PI piriform gland spigot PLS posterior lateral spinneret PMS posterior median spinneret.

(Mashabim sand dunes, Israel, MR002, MR and MR006, HUJ). Female ALS with at least 3 MAP near inner edge of spinning field of more the 50 PI (Figs 30A, 31A); male with about 25 PI spigots, 1 possible MAP visible (Fig. 32B). Female PMS with 1 anterior mAP and 20 spigots of various sizes posterior to this (Fig. 30B, C); male with 1 mAP and only 7 AC spigots (Fig. 32C), suggesting that female may have AC and CY spigots. Female PLS with anterior-basal MS and 1 accompanying AC, distal field of about 40 AC (Fig. 30D–F); male same except with only 12 AC (Fig. 32D). Male cribellar plate with no sign of spigots (Fig. 32E); epiandrous gland spigots present (Fig. 28D).

Dresserus contains 24 recognized species from eastern and southern Africa (Platnick 2011). We examined specimens of multiple unidentified Dresserus species. Observations of the male plus the female spinneret spigot morphology is based on specimens from Mazumbai, West Usambara Mts., Tanzania (CASENT 9025746, CAS and CASENT 9025747, CAS); other observations of the female based on specimens from Klein Kariba (CASENT 9025745, CAS) and Drummond (CASENT 9037024, CAS), South Africa; other observations of the male based on specimens from Manga Forest Reserve, Tanzania (Frontier Tanzania, ZMUC), Hluhluwe Game Reserve, South Africa (TM 19739, TMSA), and Witbank, South Africa (TM 19738, TMSA).

Distinguished from other eresids except Gandanameno by the position of the PLE which are both advanced (< 0.28) and widely spaced (PER/AER > 0.95; Fig. 8J); other eresids with advanced PLE (e.g., Stegodyphus, some Paradonea) have them closer together (PER/AER < 0.90) than the ALE (Figs 10B, 11B, D, F, H, J, L). Generally distinguished from other eresids by the distinctive 4-part cribellum (Fig. 36F), although some Gandanameno specimens show signs of this characteristic. Males distinguished from other eresids by the prominent tubercles bearing the ALE (Figs 8J, 33A), which are much more pronounced from those in other genera with ALE tubercles (e.g., Stegodyphus, some Paradonea). Further distinguished from other eresids except Gandanameno by the more or less ventral-dorsal axis of the palpal bulb with the embolus encircling the ventral part (Figs 12G–I, 33I–K, 34A–D; proximal-ventral in other eresids with the embolus encircling the distal part); distinguished from Gandanameno by the smooth conductor (Fig. 34C, D; fringed in Gandanameno, Fig. 55C, E). The cephalic region may be wider than long (e.g., TM 19738, TMSA, Frontier Tanzania, ZMUC) or longer than wide (e.g., TM 19739, TMSA). Female further distinguished from other eresids except Gandanameno and Eresus walckenaeri by the copulatory openings, which are broadly separated by hirsute cuticle (Figs 16C, 37D; separated by a glabrous median lobe in other eresids, e.g., Figs 16B, 29C); Gandanameno and Dresserus together distinguished from other eresids including Eresus walckenaeri by the vulva, which have the spermatheca extending anterior of the spermathecal heads, together subtended by helical copulatory ducts (Figs 16F, 37E; other eresids have the spermathecal head anterior, spermatheca posterior, and copulatory ducts other than helical), and by the subdivided PMS (entire in other eresids) with numerous short, conical, cylindrical(?) gland spigots (Fig. 36C, D; this spigot morphology absent in other eresids); distinguished from Gandanameno by the somewhat less prominent paired atria and possibly by having a single loop of the copulatory duct (Fig. 37E; three in Gandanameno, although this character has been investigated in few Dresserus species).

Thetaxonomic literature on Dresserus is fragmentary and rarely comparative. This genus is ripe for revision. We have been unable to confidently assign species names to the specimens used in this study. Lehtinen (1967: 231) indicated that he was working on a taxonomic revision, but none was ever published. According to him, all but one of the described species (including the type species) had been checked and verified as congeneric based on primary types and other material.

