Tropicosa, Paredes-Munguía & Brescovit & Teixeira, 2023
publication ID |
https://doi.org/ 10.11646/zootaxa.5228.4.1 |
publication LSID |
lsid:zoobank.org:pub:11C43FF1-C111-4320-A17C-5818A47DE42B |
DOI |
https://doi.org/10.5281/zenodo.7541395 |
persistent identifier |
https://treatment.plazi.org/id/03AD4114-4E5D-751A-B082-796442A1FCAB |
treatment provided by |
Plazi |
scientific name |
Tropicosa |
status |
gen. nov. |
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 View FIGURE 5 , 12c View FIGURE 12 , 19h View FIGURE 19 ) and the expanded anterior part of median septum in females ( Figs 1a View FIGURE 1 , 22f View FIGURE 22 ) 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 View FIGURE 5 , 19a View FIGURE 19 , 28b View FIGURE 28 ), and median apophysis laminar and curved, with ventral process of the median apophysis tapered ( Figs 5d View FIGURE 5 , 11d View FIGURE 11 , 25b View FIGURE 25 ). Females differ from other lycosine genera by the anteriorly expanded median septum ( Figs 1a View FIGURE 1 , 16a View FIGURE 16 ), and wide, triangular hoods ( Figs 21a View FIGURE 21 , 22a View FIGURE 22 ). Both sexes have a longitudinal dark stripe on the sternum ( Figs 9e View FIGURE 9 , 23e View FIGURE 23 , 26e View FIGURE 26 ) and a single longitudinal dark stripe on each chelicera ( Figs 6b View FIGURE 6 , 20b View FIGURE 20 ).
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 View FIGURE 6 , 20a View FIGURE 20 , 26a View FIGURE 26 ). A fusiform dark longitudinal stripe in the sternum is present in both sexes ( Figs 8f View FIGURE 8 , 26e View FIGURE 26 ). 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 View FIGURE 6 , 17b View FIGURE 17 ). 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 View FIGURE 23 ), but not so much in T. chelifasciata comb. nov. ( Fig. 13b View FIGURE 13 ). Cardiac mark lanceolate and surrounded by parallel yellow bands ( Figs 6a View FIGURE 6 , 13a View FIGURE 13 , 17a View FIGURE 17 ). Leg lengths IV>I>II>III, femora darker than tarsi. Male palp has a visible, rounded membranous palea, partially sclerotized ( Figs 19b View FIGURE 19 , 25a View FIGURE 25 ). Tegular lobe is conspicuously strong and spoon-shaped ( Figs 12b View FIGURE 12 , 28e View FIGURE 28 ). A dorsal channel in the median apophysis is visible in apical view and in the expanded bulb ( Figs 12a View FIGURE 12 , 19h View FIGURE 19 ). The median apophysis is laminar, with the ventral projection strong and curved ( Figs 5a View FIGURE 5 , 25a View FIGURE 25 , 28g View FIGURE 28 ). Median apophysis oriented transversally to the cymbium; embolus slender and passing through the dorsal channel of median apophysis ( Figs 4g View FIGURE 4 , 10d View FIGURE 10 , 11e View FIGURE 11 ). A counterclockwise hyaline terminal apophysis, tapering in the left male palp ( Figs 12b View FIGURE 12 , 25b View FIGURE 25 ). Epigyne T-shaped, with median septum expanded anteriorly twice or thrice its narrowest part ( Figs 1a View FIGURE 1 , 7d View FIGURE 7 , 16a View FIGURE 16 ). Transversal septum could be as wide as the expanded part of median septum, as in Tropicosa thorelli comb. nov. ( Figs 22a View FIGURE 22 , 27b View FIGURE 27 ), or narrow as in T. chelifasciata comb. nov. ( Fig. 8a View FIGURE 8 ). Likewise, transversal septum height could be high or low, but is always straight ( Figs 7a View FIGURE 7 , 22e View FIGURE 22 ). Hoods are triangular, parallel, and deep, as wide as the median septum in its expanded part ( Figs 1b View FIGURE 1 , 16a View FIGURE 16 , 21b View FIGURE 21 ). Head of spermatheca rounded ( Fig. 8c View FIGURE 8 ) or triangular ( Fig. 27d View FIGURE 27 ) in dorsal view, spermatheca stalk thinner than the head; vulval chamber absent ( Figs 2b View FIGURE 2 , 22b View FIGURE 22 ).
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 View FIGURE 4 , 5a View FIGURE 5 )......................................................... 3
- Terminal apophysis large, tegular lobe with a pointed apophysis ( Fig. 11a View FIGURE 11 )............................................................................................... Tropicosa chelifasciata (Mello-Leit„o 1943) comb. nov.
3. Subterminal apophysis present, short ( Figs 18b View FIGURE 18 , 25b View FIGURE 25 )......................................................... 4
- Subterminal apophysis absent ( Figs 4b View FIGURE 4 , 5e View FIGURE 5 )........................................... Tropicosa baguala sp. nov.
4 Tegular keel large ( Figs 19c, h View FIGURE 19 )..................................... Tropicosa moesta ( Holmberg 1876) comb. nov.
- Tegular keel tiny ( Figs 24b View FIGURE 24 )....................................... Tropicosa thorelli ( Keyserling, 1877) comb. nov.
5 Head of spermatheca triangular ( Figs 1b View FIGURE 1 , 16b View FIGURE 16 ) and border of the hoods diagonal................................... 6
- Head of spermatheca rounded and border of the hoods straight ( Fig. 8e View FIGURE 8 ).................................................................................................. Tropicosa chelifasciata (Mello-Leit„o 1943) comb. nov.
6 Hoods shallow ( Figs 1a View FIGURE 1 , 16a View FIGURE 16 )............................................................................ 7
- Hoods deep ( Figs 21a View FIGURE 21 , 27d View FIGURE 27 )....................................... Tropicosa thorelli ( Keyserling, 1877) comb. nov.
7 Width of the median septum at the constriction with half the length of transversal septum ( Fig. 16a View FIGURE 16 )................................................................................... 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 View FIGURE 1 , 2d View FIGURE 2 )......................................................................................... Tropicosa baguala sp. nov.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.