Orthobula sudamericana Piñanez & Munévar, 2022

Piñanez Espejo, Yolanda M. G., Munévar, Ana & Kochalka, John A., 2022, A new species of Orthobula Simon, 1897 (Araneae: Trachelidae) from South America, Zootaxa 5124 (1), pp. 75-80 : 76-78

Orthobula sudamericana Piñanez & Munévar , sp. nov.

Figs 1–2

Type material. Holotype ♂: ARGENTINA: Misiones : Puerto Iguazú, Alto Paraná (25°48’09.8”S, 54°30’37.9”W), Pine trees ( Pinus taeda ), mature plantations, 20.II.2017, leg. A. Munévar ( IBSI _ ARA0070 ).

Paratype: 1♀, same data as the holotype ( IBSI _ ARA0070 a) .

Etymology. The specific name is Spanish and refers to the discovery of a species of Orthobula in South America.

Diagnosis. Females of the new species are most similar to O. chayuensis Yang , Song & Zhu, 2003, but can be distinguished from the latter by the dark abdomen with pale yellow pattern, and by the straight and parallel insemination ducts. The male resembles O. charitonovi Mikhailov, 1986 but can be distinguished by the U-shaped sperm duct located centrally and the serrated retrolateral femoral margin.

Description. Carapace reddish-brown, abdomen pale yellow with dark pattern; centrally with four large invaginate sigilla, less sclerotized in males ( Fig. 1a ; Fig. 2a ). Strongly sclerotized yellow sternum covered with pits. Eyes in two rows (4:4), anterior row straight, posterior row recurved in dorsal view; eye diameters variable. ALE and AME rounded, PLE and PME ovoid. Legs I and II with 2 rows of strong spines ventrally on the tibia, metatarsus and tarsus; legs III and IV without spines. Leg spination: tibia I v5-5, tibia II v4-4; metatarsus I v3-3, metatarsus II v4- 4 in females and v3- 3 in males; tarsus I and II v3- 3 in females and v2- 2 in males. Leg formula: ♀ 4123, ♂ 1423.

Holotype ♂: tegulum pear-shaped, apically narrow and wider at base ( Fig. 1c ). Embolus short, slightly thorn-like ( Fig. 1c ). Palpal tibia with small apophysis on retrolateral margin ( Fig. 1d ). Palpal femur with serrated retrolateral margin and with very small ventral distal apophysis ( Fig. 1c —dva). Carapace 0.950 long, 0.530 wide in cephalic area, 0.780 wide in thoracic area. Abdomen 0.880 long, 0.760 wide. Palpal femur 0.187, tibia 0.127, patella 0.148, cymbium 0.363. Abdomen covered by dorsal scutum, ventral sclerite subtriangular, broader than long ( Fig. 1a, b ). Eye sizes and interdistances: AME 0.047, ALE 0.048, PME 0.080, PLE 0.068; AME–AME 0.043, AME–ALE 0.038, ALE–PLE 0.043, PME–PME 0.055, PME–PLE 0.042. MOQ 0.180 wide.

Paratype ♀: Same as male, except abdominal dorsal scutum and ventral sclerite absent; venter with two paired rows of small oval sclerites. Carapace 0.930 long, 0.485 wide in cephalic area, 0.771 wide in thoracic area. Abdomen 1.160 long, 1.040 wide. Epigyne with primary receptacles 0.081 long, 0.075 wide; secondary receptacles 0.158 long, 0.191 wide. Distance between copulatory openings 0.023; span between lateral edges of copulatory openings 0.106; span between lateral edges of primary receptacles 0.180. Copulatory openings close together (no space between them) ( Fig. 2d —co). Vulva with two pairs of receptacles, primary receptacles transverse, ovoid and strongly sclerotized; secondary receptacles (bursae) massive, egg-shaped, weakly sclerotized ( Fig. 2e–f ). Eye sizes and interdistances: AME 0.037, ALE 0.048, PME 0.072, PLE 0.062. AME–AME 0.030, AME–ALE 0.021, ALE–PLE 0.039, PME–PME 0.051, PME–PLE 0.039. MOQ 0.180 wide.

