Metagonia conica (Simon, 1893)

Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), European Journal of Taxonomy 718, pp. 1-317 : 184-189

Metagonia conica (Simon, 1893)

Figs 657–676, 1021–1022, 1029, 1053

Micromerys conica Simon, 1893b: 472 (Ƌ).

Metagonia conica – Huber 1997c: 342, figs 1a–d, 2a–b (Ƌ).

Notes

The original ‘description’ ( Simon 1893b) is based on two males and consists of a single line describing the shape of the abdomen; it offers neither illustrations nor diagnostic characters. The male was redescribed in Huber (1997c) based on the type material, but the females continued to be unknown. The redescription below is based on 303 newly collected adult males and females from numerous localities, including the type locality.

Preliminary molecular data (J.J. Astrin, B.A. Huber, unpublished) show a relatively deep split between eastern specimens (Aragua, La Guaira, Miranda) and western specimens (Lara, Trujillo). This split is congruent with the limit between two biogeographic regions, the Venezuelan Andes and the Coastal Ranges. However, specimens from all these localities are extremely similar morphologically and they are thus tentatively considered conspecific. The male palps and chelicerae appear identical; the female internal genitalia show minimal differences but these may partly be artifacts of preparation. The most consistent difference refers to the male clypeus (see Variation below).

Diagnosis

Males differ from known congeners by morphology of clypeus ( Fig. 666; two pairs of semitransparent frontal processes and pair of sclerotized apophyses directed downward), by male chelicerae ( Fig. 666; 3–5 globular hairs on each side), by shape of procursus ( Figs 663–665; strongly curved, with distinctive retrolateral S-shaped apophysis), and by female internal genitalia ( Figs 667–668; asymmetric receptacle with duct directed toward anterior; pair of pockets; pore plates very narrow, transversal, and medially fused).

Type material

VENEZUELA – Aragua • Ƌ lectotype (designated in Huber 1997c) and 1 Ƌ paralectotype, MNHN (10502), E. Simon collection number 11022, Colonia Tovar [approximately 10.409° N, 67.294° W], Jan.–Feb. 1888 (E. Simon), examined ( Huber 1997c).

New records

VENEZUELA – Aragua • 4 ƋƋ, 2 ♀♀, ZFMK (Ar 22021), Colonia Tovar , forest above town (10.4144° N, 67.3005° W), 2140 m a.s.l., 8 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 3 ƋƋ, 3 ♀♀, 1 juv., ZFMK (Ar 22022), and 1 Ƌ, 2 ♀♀, 3 juvs in pure ethanol, ZFMK ( Ven 02/100-8), same locality, 26 Nov. 2002 (B.A. Huber) • 3 ƋƋ, 4 ♀♀, ZFMK (Ar 22023), Colonia Tovar, forest at Cerro Picacho (10.4085° N, 67.3088° W), ~ 2250 m a.s.l., 27 Nov. 2002 (B.A. Huber) • 6 ƋƋ, 11 ♀♀, 2 juvs, ZFMK (Ar 22024–25), Henri Pittier National Park, forest near Rancho Grande (10.350° N, 67.684° W), ~ 1150 m a.s.l., 12 Dec. 2002 (B.A. Huber) • 4 ƋƋ, 5 ♀♀, 1 juv., ZFMK (Ar 22026–27), and 3 ♀♀ in pure ethanol, ZFMK (Ven 02/100-31), Henri Pittier National Park , ~ 1 km W Rancho Grande (10.350° N, 67.692° W), 11 Dec. 2002 (B.A. Huber) • 2 ♀♀, ZFMK (Ar 22028), Henri Pittier National Park , ~ 1.5 km NW Rancho Grande (10.358° N, 67.695° W), ~ 1100 m a.s.l., 11 Dec. 2002 (B.A. Huber) • 5 ƋƋ, 4 ♀♀, ZFMK (Ar 22029), Henri Pittier National Park, forest near La Cumbre (10.3575° N, 67.5771° W), 1450 m a.s.l., 20 Feb. 2020 (B.A. Huber, O. Villarreal M.). – La Guaira • 4 ƋƋ, 5 ♀♀, 3 juvs, ZFMK ( Ar 22030), between Colonia Tovar and El Junquito (10.4230° N, 67.2381° W), 1960 m a.s.l., 10 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 12 ƋƋ, 10 ♀♀, ZFMK (Ar 22031–32), and 3 ƋƋ, 6 ♀♀ in pure ethanol, ZFMK (Ven 18-158), El Limón , above road Colonia Tovar-Puerto Cruz (10.4566° N, 67.2548° W), 1535 m a.s.l., 9 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 3 ƋƋ, 3 ♀♀, ZFMK (Ar 22033), and 2 ♀♀ in pure ethanol, ZFMK (Ven 20-172), El Limón , ‘site 2’ (10.4774° N, 67.2819° W), 1235 m a.s.l., forest along stream, 21 Feb. 2020 (B.A. Huber, O. Villarreal M.). – Miranda • 14 ƋƋ, 2 ♀♀, ZFMK (Ar 22034–35), and 2 ƋƋ, 2 ♀♀, 1 juv. in pure ethanol, ZFMK (Ven 18-145), El Ávila National Park , between Sabas Nieves and La Silla (10.5288° N, 66.8546° W), 1850 m a.s.l., 7 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 28 ƋƋ, 12 ♀♀, 1 juv., ZFMK (Ar 22036–37), and 1 Ƌ, 1 ♀ in pure ethanol, ZFMK ( Ven 02/100-4), same locality, 25 Nov. 2002 (B.A. Huber) • 6 ƋƋ, 4 ♀♀, ZFMK (Ar 22038), El Ávila National Park, near La Julia , trail to Rancho Grande (10.5164° N, 66.8089° W), 1460 m a.s.l., degraded forest along small stream, 22 Feb. 2020 (B.A. Huber, O. Villarreal M.) • 3 ƋƋ, 5 ♀♀, 1 juv., MIZA, El Volcán, Topotepuy [10.417° N, 66.851° W, ~ 1450 m a.s.l.], 11–13 Nov. 2019 (O. Villarreal, J. Rodriguez). – Lara • 30 ƋƋ, 33 ♀♀, 5 juvs, ZFMK (Ar 22039–42), and 3 ƋƋ, 7 ♀♀, 3 juvs in pure ethanol, ZFMK (Ven 02/100-63), Yacambú National Park , Sendero Ecológico (9.709° N, 69.580° W), ~ 1550 m a.s.l., 15–16 Dec. 2002 (B.A. Huber, A. Pérez González, O. Villarreal M., B. Striffler, A. Giupponi) • 8 ƋƋ, 4 ♀♀, ZFMK (Ar 22043), and 1 Ƌ, 4 ♀♀ in pure ethanol, ZFMK ( Ven 18- 203), between Barquisimeto and Boconó (9.5906° N, 69.8343° W), 1370 m a.s.l., 20 Nov. 2018 (B.A. Huber, O. Villarreal M.). – Trujillo • 16 ƋƋ, 14 ♀♀, 1 juv., ZFMK (Ar 22044–45), and 1 ♀ in pure ethanol, ZFMK (Ven 18-212), near Boconó , Laguna Negra (9.3054° N, 70.1752° W), 1870 m a.s.l., 21 Nov. 2018 (B.A. Huber, O. Villarreal M.) .