Known from Savanna, stony semidesert, and forest habitats. They build a silken tube under stones. Prey is mainly beetles (Milan Řezáč, personal observation). Clutches consist of tens of juveniles (Martin Forman, personal observation of Dresserus kannemeyeri). Juveniles do not feed on their mother’s corpse. Mature females can live for several years in captivity and can produce a number of sequential clutches (Martin Forman, personal observation of Dresserus kannemeyeri).

Male (Manga Forest Reserve, Tanzania, ZMUC): Carapace with few white setae, mostly in thoracic region; cephalic region subrectangular, wider than long, moderately raised; AME distinctly smaller than PME (AME/PME 0.71), median eyes overlapping on horizontal axis, separated on vertical axis; ALE placed on pointed apophyses, PER slightly wider than AER (PER/AER 1.04), PLE position on carapace 0.27, clypeal hood forms obtuse angle, fovea deep. Chelicerae slightly excavated mesally, with lateral boss. Legs with white setae, with row of distal ventral macrosetae on metatarsus II–IV. Abdomen dark gray, nearly encircled by a band of white setae (Figs 8I, J, 33A–D).

Male palp with dorsal-ventral axis; tegulum disc-shaped; conductor arises on broad membranous stalk from center of tegulum, with arching distal and proximal arms covering much of mesal portion of palpal bulb, distal arm larger than proximal, fringe absent (Fig. 34D); embolus makes slightly more than one loop, long and flexible, fits into groove originating on prolateral arm of conductor; cymbium without distinct macrosetae (Figs 12G–I, 33I–K, 34A–D).

Female (Mazumbai, Tanzania, CASENT 9025747, CAS): Carapace without conspicuous white setae; cephalic region subrectangular, about as wide as long, moderately raised; AME distinctly smaller than PME (AME/PME 0.41), median eyes overlapping on horizontal axis, separated on vertical axis; ALE tubercles absent; PER as wide as AER (PER/AER 1.04), PLE position on carapace 0.27; clypeal hood forms obtuse angle, fovea deep. Chelicerae contiguous mesally, with lateral boss (Fig. 35E, F). Legs with white setae, with row of distal ventral macrosetae on metatarsus II–IV. Abdomen without conspicuous white setae (Figs 8K, L, 33E–H).

Epigynum with pair of longer-than-wide atria on posterior margin separated by hirsute cuticle (Figs 16C, 37D). Vulva with copulatory ducts making one loop leading to anterior complex of spermatheca and spermathecal head. Fertilization duct runs posteriorly through the copulatory duct loop (Figs 16F, 37E).

Figure 33.

A–K Dresserus sp. A–D male from Manga Forest Reserve, Tanzania (ZMUC), image D reversed E–H female from Mazumbai, Tanzania (CASENT 9025747, CAS) I–K male from Mazumbai, Tanzania (CASENT 9025746, CAS) A–D habitus of male, photomicrographs E–H habitus of female, photomicrographs I–K illustrations of left male palp A, E dorsal view B, F ventral view C, G anterior view D, H lateral view I prolateral view J ventral view K retrolateral view. C conductor E embolus ST subtegulum T tegulum.

Figure 34.

A–F Dresserus sp. A–E male from Mazumbai, Tanzania (CASENT 9025746, CAS), scanning electron micrographs of right palp, images reversed to appear as left palp F female from Klein Kariba, South Africa (CASENT 9025745, CAS), scanning electron micrographs of left chelicera A prolateral view B retrolateral view C ventral view D apical view E palpal tibia, dorsal view F distal part of chelicerae showing fang and teeth. C conductor E embolus T tegulum.

Figure 35.

A–F Dresserus sp., female from Klein Kariba, South Africa (CASENT 9025745, CAS), scanning electron micrographs of prosoma. A anterior view, chelicerae removed, arrow indicates clypeal hood B dorsal view of eye region C fovea D sternum E right chelicera, ectal view F right cheliceral boss.

Figure 36.

A–F Dresserus sp., female from Mazumbai, Tanzania (CASENT 9025747, CAS), scanning electron micrographs of spinnerets. A overview B left ALS C right PMS D detail, cylindrical gland spigots on right PMS E left PLS F cribellum. AC aciniform gland spigot ALS anterior lateral spinneret CR cribellum CY cylindrical gland spigot MAP major ampullate gland spigot mAP minor ampullate gland spigot MS modified spigot PI piriform gland spigot PLS posterior lateral spinneret PMS posterior median spinneret.

