Epicadus Simon, 1895

Machado, Miguel, Teixeira, Renato Augusto & Lise, Arno Antonio, 2018, There and back again: More on the taxonomy of the crab spiders genus Epicadus (Thomisidae: Stephanopinae), Zootaxa 4382 (3), pp. 501-530 : 502-504

Epicadus Simon, 1895

Eripus Walckenaer, 1833: 438 , 441 (Type species Thomisus heterogaster Guérin-Méneville, 1829 , by monotypy); Walckenaer 1837: 541.

Epicadus Simon, 1895: 1052 (replacement name for Eripus Walckenaer, 1833 ; preoccupied by Eripus Dejean, 1829 [ Coleoptera ]); F.O. Pickard-Cambridge 1900: 160; Mello-Leitão 1929: 93; Silva-Moreira and Machado 2016: 283; Machado et al. 2017: 448.

Tobias Simon, 1895: 1053 (Type species Stephanopis camelina O. Pickard-Cambridge, 1869 , by original designation); F.O. Pickard-Cambridge 1900: 161; Mello-Leitão 1929: 80; Machado et al. 2015: 566.

Type species. Epicadus heterogaster ( Guérin-Méneville, 1829) .

Diagnosis. As recently proposed by Machado et al. (2017), the genus Epicadus resembles Epicadinus and Onocolus in the general shape of the male palp, presenting a flat and discoid tegular structure without any apophysis, filiform embolous encircling the tegulum and in the canoe-shaped RTA that is fused to a pointed and usually curved DTA ( Fig. 1E ). However, Epicadus species can easily be recognized and distinguished from other Stephanopinae genera by 1) their globose opisthosoma with pronounced conical opisthosomal projections, 2) the dome-shaped prosoma with elevated thoracic area, 3) presence of a proximal sensorial pit (group of trichobrothria surrounded by duster-shaped setae) located on a dorsal depression of each tibia ( Figs 1A, B ), 4) epigynal plate with posterior folds elevated and joining in the middle to form a median septum ( Fig. 1C ) and 5) by the copulatory ducts presenting a S-shaped configuration ( Fig. 1D ).

Description. Polychromatic and cryptic bark-dwelling spiders with accentuated sexual size dimorphism and body coloration varying from to dark-brown to purple and pink (conservative in males, which are predominantly dark-orange on prosoma and legs and yellow on the opisthosoma). Prosoma as long as wide, in some cases bearing a pair of ocular projections above the ALE and a strong and conical MS on the thoracic portion (as in E. heterogaster and E. rubripes ) ( Fig. 1F ), where a white spot can also be observed; clypeus high (about five times the diameter of AME) and in most of the species with an upside down V-shaped mark. Opisthosoma presenting three ( E. caudatus , E. granulatus , E. pustulosus and E. taczanowskii ), five ( E. camelinus , E. dimidiaster sp. nov., E. pulcher , E. tigrinus sp. nov., E. trituberculatus , E. rubripes ) or seven ( E. heterogaster ) conical projections (less conspicuous in males). Legs I and II stronger and larger than the posterior ones and with conical or blister-shaped setae sockets on the ventral surface of femora; anterior tibiae and metatarsi with three pairs of ventral macrosetae each. Epigynum with copulatory openings exposed or covered by prominences of a median septum formed by the joining of the C-shaped posterior folds of the epigynal plate; two pairs of kidney-shaped spermathecae, varying in size and level of constriction of the upper curve of the copulatory ducts. Male palp with discoid tegulum, filiform embolus and both apophysis (canoe-shaped RTA + pointed and curved DTA) emerging together on the tibiae.

Composition. Eleven species: Epicadus camelinus ( O. Pickard-Cambridge, 1869) , Epicadus caudatus (Mello- Leitão, 1929), Epicadus dimidiaster sp. nov., Epicadus granulatus Banks, 1909 , Epicadus heterogaster (Guérin- Méneville, 1829), Epicadus pustulosus (Simon, 1929) , Epicadus pulcher ( Mello-Leitão, 1929) , Epicadus rubripes Mello-Leitão, 1924 , Epicadus taczanowskii ( Roewer, 1951) , Epicadus tigrinus sp. nov. and Epicadus trituberculatus ( Taczanowski, 1872) .

Updated distribution. From central Mexico to southwestern Argentina ( Fig. 17 ).

Figures

FIGURE 1. Epicadus heterogaster (Guérin-Méneville, 1829). A dorsal gutter of left tibia I (adapted from Silva-Moreira & Machado 2016: fig. 15B) (AMNH 41); B detail of the sensorial pit on tibia I (AMNH); C ventral vieW of the epigynal plate With arroWs indicating the median septum (MSept) and copulatory openings (CO) (adapted from Silva-Moreira & Machado 2016: fig. 15B); D dorsal vieW of female genitalia With detail of the primary (S1) and secondary spermathecae (S2) (adapted from Silva-Moreira & Machado 2016: fig. 15A) (AMNH 41); E retrolateral vieW of the male left palp With arroWs indicating the RTAand DTA(adaptedfrom Silva-Moreira &Machado 2016:fig.15C)(MCTP1772); Scale bars:1 mm (A), 0.05 mm (B), 0.2mm (D), 0.5mm (C, E);F female front WitharroW indicating the medialspire (MS) on thethoracic area (Photo credit:Almir Cândido de Almeida).

FIGURE 17. Data of distribution records of Epicadus species compiled from Machado et al. (2015, 2017); Silva-Moreira and Machado (2016); present study.