Diploglena Purcell, 1904

Haddad, Charles R., 2015, A revision of the southern African two-eyed spider genus Diploglena (Araneae: Caponiidae), African Invertebrates 56 (2), pp. 343-343 : 345-351

Genus Diploglena Purcell, 1904

Diploglena Purcell, 1904: 169 ; Dippenaar-Schoeman & JocQuÉ 1997: 118, fig. 61b; JocQuÉ & Dippenaar-Schoeman 2006: 88, fig. 21d; Platnick & JÄger 2008: 7 .

Type species: Diploglena capensis Purcell, 1904 , by monotypy. Diagnosis: Diploglena can be distinguished from the only other Afrotropical genus, Caponia , by the reduction of the eyes from eight to a single pair ( Figs 1 , 7 ), which are presumably the anterior median pair ( JocQuÉ & Dippenaar-Schoeman 2006). Further, Diploglena can be separated from Caponia by the male palp with a short embolus and associated membranous conductor, which form a separate structure to the tegular apophysis ( Figs 46–62 , 64–66 ), while in Caponia these structures are found together distally on a stalk-like extension of the tegulum ( Purcell 1904: figs 28–35). Diploglena shares with the South American genus Tisentnops the distally widened endites ( Figs 2 , 8 ) and the presence of a single pair of eyes, but can be separated from it by the lack of a series of squared denticles on the anterior margin of the endites (Platnick 1994 b: fig. 26).