Figure 37.

A–F Dresserus sp., scanning electron micrographs. A, C female from Mazumbai, Tanzania (CASENT 9025747, CAS) D, F female from Klein Kariba, South Africa (CASENT 9025745, CAS) A detail of spigots on right ALS B detail of spigots on anterior part of PMS C detail of spigots on anterior part of right PMS D epigynum, ventral view E vulva, dorsal view F detail of pores on right spermathecal head. AC aciniform gland spigot CD copulatory duct CY cylindrical gland spigot FD fertilization duct MAP major ampullate gland spigot mAP minor ampullate gland spigot PI piriform gland spigot S spermatheca SH spermathecal head t tartipore.

Figure 38.

A–F Dresserus sp., female from Klein Kariba, South Africa (CASENT 9025745, CAS), scanning electron micrographs of legs A tarsal organ, left leg I B trichobothrium, left leg I C tarsal claw, left leg I setae removed D left metatarsus IV, retrolateral view, showing calamistrum E detail of calimistrum F detail of teeth on calimistrum setae.

Figure 39.

A–F Dresserus sp., male from Mazumbai, Tanzania (CASENT 9025747, CAS), scanning electron micrographs of spinnerets and epiandrous region. A overview of spinnerets B right ALS C PMS D left PLS E modified spigot on right PLS F epiandrous region. AC aciniform gland spigot ALS anterior lateral spinneret MAP major ampullate gland spigot mAP minor ampullate gland spigot MS modified spigot n nubbin PI piriform gland spigot PLS posterior lateral spinneret PMS posterior median spinneret t tartipore.

(Mazumbai, Tanzania, CASENT 9025746, CAS and CASENT 9025747, CAS). Female ALS with at least 4 MAP within and 4–6 along inner edge of spinning field of more than 40 PI (Figs 36B, 37A); male with 4 MAP within and 3–5 along inner edge of spinning field of about 35 PI spigots (Fig. 39B). Female PMS longitudinally elongate, transversely bilobed, with 2 anterior mAP, between these 2–3 AC, posterior to this on anterior and posterior lobes a dense field of more than 105 short, squat, conical CY spigots (Figs 36C, D, 37B, C); male PMS small, oval, with 2 anterior mAP and 3 AC (Fig. 39C). Female PLS with anterobasal MS without accompanying spigot and distal field of 9 AC (Fig. 36E); male same (Fig. 39D, E). Male cribellar plate with no sign of spigots; epiandrous gland spigots present (Fig. 39F).

Eresus contains 23 recognized species group names (including 6 subspecies) from the Mediterranean and temperate latitudes of Europe and Asia. We examined specimens of several species representing the two major morphological groups within the genus. Our first exemplar, Eresus walckenaeri, is a cohesive species, based on both morphological and molecular data (Johannesen et al. 2005). Our specimens were from Bulgaria and Greece (Kresna, Bulgaria, MR; Pieria, Greece, MR020, MR; Lakonia, Greece, ZMUC 00012903, ZMUC). The primary types of Eresus walckenaeri are probably lost, but the original description and drawings, and our use in part of nearly topotypic material, allow us to identify this species with confidence. The second major group within the genus is a complex of closely related species including Eresus kollari (including the junior synonyms Eresus cinnaberinus and Eresus niger) and Eresus sandaliatus (Martini & Goeze, 1778); we refer to this assemblage collectively as the Eresus sandaliatus group. The somatic description was based on specimens of Eresus kollari from Czechia (Srbsko, MR016, MR; Prague, MR007, MR); scanning electron micrographs of the male palp are from a specimen of Eresus kollari from Hungary (Remete Mountain, CASENT 9037134, CAS); scanning electron micrographs and some photographs of the female genitalia are from a specimen of Eresus sandaliatus from SE of Silkeborg, Denmark (CASENT 9039243, CAS). The spinneret spigot morphology of Eresus sandaliatus group species was described and scanned in Griswold et al. (2005: 24–27, figs 31–32, 33A–F, 34A–C). Řezáč et al. (2008) examined copious material from the Eresus sandaliatus group including one of the two syntypes of Eresus kollari.

