Mecolaesthus Simon, 1893

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 71-72

Mecolaesthus Simon, 1893

Mecolaesthus / Mecoloesthus Simon 1893b: 482 .

Type species: M. longissimus Simon, 1893 .

Falconia González-Sponga, 2003: 94 . Name preoccupied, replaced by Ayomania González-Sponga, 2005 and by Venezuela Koçak & Kemal, 2008 . Type species: F. multidenticulata González-Sponga, 2003 . Synonymized in Huber et al. (2014a).

Queliceria González-Sponga, 2003: 96 .

Type species Q. discrepantis González-Sponga, 2003 . New synonymy.

Sanluisi González-Sponga, 2003: 100 .

Type species: S. puntiaguda González-Sponga, 2003 . Synonymized in Huber et al. (2014a).

Ayomania González-Sponga, 2005: 108. Replacement name for Falconia González-Sponga, 2003 ; see Falconia above.

Venezuela Koçak & Kemal, 2008: 4 . Unjustified replacement name for Falconia González-Sponga, 2003 ; see Falconia above.

Carbonaria González-Sponga, 2009: 2 .

Type species: C. cordiformis González-Sponga, 2009 . Synonymized in Huber et al. (2014a).

Maimire González-Sponga, 2009: 4 .

Type species: M.tuberculosa González-Sponga, 2009 . Synonymized in Huber et al. (2014a).

Nasuta González-Sponga, 2009: 6 .

Type species: N. grandis González-Sponga, 2009 . Synonymized in Huber et al. (2014a).

Moraia González-Sponga, 2011b:43 .

Type species: M.niquitanus González-Sponga, 2011 . Synonymized in Huber et al. (2014a).

Mecoloesthus – Bonnet 1957: 2742. — Huber 2000: 255 .

Justification of synonymy

The type material of Queliceria discrepantis González-Sponga, 2003 was reexamined, as well as new material collected at the type locality. Morphologically, this species strongly resembles several geographically close species of Mecolaesthus ( M. cornutus Huber, 2000 ; M. tabay Huber, 2000 ; M. mucuy Huber, 2000 ) in its general habitus and carapace coloration (distinctive lateral dark marks restricted to anterior half), and males show the principal putative synapomorphy of the genus (inflated carapace). Preliminary molecular data (J.J. Astrin, B.A. Huber, unpubl. data) also support a close relationship with the congeners listed above and show Queliceria discrepantis as deeply nested among other Venezuelan Mecolaesthus .

Notes

With now 30 Venezuelan species (14 previously described +16 new), Mecolaesthus is the most speciesrich pholcid genus in Venezuela . Only six species have been described from neighboring countries and regions: Trinidad (1), Lesser Antilles (3), Colombia (1), and Brazil (1). This suggests that Venezuela is the distributional center of Mecolaesthus , but at least the Colombian pholcid fauna is poorly known and may include a large number of species.

Of the 14 Venezuelan species described previously, eleven are treated below. For the remaining three Venezuelan species we do not have new data:

Mecolaesthus azulita Huber, 2000 ; type locality “ 20 km SE Azulita (ULA Biol. Res. La Carbonera), Mérida, Venezuela ” ( Huber 2000) [approximately 8.633° N, 71.366° W]; see Notes under M. cordiformis below.

Mecolaesthus hoti Huber, 2000 ; type locality only roughly known: “Rio Baria, Dept. Amazonas, Venezuela ” ( Huber 2000) [between 0.85° N, 66.43° W and 1.47° N, 66.52° W].

Mecolaesthus puntiagudus ( González-Sponga, 2003) , type locality Falcón, Sierra de San Luis, Curimagua [approximately 11.172° N, 69.668° W]. The type specimens (2 ♂♂, 8 ♀♀, 1 juv.; MAGS 1432) have been on loan to another researcher and could not be examined.

The ZFMK collection includes material of six further Venezuelan species, from the states La Guaira, Mérida, Trujillo, and Lara. They are not described here because specimens of only one sex are available.

Operational species groups

Venezuelan Mecolaesthus are here divided into three operational species groups, explicitly based on similarity rather than cladistic analysis. In some cases the specific similarities probably reflect phylogenetic relationships, in others not. Such operational species groups provide a preliminary structure for the known species and they facilitate taxon selection in future phylogenetic analyses.

The cornutus group includes the ten species shown in Fig. 1042. Most species in this group look identical in the field ( Figs 212–219 , 306–311 ); the lateral dark carapace marks are limited to the anterior part; males do not have a longer abdomen than females; male chelicereae are not provided with modified hairs. Within this group, M. peckorum Huber, 2000 ; M. tabay Huber, 2000 ; M. azulita Huber, 2000 ; and M. cordiformis ( González-Sponga, 2009) have extremely similar male chelicerae and female internal genitalia (female of M. azulita unknown). The two species M. chicha Huber sp. nov. and M. parchita Huber sp. nov. fit this group in their morphology but are unusual for their lighter coloration ( Figs 277– 282 ). The two species share strongly banded legs, almost identical procursi and genital bulbs, similar distal cheliceral apophyses and internal female genitalia.