Description: Carapace oval, clearly narrowed, rounded anteriorly, somewhat flattened, slightly concave posteriorly ( Figs 1 , 5 ); surface with network of fine shallow subrectangular pits ( Fig. 6 ), with scattered short fine setae, particularly around periphery and medially; longer thickened setae in oval cluster medially on thoracic region, also on clypeus ( Fig. 1 ); eyes reduced to single pair (anterior medians), surrounded by black pigment, about five times their diameter from anterior margin of carapace ( Fig. 1 ); eyes separated by approximately one-quarter their diameter ( Fig. 7 ). Sternum and labium separated by very fine suture, almost appearing fused ( Figs 2 , 8 ); labium elongate pentagonal, distal end unsclerotised; endites narrow proximally, widened distally, without distinct serrula, anteromedian corners unsclerotised ( Figs 2 , 8 ); sternum oval, covered in short fine curved setae; precoxal triangles present, intercoxal sclerites present between all coxal pairs, also between endites and coxae I ( Fig. 2 ); pleural membranes with isolated, weakly sclerotised epimeric sclerites dorsally above coxal pairs. Chelicerae with stridulatory file on antero-retrolateral surface of paturon ( Figs 3 , 9, 10 ), with corresponding stridulatory pick on prolateral surface of palpal femur, at approximately one-fifth its length; stridulatory pick of males forming nearly eQuilateral triangle ( Fig. 11 ), in females with additional distal thorn-like projection ( Fig. 12 ); chelicerae with fangs long, slender, strongly curved; paturon with translucent lamina, extending narrowly along mesal margin, continuing as broad membranous lobe along distal margin of paturon ( Figs 4 , 13 ); teeth absent; anteromedian margins of paturon with long bristles converging medially ( Fig. 1 ).Abdomen oval, without markings, sigilla or scuta, covered in short fine setae; female genitalia in ventral view with moderate sclerotisation between petiole and epigastric groove, continuing laterally and posteriorly around tracheal spiracles; pair of narrow transverse sclerotised strips on epigastric groove, possibly associated with copulatory openings ( Figs 14–18 ); venter with two pairs of tracheal spiracles, first pair lateral, second pair posterior to epigastric groove; internally, first pair form lateral sieve tracheae, directed anteriorly ( Figs 19, 22–25 ); second spiracle pair forms two pairs of thick tubular median tracheae projecting anteriorly, each with shorter narrower trachea projecting posteriorly ( Figs 19, 21–25 ) [during genitalic preparation some tracheae, seminal receptacles and membranous sacs broke off]; internal female genitalia comprising single oval or stalk-like median receptacle, expanding into anterior membranous sac ( Figs 19–24 ), usually folded back posteriorly between median tracheae; six spinnerets in typical caponiid arrangement, with ALS, PMS subequal, small, in transverse row, PLS much larger, placed behind ALS, with anal tubercle slightly behind them ( Figs 26–29 ); spigot structure, arrangement unusual for caponiids [most spigots studied by S.E.M. obscured by distal setae around periphery of spigot field, Figs 28–35 ]: ALS of both sexes with dense obliQue ovoid median field of 15–20 small piriform gland spigots ( Figs 26, 27 , 30, 33 ); PMS of males with 12–20 scattered aciniform gland spigots ( Figs 26 , 31 ); PMS of females with single blunt presumptive minor ampullate gland spigot medially, also approximately 15 aciniform gland spigots, most arranged around periphery ( Figs 27 , 34 ); PLS of both sexes with approximately 30 aciniform gland spigots, 15 around periphery, 15 scattered on distal surface ( Figs 32, 35 ). Legs dorsally covered in short curved fine setae, arranged in distinct longitudinal rows dorsally on femora, patellae and tibiae, with naked lines between them ( Figs 1 , 36 ); leg spines absent; legs I more robust than II–IV, particularly the femora, patellae and tibiae, more so in males, legs II slightly thicker than III and IV ( Fig. 1 ); retrolateral patellar indentations slit-like ( Fig. 37 ), broader proximally than distally, running nearly entire length of patellae, with lyriform organ at distal end ( Fig. 38 ); tibiae, metatarsi and tarsi with several trichobothria ( Fig. 39 ); metatarsi and tarsi entire, lacking pseudosegmentation or ventral laminate keel on anterior metatarsi and/or tarsi; metatarsi and tarsi I and II of males with several thicker ventral setae with enlarged bases, resembling cuspules, sometimes on a slight mound, absent in females; tarsal organ oval, with five conspicuous radiating ridges ( Fig. 40 ); three claws present, paired tarsal claws with single row of six to eight teeth on inner margin, unpaired claw smaller, lacking teeth ( Figs 41–43 ); paired claws on anterior tarsi shorter, thicker, with shorter teeth ( Fig. 41 ) than those on posterior tarsi ( Figs 42, 43 ); onychium suboval, without distal projection ( Fig. 43 ). Female palpal tarsus swollen and densely hirsute, particularly distal two-thirds dorsally; palpal claw absent; male palp with oval cymbium, with dense cymbial scopula in distal half, setae quite sparse proximally ( Figs 44, 45 ); tegulum subcircular in ventral view, somewhat conical in lateral view, with tegular apophysis and embolus distally ( Figs 46, 47 ), embolus with associated fine membranous conductor ( Figs 46–62 , 64–66 ).

Distribution: Arid and semi-arid parts of southern Africa ( Botswana, Namibia and South Africa).

Habitat and biology: Ground-dwelling spiders usually collected by pitfall trapping, occasionally also from leaf litter and under rocks. All of the species are associated with arid and semi-arid vegetation biomes, including desert, Nama Karoo, Succulent Karoo, savannah and fynbos. No species have been recorded from the Grassland, Thicket or Forest biomes yet.

Species included: Diploglena arida sp. n., D. capensis Purcell, 1904 , D. dippenaarae sp. n., D. karooica sp. n., D. major Lawrence, 1928 stat. n. and D. proxila sp. n..

Figures

Figs 1–4. Digital microscope photographs of Diploglena arida sp. n. female (1, 2) and male (3, 4) paratypes: (1) dorsal habitus; (2) sternum and mouthparts; (3) chelicerae, posterolateral view, arrow indicating stridulatory file on anterolateral surface of paturon; (4) chelicerae, posterior view, arrow indicating translucent distal lobe. Scale bars: (1) = 5.0 mm; (2) = 1.0 mm; (3, 4) = 0.5 mm.