We found no characters that clearly and simultaneously separate Eresus females from other eresid genera, despite support from molecular data for a monophyletic Eresus (Miller et al. 2010a). Separate diagnoses for females of the two species groups appear in the following section.

Male Eresus are usually recognized by their distinctive dorsal abdominal pattern, which features two pairs of large round dark patches surrounding the first and second sigilla on a field of red setae, sometimes with a pair of smaller dark patches surrounding the third sigilla (Figs 2B, D, 40A, 43A); if with a black abdomen, then recognized by the distinctive notch on the embolic conductor (cf. Fig. 43J; note that black-abdomened form known as Eresus tristis Kroneberg, 1875 is currently cataloged as a synonym of Eresus kollari, but this is not accepted by all workers, e.g., Řezáč et al. 2008: 264, who noted that it is an “obviously different species”). Females of Eresus walckenaeri distinguished from other eresids except Dresserus and Gandanameno by the copulatory openings, which are broadly separated by hirsute cuticle (Figs 16G, 42B; separated by a glabrous median lobe in other eresids, e.g., Figs 16B, I, 29C, 45A), distinguished from Dresserus and Gandanameno by the more posterior position of the PLE (<0.28 in Gandanameno and Dresserus, > 0.33 in Eresus walckenaeri); females of the Eresus sandaliatus group distinguished from other eresids except Paradonea variegata by the large, bulbous spermathecal head (Figs 16K, L, 45B–D), distinguished from Paradonea variegata by the smaller size difference between the AME and PME (AME/PME > 0.5 in Eresus sandaliatus group, Fig. 9C; < 0.4 in Paradonea variegata, Fig. 10G) and by the overall darker color; thick stalks leading to the spermathecal head in some Stegodyphus species can be mistaken for large, bulbous spermathecal heads (Fig. 18J) although they are in fact compact sinuous ducts (Fig. 82B); Eresus sandaliatus group further distinguished from Stegodyphus by the more posterior position of the PLE (> 0.33 in Eresus sandaliatus group; < 0.29 in Stegodyphus).

Male of Eresus walckenaeri distinguished from those of the Eresus sandaliatus group by the ribbon-like conductor with a blunt, rounded tip (Fig. 41C, D; notched in Eresus sandaliatus group, Fig. 44D, E) and the 1.5 helical turns of the embolus (ca. 1 helical turn in Eresus sandaliatus group). Various species within the Eresus sandaliatus group distinguished primarily by coloration and details of the conductor shape and vulva (Fig. 16H, I, K, L; see also Řezáč et al. 2008).

Known from various non-forest warm and dry habitats. Some species build a simple vertical burrow lined with silk. The opening is covered by silken sheet camouflaged from above by debris. Signaling threads radiate out from the edges of this roof. Some species (e.g., Eresus walckenaeri, Eresus crassitibialis Wunderlich) do not dig burrows; their silken tubes lie just under stones or on (Milan Řezáč, personal observation).

Male (Prague, Czechia, MR007, MR): Carapace with scattered white setae; cephalic region subtriangular, longer than wide, moderately raised; AME distinctly smaller than PME (AME/PME 0.63), median eyes adjacent on horizontal axis, slightly overlapping on vertical axis; ALE tubercles absent; PER slightly narrower than AER (PER/AER 0.89), PLE position on carapace 0.33; clypeal hood forms acute angle; fovea shallow. Chelicerae contiguous mesally, with lateral boss. Legs with clusters of white setae; with single distal ventral macroseta on metatarsus I, row of distal ventral macrosetae on metatarsus II–IV, scattered ventral macrosetae on metatarsus and tarsus II–IV, strongest and most numerous on metatarsus and tarsus IV, and retrolateral macroseta on metatarsus IV. Abdomen red dorsally with large dark patches surrounding anterior two pairs of sigilla (Figs 2D, 40A–D).

Male palp with proximal-distal axis; tegulum subtrapezoidal; conductor and embolus together form apical complex making 1.5 helical turns; conductor ribbon-like with blunt, rounded tip; tegular division longer than embolic division (Figs 12J–L, 40I, J, 41A–D, F); cymbium with several prolateral macrosetae (Fig. 41E).

