Theridiosoma O. Pickard-Cambridge, 1879

Theridiosoma O. Pickard-Cambridge, 1879: 193 .

Type species: Theridiosoma argenteolum O. Pickard-Cambridge, 1879 (= Theridiosoma gemmosum (L. Koch, 1877)) .

Diagnosis

Males of Theridiosoma resemble those of Andasta Simon, 1895, Tantra gen. nov. and Zoma Saaristo, 1996 by the embolic apophysis divided multiple times (more than three times, see “fragmented” in Coddington 1986 and Labarque & Griswold 2014), forming branches prolaterally and retrolaterally to the embolus (e.g., Zhao & Li 2012: fig. 27d), but Theridiosoma can be distinguished by having more than one prolateral branch (see “bristle-like parts” in Coddington 1986), protruding from beneath the conductor (Fig. 32D–F; see also Coddington 1986; Rodrigues & Ott 2005; Miller et al. 2009; Zhao & Li 2012; Dupérré & Tapia 2017; Suzuki et al. 2020), whereas Andasta have all branches covered by the conductor (Saaristo 2010: fig. 38 6–7), Tantra gen. nov. have one retrolateral branch (Figs 34E, 38E, 42E) and Zoma have one prolateral branch (Miller et al. 2009: fig. 10F; Zhao & Li 2012: fig. 28d; Ballarin et al. 2021: fig. 5c), projecting from beneath the conductor. Females of Theridiosoma can be distinguished from those of other genera by the distal copulatory ducts convoluting antero-posteriorly (Figs 6A, 33D; see also Coddington 1986; Rodrigues & Ott 2005; Miller et al. 2009; Zhao & Li 2012; Dupérré & Tapia 2017; Suzuki et al. 2020).

Description

Males of Theridiosoma have the conductor with heavily sclerotized (i.e., dark) posterior extension (Fig. 32D–F; see also Coddington 1986; Rodrigues & Ott 2005; Miller et al. 2009; Zhao & Li 2012; Dupérré & Tapia 2017; Suzuki et al. 2020) that may have prolateral (e.g., Coddington 1986: figs 154– 156) or retrolateral (e.g., Suzuki et al. 2020: fig. 7e–g) heavily sclerotized projections. In addition, the conductor may have a prolateral, acute and posteriorly elongated apophysis that articulates with it through a membrane (e.g., Suzuki et al. 2020: fig. 7e–g). The embolic apophysis prolateral branches may be filiform, flexible and elongated, with a wide (Fig. 32D–F; e.g., Zhao & Li 2012: fig. 28a–d) or an acute and heavily sclerotized tip (e.g., Suzuki et al. 2020: fig. 7e–g). Females of Theridiosoma have the epigynal plate protruding ventrally, which may be flat (i.e., straight in lateral view; Figs 6B, 33B; e.g., Suzuki et al. 2020: fig. 7d) or domed (i.e., curved in posterior view; e.g., Coddington 1986: figs 138, 143) and may be entire (e.g., Rodrigues & Ott 2005: fig. 6) or divided (e.g., Suzuki et al. 2020: fig. 5a–d), the dorsal epigynal plate exposed protruding from beneath the copulatory opening posteriorly (Fig. 33B–D; e.g., Coddington 1986: fig. 143; Dupérré & Tapia 2017: figs 28–29; Suzuki et al. 2020: fig. 5a, c), massive proximal copulatory ducts (i.e., more than three times the diameter of the distal region), that may be fused (e.g., Lopardo & Hormiga 2015: fig. 123a) or separated (Figs 6A, 33D), with a dorsal patch of gland ducts, and distal copulatory ducts inserting ventromedially posteriorly into the spermathecae (Fig. 6A–B; see also Coddington 1986; Rodrigues & Ott 2005; Miller et al. 2009; Zhao & Li 2012; Dupérré & Tapia 2017; Suzuki et al. 2020). For further genus description details, see Coddington (1986) and Labarque & Griswold (2014).

Remarks

Dupérré & Tapia (2017) suggested that a median apophysis distally acute with an anterior median groove was diagnostic for Theridiosoma, but this character is present in all the members of Theridiosomatinae (see Labarque & Griswold 2014).