Figs 5–13. Scanning electron microscope photographs of Diploglena major Lawrence, 1928 female (5–7, 12) and male (8–11, 13): (5) carapace, dorsolateral view; (6) detail of carapace integument; (7) paired eyes; (8) endites, labium and anterior end of sternum; (9) right chelicera, antero-retrolateral view; (10) detail of cheliceral stridulatory file; (11, 12) stridulatory pick on palpal femora; (13) left chelicera, posterior view.Abbreviations: La – laminate keel on mesal margin of chelicera; Lo – lobe on distal margin of chelicera.

Figs 36–47. Scanning electron microscope photographs of Diploglena major Lawrence, 1928 female (36) and male (37–47): (36) patella II, prolateral proximal view; (37) patella III, patellar indentation, retrolateral ventral view, arrow indicating lyriform organ at distal end; (38) patella II, lyriform organ at distal end of patellar indentation; (39) tarsus II, trichobothrial base, dorsal view; (40) tarsus I, tarsal organ, dorsal view; (41) tarsus I, tarsal claws, prolateral view; (42) tarsus III, tarsal claws, retrolateral view; (43) same, ventral view, arrow indicating onychium; (44) palpal cymbium, dorsal view; (45) detail of proximal dorsal cymbial setae; (46) left palp, prolateral ventral view; (47) detail of embolus and tegular apophysis, ventral view.

Figs 48–53. Left male palps of Diploglena arida sp. n. (48–50) and D. capensis Purcell, 1904 (51–53): (48, 51) prolateral view; (49, 52) ventral view; (50, 53) retrolateral view. Scale bars = 0.25 mm.

Figs 54–59. Left male palps of Diploglena dippenaarae sp. n. (54–56) and D. karooica sp. n. (57–59): (54, 57) prolateral view; (55, 58) ventral view; (56, 59) retrolateral view. Scale bars = 0.25 mm.

Figs 60–62.Left male palpof Diploglenamajor Lawrence,1928 in prolateral (60),ventral (61) and retrolateral views (62). Scale bars = 0.25 mm.

Figs 64–66.Left male palp of Diploglena proxila sp. n.in prolateral (64), ventral (65) and retrolateral views (66). Scale bars = 0.25 mm.

Figs14–25.Digital microscope photographsof female Diploglena genitaliain ventral (14–18) and dorsalview (19–25): (14, 19) D. arida sp. n.; (15, 20) D. capensis Purcell, 1904; (16, 21) D. dippenaarae sp. n.; (17, 22, 23) D. karooica sp. n.; (18, 24, 25) D. major Lawrence, 1928. Abbreviations: lt – lateral sieve trachea; mt – anterior branches of paired median tubular tracheae; pb – posterior branches of paired median tubular tracheae; r – seminal receptacle; s – membranous sac extending from seminal receptacle; sd – distance between lateral ends of transverse sclerotised strips; td – distance between lateral ends of posterior tracheal spiracles. Scale bars = 0.5 mm.

Figs 26–27. Digital microscope photographs of spinnerets of Diploglena arida sp. n. male (26) and female (27) paratypes.Abbreviations:Ac – aciniform gland spigots; mAMP – presumed minor ampullate gland spigot; Pi – piriform gland spigots. Scale bars = 0.5 mm.

Figs 28–35. Scanning electron microscope photographs of Diploglenamajor Lawrence, 1928 male (28, 30– 32) and female (29, 33–35):(28,29) spinnerets,posterior view;(30, 33)anterior lateral spinnerets;(31, 34) posterior median spinnerets; (32, 35) posterior lateral spinnerets.Abbreviations:Ac – aciniform gland spigot(s); mAMP – presumed minor ampullate gland spigot; Pi – piriform gland spigot(s).