Female (Srbsko, Czechia, MR016, MR): Carapace with few scattered white setae; cephalic region subtriangular, longer than wide, moderately raised; AME distinctly smaller than PME (AME/PME 0.63), median eyes separated on horizontal axis, adjacent on vertical axis; ALE tubercles absent; PER slightly narrower than AER (PER/AER 0.87), PLE position on carapace 0.34; clypeal hood forms acute angle; fovea shallow. Chelicerae contiguous mesally, with lateral boss. Legs without conspicuous white setae; legs with row of distal ventral macrosetae on metatarsus I–IV plus additional ventral macrosetae on metatarsus and tarsus I–IV. Abdomen without conspicuous white setae (Fig. 40E–H; see Fig. 2C for color of live animal).

Epigynum with pair of wide atria on posterior margin separated by hirsute cuticle (Figs 16G, 42B). Vulva with spermathecal heads on long sinuous stalks gradually transitioning to sinuous multilobed spermathecae (Figs 16J, 42D–F).

Figure 40.

A–J Eresus walckenaeri. A–D, I–J male from Kresna, Bulgaria (MR) E–H female from 5 km south of Monemvasia, Lakonia, Greece (ZMUC 00012903, ZMUC) A–D habitus of male, photomicrographs E–H habitus of female, photomicrographs I, J illustrations of left male palp A, E dorsal view B, F ventral view C, G anterior view D, H lateral view I prolateral view J retrolateral view. C conductor E embolus ST subtegulum T tegulum.

Figure 41.

A–F Eresus walckenaeri from Kresna, Bulgaria (MR), scanning electron micrographs of right male palp, images reversed to appear as left palp. A prolateral view B retrolateral view C detail of embolic division, prolateral view D detail of embolic division, retrolateral view E apex of cymbium, ventral view F detail of embolic division, apical view. C conductor E embolus ST subtegulum T tegulum.

Figure 42.

A–F Eresus walckenaeri female from 5 km south of Monemvasia, Lakonia, Greece (ZMUC 00012903), scanning electron micrographs. A prosoma, anterior view B epigynum C tarsal organ, left leg I. ventral view D vulva, dorsal view E left spermatheca F left spermathecal head. S spermatheca SH spermathecal head.

Male (Prague, Czechia, MR007, MR): Carapace with scattered white setae; cephalic region subrectangular with broadly rounded posterior margin, longer than wide, moderately raised; AME distinctly smaller than PME (AME/PME 0.63), median eyes slightly separated on horizontal axis, slightly overlapping on vertical axis; ALE tubercles absent, PER slightly narrower than AER (PER/AER 0.89), PLE position on carapace 0.39; clypeal hood forms acute angle; fovea moderately deep. Chelicerae contiguous mesally, with lateral boss. Legs with bands of white setae; with row of distal ventral macrosetae on metatarsus I–IV plus additional ventral macrosetae on tibia, metatarsus and tarsus I–IV. Abdomen red dorsally with large dark patches surrounding anterior two pairs of sigilla (Figs 2B, 9A, B, 43A–D).

Male palp with proximal-distal axis; tegulum bulbous; conductor and embolus together form apical complex making one helical turn; conductor ribbon-like, tip broadly rounded with a notch (Figs 13A–C, 43I, J, 44A–F; Řezáč et al. 2008: fig. 5A, D); tegular division longer than embolic division; cymbium with several prolateral macrosetae.

Female (Srbsko, Czechia, MR016, MR): Carapace with scattered white setae; cephalic region subrectangular with broadly rounded posterior margin, longer than wide, moderately raised; AME distinctly smaller than PME (AME/PME 0.63), median eyes slightly overlapping on horizontal and vertical axes; ALE tubercles absent; PER slightly narrower than AER (PER/AER 0.89), PLE position on carapace 0.39; clypeal hood forms acute angle; fovea shallow. Chelicerae contiguous mesally, with lateral boss. Legs with scattered white setae, with row of distal ventral macrosetae on metatarsus I–IV plus additional ventral macrosetae on metatarsus and tarsus III–IV. Abdomen without conspicuous white setae (Figs 2A, 9C, D, 43E–H).

