Mecolaesthus tabay Huber, 2000

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 82-84

Mecolaesthus tabay Huber, 2000

Figs 218–219 , 257–265 , 271–273 , 1042

Mecolaesthus tabay Huber, 2000: 261 , figs 1040–1043 (♂).

Diagnosis (amendments; see Huber 2000)

Females are easily distinguished from most known congeners by strongly protruding epigynum (similar M. cornutus Huber, 2000 ); from M. cornutus by triangular and much smaller epigynum ( Fig. 271 ; width: ~ 420 µm, vs 580 µm in M. cornutus ); from M. peckorum Huber, 2000 also by triangular rather than oval epigynal plate. Note, however, that the female of M. azulita Huber, 2000 is unknown.

New records

VENEZUELA – Mérida • 1 ♂, ZFMK (Ar 21886), Mucuy, along Laguna El Suero trail (between 8.629° N, 71.039° W and 8.623° N, 71.034° W), ~ 2200–2300 m a.s.l., 24 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 1 ♂, 3 ♀♀, ZFMK (Ar 21887–88), and 1 ♂, 3 ♀♀ in pure ethanol, ZFMK (Ven18- 228, 229), El Valle , cloud forest along river (8.703° N, 71.077° W), 2650 m a.s.l., 25 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 1 ♀, ZFMK (Ar 21889), Monte Zerpa , forest above La Hechicera (8.634° N, 71.163° W – 8.639° N, 71.167° W), 2050–2180 m a.s.l., 26 Nov. 2018 (B.A. Huber, O. Villarreal M., N.A. Sánchez G.) .

Redescription of male (amendments; see Huber 2000)

Habitus as in Fig. 218 . Eye measurements (male from Mucuy): distance PME–PME 120 µm; diameter PME 120 µm; distance PME–ALE 110 µm; distance AME–AME 20 µm; diameter AME 30 µm. Carapace mostly pale ochre-gray, anteriorly brown, ocular area and clypeus also brown; sternum light brown; abdomen pale bluish gray, with dark bluish marks dorsally and laterally, lung plates brown, large dark gray mark at gonopore area and dark bluish median mark behind gonopore. Thoracic furrow shallow but distinct; carapace barely inflated posteriorly. Prolateral trichobothrium present on tibia 1. Pedipalp, procursus, and genital bulb as in Figs 257–264 . Bulb and procursus slightly different in males from El Valle: distal prolateral sclerite of bulb (arrow in Fig. 262 ) slightly shorter and with more slender tip; distal prolateral flap of procursus slightly larger. Tibia 1 in five males (including the two males measured in Huber 2000): 4.6–5.3 (mean 5.0).

Description of female

Females in general similar to males ( Fig. 219 ). Epigynum strongly protruding, in ventral view triangular ( Fig. 271 ). Internal genitalia ( Figs 265 , 272–273 ) very similar to M. cordiformis ( González-Sponga, 2009) (compare Figs 273 and 276 ), with distinctive arc anteriorly protruding (with receptacle) and posteriorly protruding beyond epigynum (thus visible in ventral view); pore plates in almost vertical position, converging and contiguous anteriorly. Tibia 1 in six females: 3.4–3.7 (mean 3.6).

Distribution

Known from several neighboring localities in the Venezuelan state Mérida (Fig. 1042). All localities are at about 2050–2700 m a.s.l.

Natural history

This species occurs in close proximity to several very similar and putatively closely related species; see under M. mucuy and M. cornutus above.

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 257–258. Mecolaesthus tabay Huber, 2000; from Mérida, Mucuy (ZFMK Ar 21886); left male pedipalp, prolateral and retrolateral views. Scale line: 0.3 mm.

Figs 259–265. Mecolaesthus tabay Huber, 2000; from Mérida, Mucuy (male, ZFMK Ar 21886) and from Mérida, El Valle (female, ZFMK Ar 21888). 259–261. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views. 262–264. Left genital bulb, prolateral, dorsal, and retrolateral views (arrow: distal prolateral sclerite, shorter and with more slender tip in males from El Valle). 265. Cleared female genitalia, dorsal view. Scale lines: 0.3 mm.

Figs 271–276. Mecolaesthus Simon, 1893; epigyna, ventral views and cleared female genitalia, ventral and dorsal views. 271–273. M. tabay Huber, 2000; from Mérida, El Valle (ZFMK Ar 21888). 274– 276. M. cordiformis (González-Sponga, 2009); from Mérida, near La Carbonera (ZFMK Ar 21890).