Tropicosa Paredes-Munguía & Brescovit & Teixeira 2023, gen. nov.
Creators: name: Paredes-Munguía, Williams
name: Brescovit, Antonio D.
name: Teixeira, Renato A.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Lycosidae
Tropicosa

description: Tropicosa gen. nov.
Type species. Lycosa moesta Holmberg, 1876
Etymology. The genus name is a combination of “Tropical”, referring to the distribution of all four species, and “cosa”, a common ending of lycosid genera.
Justification and putative synapomophies. The Alopecosa moesta lineage emerged clearly as a different grouping, distant from Nearctic Alopecosa (Piacentini & Ramirez 2019). The laminar median apophysis, curved ventral process, the visible well sclerotized tegular lobe in males (Figs 5b, 12c, 19h) and the expanded anterior part of median septum in females (Figs 1a, 22f) will be treated here as synapomorphies. These characters, observed in two Neotropical lycosids (Schizocosa chelifasciata and Lycosa thorelli) and in a new species, justifies their grouping.
Diagnosis. Tropicosa gen. nov. can be recognized by the following combination of characters: males with tegular lobe spoon-shaped and strongly sclerotized (Figs 5b, 19a, 28b), and median apophysis laminar and curved, with ventral process of the median apophysis tapered (Figs 5d, 11d, 25b). Females differ from other lycosine genera by the anteriorly expanded median septum (Figs 1a, 16a), and wide, triangular hoods (Figs 21a, 22a). Both sexes have a longitudinal dark stripe on the sternum (Figs 9e, 23e, 26e) and a single longitudinal dark stripe on each chelicera (Figs 6b, 20b).
Compared to other Neotropical lycosids, this combination of characters is unique. Considering the shape and size of the terminal apophysis, species of Tropicosa resemble species of Pavocosa Roewer, 1960 or Hogna Simon, 1885. However, both genera have a small tegular lobe with a short membrane at its apex, and Pavocosa possesses a straight ventral process of median apophysis, slightly curved in Hogna. Under field conditions, species of Tropicosa are recognizable by the carapace dark-brown and longitudinal dark stripes on each chelicera.
Description. Small wolf spiders, females larger than males (females 8.00–14.67; males 6.33–12.78). Carapace brown, both median and submarginal bands yellow (Figs 6a, 20a, 26a). A fusiform dark longitudinal stripe in the sternum is present in both sexes (Figs 8f, 26e). First row of eyes equal and slightly procurved, shorter than the second, AME slightly larger than ALE. A black ocular area covered by a group of short white setae (Figs 6d, 17b). Carapace piriform, relatively wider in females than in males. Chelicerae with three teeth in the retromargin of the fang furrow, decreasing in size from the distal to basal teeth; promargin with three teeth, the median the bigger. Chelicerae creamy with a single longitudinal dark stripe continued from clypeus, conspicuous in fresh specimens of T. thorelli comb. nov. (Fig. 23b), but not so much in T. chelifasciata comb. nov. (Fig. 13b). Cardiac mark lanceolate and surrounded by parallel yellow bands (Figs 6a, 13a, 17a). Leg lengths IV>I>II>III, femora darker than tarsi. Male palp has a visible, rounded membranous palea, partially sclerotized (Figs 19b, 25a). Tegular lobe is conspicuously strong and spoon-shaped (Figs 12b, 28e). A dorsal channel in the median apophysis is visible in apical view and in the expanded bulb (Figs 12a, 19h). The median apophysis is laminar, with the ventral projection strong and curved (Figs 5a, 25a, 28g). Median apophysis oriented transversally to the cymbium; embolus slender and passing through the dorsal channel of median apophysis (Figs 4g, 10d, 11e). A counterclockwise hyaline terminal apophysis, tapering in the left male palp (Figs 12b, 25b). Epigyne T-shaped, with median septum expanded anteriorly twice or thrice its narrowest part (Figs 1a, 7d, 16a). Transversal septum could be as wide as the expanded part of median septum, as in Tropicosa thorelli comb. nov. (Figs 22a, 27b), or narrow as in T. chelifasciata comb. nov. (Fig. 8a). Likewise, transversal septum height could be high or low, but is always straight (Figs 7a, 22e). Hoods are triangular, parallel, and deep, as wide as the median septum in its expanded part (Figs 1b, 16a, 21b). Head of spermatheca rounded (Fig. 8c) or triangular (Fig. 27d) in dorsal view, spermatheca stalk thinner than the head; vulval chamber absent (Figs 2b, 22b).
Species composition. Four species, Tropicosa baguala sp. nov., T. moesta comb. nov., T. thorelli comb. nov. and T. chelifasciata comb. nov.
Distribution. From north and central Colombian Andean region (Santander, Boyacá, Cundinamarca) to the northeastern (Salta, Santiago del Estero) and central Argentina (Santa Fé, Buenos Aires).
Identification key for Tropicosa species
1. Males.............................................................................................. 2
- Females............................................................................................. 5
2. Terminal apophysis short, sword shaped (Figs 4b, 5a)......................................................... 3
- Terminal apophysis large, tegular lobe with a pointed apophysis (Fig. 11a)............................................................................................... Tropicosa chelifasciata (Mello-Leit„o 1943) comb. nov.
3. Subterminal apophysis present, short (Figs 18b, 25b)......................................................... 4
- Subterminal apophysis absent (Figs 4b, 5e)........................................... Tropicosa baguala sp. nov.
4 Tegular keel large (Figs 19c, h)..................................... Tropicosa moesta (Holmberg 1876) comb. nov.
- Tegular keel tiny (Figs 24b)....................................... Tropicosa thorelli (Keyserling, 1877) comb. nov.
5 Head of spermatheca triangular (Figs 1b, 16b) and border of the hoods diagonal................................... 6
- Head of spermatheca rounded and border of the hoods straight (Fig. 8e).................................................................................................. Tropicosa chelifasciata (Mello-Leit„o 1943) comb. nov.
6 Hoods shallow (Figs 1a, 16a)............................................................................ 7
- Hoods deep (Figs 21a, 27d)....................................... Tropicosa thorelli (Keyserling, 1877) comb. nov.
7 Width of the median septum at the constriction with half the length of transversal septum (Fig. 16a)................................................................................... Tropicosa moesta (Holmberg 1876) comb. nov.
- Width of the median septum at the constriction equal to two thirds the length of transversal septum (Figs 1a, 2d)......................................................................................... Tropicosa baguala sp. nov.
description: Published as part of Paredes-Munguía, Williams, Brescovit, Antonio D. & Teixeira, Renato A., 2023, Tidying things up: Tropicosa, a new Neotropical wolf spider genus (Araneae: Lycosidae: Lycosinae), pp. 351-393 in Zootaxa 5228 (4) on pages 353-354, DOI: 10.11646/zootaxa.5228.4.1, http://zenodo.org/record/7539988