The grandis group includes the eleven species shown in Figs 1043–1044. Males in this group usually have slightly longer abdomens than females (e.g., Figs 429–432 ); male chelicerae are provided with modified hairs; procursi are distally often bifid, divided into a sclerotized and a membranous part (e.g., Figs 348–350 , 390–392 ); males of several species share sclerotized plates anteriorly on the abdomen, ventrally and/or dorsally ( Figs 338 , 430 ). Within this group, M. grandis ( González-Sponga, 2009) ; M. multidenticulatus ( González-Sponga, 2003) ; and M. tuberculosus ( González-Sponga, 2009) are almost indistinguishable even by details of their genitalia. The three species were originally described in three different genera but are likely to be closely related. These three species share with three further species [ M. niquitanus (González-Sponga, 2011) ; M. longipes Huber sp. nov.; M. bienmesabe Huber sp. nov.] a distinctive arrangement of male cheliceral apophyses and modified hairs: a pair of large apophyses and a pair of low elevations, both provided with small modified hairs (e.g., Figs 354 , 396 , 416 ). A similar arrangement but with much stronger hairs occurs in M. trampa Huber sp. nov. and M. lechosa Huber sp. nov. ( Figs 441 , 450 ). The remaining three species ( M. arepa Huber sp. nov., M. pusillus Huber sp. nov., M. alegria Huber sp. nov.), share modified hairs on the male chelicerae but do otherwise not easily fit into this group. The two latter species have identical procursi, very similar male chelicerae and genital bulbs, and they share a pair of dark sclerites in the female internal genitalia ( Figs 473, 476 ).

The longissimus group includes the remaining nine Venezuelan species shown in Figs 1045–1046. This group is certainly polyphyletic, and some species may eventually end up in other or new genera (e.g., M. fallax Huber sp. nov., M. limon Huber sp. nov.). Some species ( M. longissimus Simon, 1893 ; M guasacaca Huber sp. nov.; M. yerbatero Huber sp. nov.) share with representatives of the grandis group a bifid procursus tip ( Figs 500 , 536 , 560 ), but the male chelicerae lack modified hairs. The type species M. longissimus also shares with representatives of the grandis group a longer male than female abdomen. The two species with extremely inflated male prosoma ( M. graphorn Huber sp. nov., M. cachapa Huber sp. nov.) remind of congeners in Trinidad and the Lesser Antilles [ M. arima Huber, 2000 ; M. nigrifrons (Simon, 1894) ; M. lemniscatus (Simon, 1894) ; M. taino Huber, 2000 ] but extremely inflated prosomata are also known from undescribed Colombian species (F. Cala Riquelme, pers. comm. 20 Jul. 2017). In addition, the strong intraspecific variability of carapace inflation (e.g., Figs 510–511 ) makes this a problematic character for phylogeny. The highly aberrant M. fallax is tentatively assigned to Mecolaesthus for the lack of a better solution. Preliminary molecular data (J.J. Astrin, B.A. Huber, unpubl. data) place this species among Mecolaesthus , so it seemed premature to designate a new genus for this species. Finally, M. limon Huber sp. nov. and M. hoti males share the main synapomorphy of the genus (inflated prosoma; Fig. 583 ) but otherwise the two species appear unique and isolated (male genitalia; in M. limon Huber sp. nov. also female genitalia and spines on male femur 1).

Figures

Figs 212–219. Mecolaesthus Simon, 1893; live specimens. 212–214. M. cornutus Huber, 2000; male from Mérida, Mucuy, female with egg sac from Mérida, Escaguey. 215. M. cordiformis (González- Sponga, 2009); male from Mérida, forest near La Carbonera. 216–217. M. mucuy Huber, 2000; male and female from Mérida, Mucuy. 218–219. M. tabay Huber, 2000; male and female from Mérida, El Valle.

Figs 306–311. Mecolaesthus Simon, 1893; live specimens. 306–308. M. piedras Huber sp. nov.; male and female with egg sac from Mérida, Las Piedras. 309–311. M. discrepantis (González-Sponga, 2003); male and female from Trujillo, Laguna Negra.

Figs 277–282. Mecolaesthus Simon, 1893; live specimens. 277–279. M. chicha Huber sp. nov.; male, female, and juvenile from Mérida, between Bailadores and Pregonero. 280–282. M. parchita Huber sp. nov.; male, female, and juvenile from Mérida, between Tovar and Guaraque.