Other material examined. ARGENTINA: Misiones: Puerto Iguazú: Reserva Privada Alto Paraná, 25°47’14.6”S 54°21’25.1”W, Pine trees ( Pinus taeda ), mature plantations, Winkler bag, leg. A. Munévar, 12– 16.I.2017, 1♂ ( IBSI _ ARA0070 b) . PARAGUAY: Alto Paraguay: Madrejón, Parque Nacional Defensores del Chaco , 20°37’44.8”S 59°53’27.7”W, leg. J. Kochalka, 10.IX.1982, 8♂ 6♀ 7 imm. (IBNP-Invert.-JAK-CR 2799); Same collector and coordinates (4:00 pm), 11.IX.1982, 1♂ (IBNP-Invert.-JAK-CR 2800); Same data, 10.IX.1982, 2♂ 1♀ 2 imm. (IBNP-Invert.-JAK-CR 2802) . Amambay: Parque Nacional Cerro Corá , 22°39’59.9”S 55°59’12.5”W, sifting leaf litter, leg. J. Kochalka, 29. V –3. VI.1982, 4♀ (IBNP-Invert.-JAK-CR 2801) . Itapúa: Alto Verá, Parque Nacional San Rafael , 26°30’33.0”S 55°47’24.4”W, natural grassland, pitfall, leg. Y. Piñanez, 2–3.IX.2016, 2♀ (IBNP-Invert.-JAK-CR 2803); Same data, 8–10.XI.2016, 1♂ (IBNP-Invert.-JAK-CR 2804) . Boquerón: Parque Nacional Tte. Enciso , 21°12’36.4”S 61°39’20.5”W, leg. B.B. Barrios & B. Garcete, 7.VIII.1994, 1♂ (IBNP-Invert.- JAK-CR 2805) . San Pedro: San Estanislao ( Santaní ), 24°40’34.7”S 56°24’01.0”W, semi-natural riparian forest, leg. W. Jahn, 5–10.III.1991, 1♀ (IBNP-Invert.-JAK-CR 2806) .

Natural history. Orthobula sudamericana sp. nov. is found at elevations ranging from 162 to 300 meters in the tropical and subtropical region of South America. Examined specimens were collected in the Dry Chaco, Cerrado and Alto Paraná Atlantic Forest ecoregions in Argentina and Paraguay ( Morrone 2014) ( Fig. 3 ). Specimens from all three ecoregions were found in the soil and leaf litter layer. These strata vary in their characteristics relative to the vegetation structure of each habitat type. Sites from the Dry Chaco exhibit a mosaic of xeric forest and open vegetation where the soil is usually dry and bare. In contrast, the Alto Parana Atlantic Forest receives about four times as much precipitation annually (~ 1600-2000 mm) and exhibits several vegetation strata (3 to 5) ( Morellato & Haddad 2000). We consider that O. sudamericana sp. nov. may be a non-native species that was possibly introduced from the Afrotropical, south Palaeartic or Oriental biogeographical realms.

Figures

FIGURE 1. Orthobula sudamericana sp. nov., holotype male (IBSI_ARA0070): a Habitus, dorsal view; b Habitus, ventral view; c Male right palp in dorsal view; d Male palp in prolateral view (expanded palp); e Male right palp in prolateral view (not expanded). Abbreviations: e: embolus, pf: palpal femur, pt: palpal tibia, sd: sperm duct, t: tegulum, dva: femoral distal ventral apophysis. Scale bar: 0.1 mm.

FIGURE 2. Orthobula sudamericana sp. nov., paratype female (IBSI_ARA0070a): a Habitus, dorsal view; b Habitus, ventral view; c Abdomen, ventral view; d Uncleared epigyne, ventral view; e Cleared epigyne, dorsal view; f Cleared epigyne, ventral view. Abbreviations: co: copulatory openings, pr: primary receptacle, sr: secondary receptacle. Scale bar: 0.1 mm.

FIGURE 3. Distribution of Orthobula sudamericana sp. nov. (white circles) in South America.