Plato bicolor ( Keyserling, 1886 )

Prete, Pedro H. & Brescovit, Antonio D., 2024, Taxonomic revision of the orb weaving spider genus Plato Coddington, 1986 (Araneae: Theridiosomatidae) with the description of three new species, Zootaxa 5471 (1), pp. 1-32 : 7-10

Plato bicolor ( Keyserling, 1886)

Figures 1 , 5 , 6 , 23

Wendilgarda bicolor Keyserling, 1886:131 , fig. 209 (female holotype from State of Amazonas (no specific location), Brazil, deposited in BMNH, not examined).

Plato bicolor : Coddington, 1986: 33; Lopez, 1996: 192, fig. 9.

Material examined. BRAZIL. Amazonas : Presidente Figueiredo, Cave Maroaga (1°56'6"S, 59°25'19"W), 10♂, 15♀, 25.xi.2013, B. T. Faleiro et al. col. ( UFMG 18217 , SEM); 5♀, 06.v.2006, V. R. Alves col. ( INPA 418 ); Gruta da Judéia (2°3'6"S, 59°58'12"W), 1♂, 10♀, 25.xi.2013, B. T. Faleiro et al. col. ( UFMG 18210 ) .

Diagnosis. Males of Plato bicolor present a digitiform conductor apophysis (fig. 5B), similar to P. ferriferus (fig. 9C), but are distinguished by the elongated apophysis base and by having a distal sulcus (fig. 5D). Females of P. bicolor are recognized by the ventrally projected rectangular dorsal plate (fig. 6C, F) and projected and strongly sclerotized transversal groove in the epigynal plate (fig. 6B, D), occupying half of the ventral area of the plate (fig. 6B).

Description. Male (UFMG 18210). Carapace, sternum, and legs light brown. Chelicerae, labium and endites brown. Abdomen grayish, length: 1.2. Total length: 2. Carapace length: 0.9. Clypeus height: 0.3. Sternum: 0.5 in length and width. Eyes: AME 0.12; AME-AME 0.03; ALE-PLE contiguous (0.05 each); PME-PME separated by 0.06 (PME 0.07). Legs: I femur 1.35/ patella 0.42/ tibia 1.15/ metatarsus 0.76/ tarsus 0.58/ total 4.26; II 1.2/ 0.5/ 1.15/ 0.8/ 0.58/ 4.23; III 0.84/ 0.32/ 0.6/ 0.48/ 0.44/ 2.68; IV 1/ 0.32/ 0.64/ 0.52/ 0.4/ 2.88. Palp. Median apophysis with a very curved and sclerotized tip (fig. 5F). Embolus with a bifid distal apophysis (fig. 5C, F), flattened and hyaline at the tip, covered by the large conductor (fig. 5B, D). Abdomen oval.

Female (UFMG 18210). Coloration as in male. Abdomen oval, length: 1.77. Total length: 2.6. Carapace length: 1.15. Clypeus height: 0.18. Sternum: 0.58 in length and width. Eyes: AME 0.09; AME-AME 0.04; ALE-PLE contiguous (0.07 each); PME-PME separated by the diameter of 1 PME (PME 0.08). Legs: I femur 1.32/ patella 0.48/ tibia 0.94/ metatarsus 0.8/ tarsus 0.54/ total 4.08; II 1.2/ 0.46/ 0.84/ 0.56/ 0.48/ 3.54; III 0.88/ 0.36/ 0.6/ 0.45/ 0.46/ 2.75; IV 1.05/ 0.36/ 0.8/ 0.58/ 0.5/ 3.29. Epigynum. Dorsal plate posterior to spermathecae (fig. 6D). Epigynal plate,with tapered and projected lateral margins (fig. 6B). Well-marked central pore, transversal groove, and support (fig. 6B).

Variation. 10 males: total length: 1.6–2; carapace: 0.7–1; femur I: 1.12–1.35. 10 females: total length: 2.34– 2.6; carapace: 0.97–1.15; femur I: 1.31–1.5.

Distribution. Known only for Caverna Maroaga and Gruta da Judéia, both in Presidente Figueiredo, state of Amazonas, Brazil (fig. 23).

Figures

FIGURE 1. Palp of Plato. A, B, Plato bicolor from Cave Maroaga, Presidente Figueiredo, Amazonas, Brazil, SEM; C, Plato ferriferus from Parauapebas, Pará, Brazil, SEM; A, mesal view; B, ventral view, expanded; C, cymbium, ventral view. Structures are marked with different colors.Abbreviations, AL, alveolus. C, conductor. CA, conductor apophysis. CL, cymbial lamella. Cy, cymbium. E, embolus. EA, embolic apophysis. MA, median apophysis. O, embolic opening. PC, paracymbium. ST, subtegulum. T, tegulum. Scales: A–C, 0.2.

FIGURE 5. Plato bicolor, from Cave Maroaga, Presidente Figueiredo, Amazonas, Brazil. A, male body, dorsal view; B–E, male palp, left; B, mesal view; C, embolus, distal view, illustration; D, ventral view, SEM; E, prolateral view, SEM; F, male palp, right, mirrored, ventral view, SEM.Abbreviations, C, conductor. CA, conductor apophysis. Cy, cymbium. E, embolus. EA, embolic apophysis. MA, median apophysis. O, embolic opening. PC, paracymbium. ST, subtegulum. T, tegulum. Scales: A, 1; B, C, 0.2; D, E, 0.1; F, 0.2.

FIGURE 6. Plato bicolor, from Cave Maroaga, Presidente Figueiredo, Amazonas, Brazil. A, female body, dorsal view; B–F, epigynum; B, ventral view, clarified; C, illustration, dorsal view; D, lateral cut, clarified; E, dorsal view, SEM; F, posterior view, SEM. Abbreviations, At, atrium. CD, copulatory ducts. CP, central pit. DP, dorsal plate. FD, fertilization ducts. S, spermathecae. Su, epigynal support. TG, transversal groove. Scales: A, 1; B, C, D, 0.2; E, F, 0.1.

FIGURE 23. Distribution of records of Plato (South America).