Redescription of male (type locality, ZFMK, Ar 22021)

MEASUREMENTS. Total body length 2.8, carapace width 0.85. Distance PME–PME 170 µm; diameter PME 90 µm; distance PME–ALE 20 µm; AME absent. Leg 1: 29.8 (7.2 +0.4 +7.3+13.3 + 1.6), tibia 2: 4.7, tibia 3: 2.7, tibia 4: 4.4; tibia 1 L/d: 81; all femora approximately same width.

COLOR (in ethanol). Prosoma pale ochre-yellow to whitish, only ocular area black; legs pale ochreyellow, patellae and tibia-metatarsus joints black; abdomen whitish with pale bluish marks dorsally.

BODY. Habitus as in Fig. 658. Ocular area barely raised, each triad on low hump. Carapace without thoracic groove. Clypeus with two pairs of semitransparent frontal processes and pair of sclerotized apophyses directed downward ( Fig. 666). Sternum slightly wider than long (0.60/0.54), unmodified. Abdomen slightly elongate, projecting beyond spinnerets.

CHELICERAE. With four small modified (globular) hairs on each side ( Fig. 666).

PALPS. For general shape, see Huber (1997c: figs 2a–b); coxa unmodified, trochanter with short rounded retrolateral-ventral process; femur short, strongly widened (especially on prolateral-ventral side) but without processes; tibia with retrolateral trichobothrium in very distal position; procursus complex ( Figs 663–665), strongly curved, ventral hinged process distally flat, main part of procursus distally bifid, retrolateral part with short and slender S-shaped apophysis, prolateral part mostly weakly sclerotized and membranous; genital bulb whitish, globular, with embolus ending in transparent spine.

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 8%; prolateral trichobothrium absent on tibia 1; tarsus 1 with ~30 pseudosegments, poorly visible in dissecting microscope.

VARIATION. Prosoma dorsal coloration polymorphic (rather than just variable): of 148 males, 88 (59%) with black ocular area as described above (‘morph 1’; Figs 658, 662), 58 (39%) with black ocular area and black median band (‘morph 2’, Figs 657, 661), and two males without any dark mark (like females). Percentages of different morphs slightly different at eastern and western localities (percentages of ‘morph 1’ in 91 males from eastern localities: 64%; in 54 males from western localities: 50%). Tibia 1 in 120 males: 5.8–8.2 (mean 6.7) (identical mean lengths in males from eastern and western populations). Modified hairs on male chelicerae slightly variable (3–5 on each side, often asymmetric). Clypeus variable: in eastern specimens, inner branch of large apophyses (arrow in Fig. 666) longer than outer branch, in western specimens both branches very similar in length.

Description of female

In general similar to male ( Figs 659–660) but prosoma never with dark dorsal mark. Tibia 1 in 100 females: 4.0–5.3 (mean 4.7) (identical mean lengths in females from eastern and western populations). Epigynum unsclerotized ( Figs 671, 674), only roundish internal receptacle and indistinct pair of small internal pockets visible in uncleared specimens. Internal genitalia asymmetric ( Figs 667–670, 672–673, 675–676), receptacle at posterior end of duct either directed toward right or left side (antisymmetric; both morphs at approximately same frequency); with pair of internal pockets, narrow pore plates in transversal position, medially fused.

Distribution

Known from several localities in the Venezuelan states Aragua, La Guaira, Miranda, Lara, and Trujillo (Fig. 1053).

Natural history

All specimens were collected from the undersides of leaves in humid forests, both on native and introduced plants (e.g., banana). During the day the spiders were pressed against the leaf, and webs were either invisible or limited to a sparse and fine layer of silk closely attached to the leaf surface.