Epigynum with slit-like atria occupying nearly the total length, anteriomedian part with notch-shaped invagination, anteriolateral margin a curved ridge (Figs 16H, 45A; Řezáč et al. 2008: fig. 4G). Vulva with large, bulbous spermathecal heads anteriorly leading to posterior spermathecae with multiple weakly-differentiated lobes (Fig. 16K; cf. Figs 16L, 45B–D; Řezáč et al. 2008: fig. 4J).

Figure 43.

A–J Eresus kollari. A–D, I, J male from Prague, Czechia (MR007, MR) E–H female from res. Srbsko, Czechia (MR016, MR) A–D habitus of male, photomicrographs E–H habitus of female, photomicrographs I, J illustrations of left male palp A, E dorsal view B, F ventral view C, G anterior view D, H lateral view I prolateral view J retrolateral view, arrow indicates notch in conductor. C conductor E embolus T tegulum.

Figure 44.

A–F Eresus kollari from Remete Mountain, Hungary (CASENT 9037134, CAS), scanning electron micrographs of left male palp. A prolateral view B retrolateral view C ventral view D palpal bulb, retrolateral view E palpal bulb, retrodorsal view F apical view. C conductor E embolus ST subtegulum T tegulum.

Figure 45.

A–F Eresus spp., scanning electron micrographs. A–D Eresus sandaliatus female from SE of Silkeborg, Denmark (CASENT 9039243, CAS) E Eresus kollari female from Srbsko, Czechia (MR016, MR) F Eresus kollari male from Prague, Czechia (MR007, MR) A epigynum, ventral view B vulva, dorsal view C left spermathecal head D detail, left spermatheca E trichobothria, left tibia I F epiandrous region. ML median lobe S spermatheca SH spermathecal head.

Figure 46.

A–F Eresus kollari from Srbsko, Czechia (MR016, MR), scanning electron micrographs of female. A prosoma, anterior view B left cheliceral boss C detail of carapace texture D tarsal organ, left leg I E calamistrum, left metatarsus IV F detail, calamistrum seta, left metatarsus IV.

Gandanameno contains five recognized species from eastern and southern Africa. We examined the collection holdings of several museums and most primary type specimens. The oldest available name, Eresus fumosus C. L. Koch, 1837, apparently lacks any type specimen (Lehtinen 1967: 235). We evaluated morphological variation and analyzed DNA sequences from 24 individuals based on previously published and new data. Descriptions are based on a female specimen from Tanzania (ZMUC 19970530, ZMUC) and a male from Zimbabwe (AcAT 2005/123, NCA) supplemented by collections mostly from South Africa.

Distinguished from other eresids except Dresserus by the position of the PLE which are both advanced (< 0.28) and widely spaced (PER/AER > 0.95; Fig. 9F, H); other eresids with advanced PLE (e.g., Stegodyphus, some Paradonea) have them closer together (PER/AER < 0.90) than the ALE (e.g., Figs 10B, 11F). Male further distinguished from other eresids except Dresserus by the more or less ventral-dorsal axis of the palpal bulb with the embolus encircling the ventral part (Figs 13D, E, 48A–C; proximal-ventral in other eresids with the embolus encircling the distal part, e.g., Fig. 20A–F) and conductor arising from the center of the tegulum with opposing projections covering much of the palpal bulb (Fig. 55C); distinguished from Dresserus by the lack of prominent tubercles bearing the ALE (Fig. 9F; compare with Fig. 8J) and the fringed conductor (Fig. 55C, E; smooth in Dresserus, Fig. 34D). Female further distinguished from other eresids except Dresserus and Eresus walckenaeri by the copulatory openings, which are broadly separated by hirsute cuticle (Figs 17A–C, 59A; separated by a glabrous median lobe in other eresids, e.g., Figs 16B, 29C); Gandanameno and Dresserus together distinguished from other eresids including Eresus walckenaeri by the vulva, which have the spermatheca extending anterior of the spermathecal heads, together subtended by helical copulatory ducts (Figs 17D–F, 59C; other eresids have the spermathecal head anterior, spermatheca posterior, and copulatory ducts other than helical, e.g., Fig. 29D), and by the subdivided PMS (Fig. 57C; entire in other eresids) with numerous short, conical, cylindrical gland spigots (Fig. 58E; cylindrical gland spigots absent or difficult to distinguish from aciniform gland spigots in other eresids); distinguished from Dresserus by the somewhat more prominent paired atria (Figs 17A–C, 59A; compare with Figs 16C, 37D) and possibly by having three loops of the copulatory duct (Figs 17D–F, 59C; fewer in Dresserus, although this character has been investigated in few Dresserus species, Figs 16F, 37E). Both sexes usually distinguished from Dresserus by the two part cribellum (Figs 57E, 60E, compare with Fig. 36F), although signs of the distinctive 4-part cribellum are sometimes apparent in Gandanameno.