Figs 427–434. Mecolaesthus Simon, 1893; live specimens. 427–428. M. trampa Huber sp. nov.; female with egg sac from Táchira, near La Trampa. 429–432. M. lechosa Huber sp. nov.; male and female from Mérida, Mesa Bolívar (arrows: dark brown book-lung cover and light brown plate close to pedicel). 433–434. M. arepa Huber sp. nov.; males from Táchira, near La Trampa (arrow: median process on carapace).

Figs 348–355. Mecolaesthus grandis (González-Sponga, 2009); from La Guaira, El Limón (type locality; ZFMK Ar 21899–21900). 348–350. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 351–353. Left genital bulb, prolateral, dorsal, and retrolateral views. 354. Male chelicerae, frontal view. 355. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 390–398. Mecolaesthus niquitanus (González-Sponga, 2011); from Trujillo, Laguna Negra (ZFMK Ar 21911–12). 390–392. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 393–395. Left genital bulb, prolateral, dorsal, and retrolateral views. 396–397. Male chelicerae, frontal and lateral views. 398. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 338–345. Mecolaesthus Simon, 1893; live specimens. 338–340. M. grandis (González-Sponga, 2009); male and female with egg sac from La Guaira, El Limón (arrow: brown plate above pedicel opposing carapace inflation). 341–343. M. multidenticulatus (González-Sponga, 2003); male and female with egg sac from Falcón, Curimagua. 344–345. M. tuberculosus (González-Sponga, 2003); male and female with egg sac from Yaracuy, Yurubi National Park.

Figs 410–417. Mecolaesthus bienmesabe Huber sp. nov.; from Lara, between Barquisimeto and Boconó (type locality; ZFMK Ar 21923–24). 410–412. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 413–415. Left genital bulb, prolateral, dorsal, and retrolateral views (arrow: median sclerite on bulbal process). 416. Male chelicerae, frontal view. 417. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 435–443. Mecolaesthus trampa Huber sp. nov.; from Táchira, near La Trampa (type locality; ZFMK Ar 21927–28). 435–437. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 438– 440. Left genital bulb, prolateral, dorsal, and retrolateral views (arrows: distinctive prolateral transversal sclerite). 441–442. Male chelicerae, frontal and lateral views. 443. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 444–452. Mecolaesthus lechosa Huber sp. nov.; from Mérida, Mesa Bolívar (type locality; ZFMK Ar 21930–31). 444–446. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 447–449. Left genital bulb, prolateral, dorsal, and retrolateral views. 450–451. Male chelicerae, frontal and lateral views. 452. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 471–478. Mecolaesthus Simon, 1893; live specimens; epigyna, ventral views and cleared female genitalia, ventral and dorsal views. 471–475. M. pusillus Huber sp. nov.; male from Aragua, Puerto Colombia and female with egg sac from between Maracay and Puerto Colombia; epigynum and cleared female genitalia from Aragua, Puerto Colombia (type locality; ZFMK Ar 21936). 476–478. M. alegria Huber sp. nov.; from Falcón, Santa Cruz de La Alegría (type locality; ZFMK Ar 21938).

Figs 500–505. Mecolaesthus longissimus Simon, 1893; from Aragua, Colonia Tovar (type locality; ZFMK Ar 21940). 500–502. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 503–505. Left genital bulb, prolateral, dorsal, and retrolateral views. Scale lines: 0.2 mm.

Figs 536–544. Mecolaesthus guasacaca Huber sp. nov.; from Falcón, Curimagua (type locality; ZFMK Ar 21947–48). 536–538. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 539–541. Left genital bulb, prolateral, dorsal, and retrolateral views (arrows: three distinctive elements of ventral bulbal sclerite). 542–543. Male chelicerae, frontal and lateral views. 544. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 560–568. Mecolaesthus yerbatero Huber sp. nov.; from Mérida, between Mérida and Barinas (type locality; ZFMK Ar 21950). 560–562. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 563–565. Left genital bulb, prolateral, dorsal, and retrolateral views. 566–567. Male chelicerae, frontal and lateral views. 568. Cleared female genitalia, dorsal view (arrow: tube-like internal structure). Scale lines: 0.3 mm.

Figs 510–513. Mecolaesthus graphorn Huber sp. nov.; from Aragua, Henri Pittier National Park, near La Cumbre (type locality; ZFMK Ar 21943–44). 510–511. Prosomata of large and small males (at same scale). 512–513. Left male pedipalp, prolateral and retrolateral views. Scale lines: 510–511=1 mm; 512–513= 0.5 mm.

Figs 582–588. Mecolaesthus limon Huber sp. nov.; from La Guaira, El Limón (type locality). 582– 585. Live male and female with egg sac. 586–588. Epigynum, ventral view and cleared female genitalia, ventral and dorsal views (ZFMK Ar 21963).