Mecolaesthus alegria Huber, 2020

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 137-139

Mecolaesthus alegria Huber sp. nov.

urn:lsid:zoobank.org:act:DB90E250-72DE-47EB-ACB1-4A4D1C11E22D

Figs 476–478 , 488–493 , 1044

Diagnosis

Easily distinguished from most known congeners (except M. pusillus Huber sp. nov.) by armature of male chelicerae ( Figs 491–492 ; pair of large frontal apophyses set with large modified hairs and pair of simple distal apophyses), by shape of procursus (identical to M. pusillus Huber sp. nov., cf. Figs 479– 481 ; without retrolateral process; tip with pair of dark sclerites connected by transparent membrane), and by epigynum with pair of dark internal structures distinct in uncleared specimens ( Fig. 476 ). From very similar M. pusillus Huber sp. nov. by details of male cheliceral armature (large frontal apophyses directed forward rather than downward; simple distal apophyses with accompanying globular hairs), by shape of bifid distal bulbal sclerite ( Figs 488–490 ; dorsal sclerite much wider in dorsal view), by shape of epigynum ( Fig. 476 ; wider than long), and by internal female genitalia ( Figs 477–478 , 493 ; shape of large lateral ear-shaped structures). From most known congeners (except M. pusillus Huber sp. nov., M. arepa Huber sp. nov., and M. guasacaca Huber sp. nov.) also distinguished by distinct median process posteriorly on male carapace.

Etymology

The species name refers to the type locality; noun in apposition.

Type material

VENEZUELA – Falcón • ♂ holotype, ZFMK (Ar 21938), forest near Santa Cruz de La Alegría (10.8795° N, 68.4949° W), 100 m a.s.l., 15 Feb. 2020 (B.A. Huber, O. Villarreal M., Q. Arias C.) .

Other material examined

VENEZUELA – Falcón • 1 ♀ in pure ethanol (abdomen transferred to male holotype), ZFMK (Ven20- 147), same collection data as for holotype .

Description

Male (holotype)

MEASUREMENTS. Total body length 2.8, carapace width 0.95. Distance PME–PME 90 µm; diameter PME 90 µm; distance PME–ALE 50 µm; diameter AME 20 µm; distance AME–AME 20 µm. Leg 1: 31.1 (7.4 +0.4 +7.6+13.8 + 1.9), tibia 2: 4.9, tibia 3: 3.9, tibia 4: 4.5; tibia 1 L/d: 95.

COLOR (in ethanol). Carapace pale ochre with darker median band and lateral marginal bands not connected posteriorly, ocular area and clypeus dark ochre; sternum ochre-yellow; legs ochre-yellow to light brown, without dark rings; abdomen pale greenish gray, dorsally and laterally densely covered with dark bluish marks, ventrally with small brown mark in gonopore area and bluish median band behind gonopore; book lung covers light brown; with small light brown plate above pedicel.

BODY. Habitus as in M. pusillus Huber sp. nov. (cf. Fig. 471 ). Ocular area slightly raised. Carapace anteriorly with shallow but distinct thoracic groove, posteriorly not inflated but with distinct median process. Clypeus unmodified. Sternum wider than long (0.62/0.40), unmodified. Abdomen slightly elongated, pointed at spinnerets.

CHELICERAE. As in Figs 491–492 , similar to M. pusillus Huber sp. nov. but larger, with pair of large frontal apophyses, each provided with three large modified hairs near tip and two large modified hairs proximally, and pair of simple distal apophyses, each accompanied by globular hair.

PALPS. In general as in M. pusillus Huber sp. nov.; coxa with retrolateral apophysis, trochanter barely modified, femur proximally with large retrolateral-ventral process, dorsally with low hump, distally with ventral conical process; retrolateral trichobothrium on tibia very distal; procursus apparently indistinguishable from M. pusillus Huber sp. nov. (cf. Figs 479–481 ), at basis with dorsal process with obtuse tip, without retrolateral process, with pair of distal sclerites connected by transparent membrane; genital bulb ( Figs 488–490 ) with large process partly membranous/whitish, with distinctive distal sclerite divided into two lobes.

LEGS. Without spines and curved hairs; few vertical hairs; coxa 4 unmodified; retrolateral trichobothrium of tibia 1 at 3%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~35 pseudosegments, fairly distinct.

Female

In general similar to male but carapace posteriorly without median process, abdomen shorter. Tibia 1: 5.1. Epigynum ( Fig. 476 ) simple rectangular plate, anteriorly straight, posteriorly weakly curved, pair of dark internal structures distinct in uncleared specimens; no posterior plate. Internal genitalia ( Figs 477– 478 , 493 ) with large lateral ear-shaped structures, pore plates in lateral position.

Distribution

Known from type locality only, in Venezuela , Falcón (Fig. 1044).

Figures

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 488–493. Mecolaesthus alegria Huber sp. nov.; from Falcón, Santa Cruz de La Alegría (type locality; ZFMK Ar 21938). 488–490. Left genital bulb, prolateral, dorsal, and retrolateral views. 491– 492. Male chelicerae, frontal and lateral views. 493. Cleared female genitalia, dorsal view. Scale lines: 0.2 mm.

Figs 479–487. Mecolaesthus pusillus Huber sp. nov.; from Aragua, Puerto Colombia (type locality; ZFMK Ar 21936). 479–481. Left palpal tarsus and procursus, prolateral, dorsal, and retrolateral views (arrow: ventral femur apophysis). 482–484. Left genital bulb, prolateral, dorsal, and retrolateral views. 485–486. Male chelicerae, frontal and lateral views. 487. Cleared female genitalia, dorsal view. Scale lines: 0.2 mm.