Gandanameno are variable in several conspicuous characteristics. In the male, these include the presence or absence of a cheliceral boss (Fig. 56C–F), palp size, details of the conductor shape, and the curvature and position of the tegular sperm duct (Figs 48B, D–F, S2A–J). In the female, these include the height of the cephalic region, and the presence of cuspules of various weights on the carapace, sternum, and basal segments of legs I, II, and sometimes III (Figs 50, 52A–F, 53A–F, 54A–F), also details of the epigynum shape (Figs 17A–C, S2K, L, S3A–F, H–L). It has been noted previously that multiple forms may occur sympatrically and that intermediate combinations make species determination problematic (Tucker 1920). Indeed, in most regions where several specimens are known, a wide range of variation can be found (Fig. 50). We attempted to sequence DNA from several museum specimens. Unfortunately, most of our successes were from specimens at one end of the range of variation, i.e., specimens with a moderately to strongly raised cephalic region and abundant, heavy cuspules on the carapace, sternum, and anterior legs. The three contrasting female specimens (13-10: KwaZulu-Natal; 18-04: AcAT 2002/181; 14517) did not group together. Instead, relationships appear to be more strongly tied to geography than to morphology (Fig. 51). The genitalia of 23 out of 24 Gandanameno specimens included in the molecular phylogenetic analysis are photo-documented in the electronic supplementary materials (Figs S2A–L, S3A–L).

We looked for patterns of variation in adult female morphology. Adult female specimens are much more abundant in collections than males. We defined eight geographic regions based on two criteria: 1) concentration of specimens available to us and/or 2) type localities of Gandanameno species (Figs 49, 50). We assessed a series of characters: carapace length, carapace width, presence and strength of cuspules on the ventral surface of femur I and II, prosoma, and sternum for all specimens available from these regions. When cuspules are present on the prosoma, they always occur on the femurs, but the reverse is not always true. So the set of specimens with cuspules on the femurs is larger than and contains the set of specimens with cuspules on the prosoma. There appears to be a general trend towards greater spinulation and a higher carapace with increasing size (carapace length), but the spinulation data are fairly noisy (Fig. 50). No morphological pattern emerged to segregate specimens by region. Not all degrees of spinulation were observed in every geographic region.

Based on the combination of genetic, morphometric, and spinulation data, we see no evidence that the characters traditionally used to discriminate Gandanameno species are valid. We speculate that ontogenetic factors are responsible for the morphological variation in this genus (perhaps juvenile nutrition or post adult molting). However, we judge that the synonymy of all Gandanameno species is premature, particularly in light of the phylogeographic signal suggested by the molecular data and the limited availability of specimens from beyond the Republic of South Africa. We therefore identify our specimens simply as Gandanameno sp. We encourage additional investigations that might further elucidate the systematics of Gandanameno.

Associated with crevices in or under rocks or tree bark in savanna, parks, and gardens. They build a silken tube with a widened entrance; the tube of an adult female under bark can be up to 1 m long (Martin Forman, personal observation). Also found under tree bark well above the ground in dense aggregations (Nikolaj Scharff, Jeremy Miller, Iringa, Tanzania). Prey remnants are placed at the bottom of the tube. Clutches consist of tens of juveniles (Martin Forman, personal observation). Juveniles do not feed on their mother’s corpse and adult females can produce a number of sequential clutches. Males mature in less than one year, females take longer (Martin Forman, personal observation).

Male (Harare, Zimbabwe, AcAT 2005/123, NCA): Male carapace with scattered white setae, cephalic region subrectangular, about as long as wide, slightly raised; AME distinctly smaller than PME (AME/PME 0.63), median eyes slightly overlapping on horizontal and vertical axes; ALE tubercles absent, PER nearly as wide as AER (PER/AER 0.95), PLE position on carapace 0.23; clypeal hood forms obtuse angle; fovea deep. Chelicerae contiguous mesally, without lateral boss (Fig. 56B–D; note that all other males examined have a cheliceral boss, Fig. 56E, F). Legs without conspicuous white setae; with row of distal ventral macrosetae on metatarsus I–IV. Abdomen dark without conspicuous white setae (Figs 9E, F, 47A–D).

Male palp with dorsal-ventral axis; tegulum disc-shaped; conductor arises on stalk from center of tegulum, with arching prolateral and retrolateral arms covering much of anterior portion of palpal bulb, retrolateral arm with fringed posterior margin; embolus makes ca. three loops, long and flexible, fits into groove originating on prolateral arm of conductor; cymbium without distinct macrosetae (Figs 13D–F, 48A–F, 55A–E, S2A–J).

Female (Iringa, Tanzania, ZMUC 19970530, ZMUC): Female carapace without conspicuous white setae; cephalic region subrectangular, longer than wide, slightly raised, AME distinctly smaller than PME (AME/PME 0.58), median eyes slightly overlapping on horizontal axis, adjacent on vertical axis; ALE tubercles absent, PER as wide as AER (PER/AER 1.03), PLE position on carapace 0.20; clypeal hood forms obtuse angle; fovea deep. Chelicerae contiguous mesally, with lateral boss. Legs without conspicuous white setae; legs with row of distal ventral macrosetae on metatarsus III–IV. Abdomen without conspicuous white setae (Figs 4E, F, 9G, H, 47E–P).

Epigynum bell-shaped, with pair of semicircular atria on posterior margin separated by hirsute cuticle (Figs 17A–C, 59A, B, S2K, L, S3A–F, H–L). Vulva with copulatory ducts making three loops leading to anterior complex of spermatheca and spermathecal head. Fertilization duct runs posteriorly through the copulatory duct loops (Figs 17D–F, 59C–F, S3G).

(Iringa, Tanzania, ZMUC 19970530, ZMUC; Hanover, South Africa, SAM-ENW-B006896/9958, SAM and SAM 9465, SAM): Female ALS with at least 7–8 MAP within and along inner edge of spinning field of 50–80 PI (Fig. 57B); male with 1 MAP within and 3 along inner edge of spinning field of about 40 PI spigots (Figs 60B, 61A). Female PMS longitudinally elongate, transversely bilobed, with 2–3 anterior mAP, between these 2–3 AC, posterior to this on anterior and posterior lobes a dense field of more than 40 (SAM-ENW-B006896/9958) to 55 (ZMUC 19970530, ZMUC) short, squat, conical CY spigots (Figs 57C, 58E, F); male PMS small, oval, with 2 mAP and 4 AC (Figs 60C, 61D). Female PLS with anterobasal MS without accompanying spigot and distal field of 9–15 AC (Figs 57D, 58C); male same (Figs 60D, 61B, C). Male cribellar plate with no sign of spigots (Fig. 60E, F); epiandrous gland spigots present (Fig. 61E, F). Cribellar plate divided medially, although some hint of subdivision into four fields of spigots (as in Dresserus) is evident (Fig. 57E).

Figure 47.

A–P Gandanameno sp., habitus, photomicrographs. A–D male from Harare, Zimbabwe (AcAT 2005/123, NCA), images reversed E–H female from Hanover, South Africa (SAM-ENW-B006896/9958, SAM) I–L female from Iringa, Tanzania (ZMUC 19970530, ZMUC) M–P female from Eierfontein, South Africa (SAM-12823, SAM) A, E, I, M dorsal view B, F, J, N ventral view C, G, K, O anterior view D, H, L, P lateral view.

Figure 48.

A–F Gandanameno sp., illustrations of left male palp. A–C from Naauwpoort, North West Province, South Africa (SAM 1600, SAM) D from Van Riebeeck Park, Western Cape, South Africa (CASENT 9023763, CAS) E from Graaff-Reinet, Eastern Cape, South Africa (SAM 12571, SAM) F from Hanover, South Africa (SAM 9465, SAM) A obliquely retrolateral view B, D–F ventral view C obliquely prolateral view. All images at the same scale. C conductor E embolus ST subtegulum T tegulum.