Metagonia beni, HUBER, 2000

HUBER, BERNHARD A., 2000, New World Pholcid Spiders (Araneae: Pholcidae): A Revision At Generic Level, Bulletin of the American Museum of Natural History 2000 (254), pp. 1-348 : 67-73

publication ID

https://doi.org/ 10.1206/0003-0090(2000)254<0001:NWPSAP>2.0.CO;2

persistent identifier

https://treatment.plazi.org/id/03ACD276-8F16-FFA1-FF78-FC8743B33D29

treatment provided by

Felipe

scientific name

Metagonia beni
status

sp. nov.

Metagonia beni View in CoL , new species Figures 249 View Figs 255

TYPES: Male holotype, 33 7♀ paratypes from 16.8 mi SW Yucumo (~ 15°23'S, 66°59'W), Dept. Beni, Bolivia GoogleMaps ; ~ 500 m elev., Nov. 15 19, 1989 (J. Coddington, C. Griswold, D. Silva, S. Larcher, E. Penaranda), in USNM .

ETYMOLOGY: Named for the Bolivian state Beni. The specific name is a noun in apposition.

DIAGNOSIS: Typical representative of group 2 above. Very similar to M. uvita (from Costa Rica!), distinguished by the larger patch of modified hairs on the male chelicerae, the broader distal apophyses on the male chelicerae, and the female internal genitalia (compare figs. 253, 255 with figs. 8c, 9 in Huber, 1997a). Direct comparison of M. uvita specimens with the present material showed no perceptible differences in palpal structure (minor differences between figs. 450 451 herein and figs. 8d e in Huber, 1997a, result largely from different angles of view, or are artifacts).

MALE (holotype): Total length 1.9, carapace width 0.63; leg 1: 17.2 (4.3+0.3 +4.3+7.1+1.2), tibia 2: 2.4, tibia 3: 1.3, tibia 4: 2.5; tibia 1 l/d: 80. Habitus as in fig. 249; entire prosoma whitish, distance PME- ALE very small (almost touching). Clypeus not sexually modified. Chelicerae slightly darker than prosoma, with light brown area covered with globular hairs and pair of distal apophyses (fig. 253). Palps pale ochre-yellow, only procursus with black elements; coxa and femur without apophyses; procursus complex (figs. 250 252), with hinged process; bulb simple, as typical for genus. Legs whitish, without darker rings, almost all hairs missing; retrolateral trichobothrium on tibia 1 apparently missing in holotype, in paratype at 8.8%; tarsus 1 with ~ 15 pseudosegments. Opisthosoma cylindrical (fig. 249), dirty white with slightly darker smudges dorsolaterally (~ 8 on each side).

VARIATION: Tibia 1 in three male paratypes: 3.7 4.1.

FEMALE (paratypes): Tibia 1 (N = 6) 3.3 3.9 (x¯ = 3.5). In general very similar to male. Epigynum extremely simple externally, only with receptacle shining through cuticle (fig. 254); internal genitalia as shown in fig. 255, with distinctly asymmetrical receptacle(?).

DISTRIBUTION: Known from Peru (Huánuco, Madre de Dios) and northern Bolivia (Beni).

MATERIAL EXAMINED: BOLIVIA: Beni: 16.8 mi SW Yucumo : types above. PERU: Huánuco: Dantas-La Molina, SW Puerto Inca (9°38'S, 75°00'W), 270 m elev., May 28 and June 1, 1987 (2 vials; D. Silva), 33 in MUSM. Madre de Dios: Parque Nacional Manú, Zona Reservada Pakitza (11°56'S, 71°17'W), 356 m elev., Apr. 24 29, Sept. 26 30, and Oct. 1 19, 1991 (3 vials; D. Silva), 33 2♀ in USNM GoogleMaps ; Pakitza, Rio Manú (12°07'S, 70°58'W), 250 m elev., Sept. 22, 1988 (T. L. Erwin & B. D. Farrel), 13 in USNM GoogleMaps .

Metagonia mariguitarensis (González-Sponga, 1998) , new combination Figures 256 View Figs 267

Anomalaia mariguitarensis González-Sponga, 1998: 25 27, figs. 21 32.

TYPES: Male holotype, 43 12♀ paratypes from Mariguitar , Dept. Simon Bolívar, Edo. Sucre, Venezuela ; 10 m elev., Dec. 22, 1986 (A. Campos), in collection González-Sponga (1004a, b) (not examined).

DIAGNOSIS: Representative of group 2 above (cheliceral apophyses!); easily distin- guished from congeners by the asymmetrical palps (figs. 257 258), the armature of the male chelicerae with their lateral pointed protrusions (fig. 259), and the shape of the asymmetrical structures in the female internal genitalia (figs. 262 263).

MALE (Roraima, Brazil): Total length 2.0, carapace width 0.77; leg 1 missing, tibia 2: 2.5, tibia 3: 1.6, tibia 4: 2.5. Habitus as in fig. 256. Carapace ochre-yellow, with triangular brown mark posteriorly; six eyes in two triads on brown ocular area, distance PME- ALE about 20% of PME diameter. Clypeus barely modified, only with pair of darker humps; sternum whitish. Chelicerae with distinctive lateral cone-shaped protrusions, frontal apophyses and patches of globular modified hairs (fig. 259). Palps asymmetrical in every aspect except coxa and (apparently) trochanter (figs. 257 258, 260 261): femur of right side longer and with differently shaped ventral apophysis, tibia of right side much larger, sclerotized rod (= main branch of procursus) of right side much stronger and longer, hinged process of right side long and slender, that of left side shorter but with complicated sclerotized tip, bulbs of both sides approximately same size, but embolus of left side shorter and much broader (figs. 260 261) (in all four males examined it was the right palp that was enlarged; the same applied to the five males studied by González- Sponga). Legs ochre-yellow, with dark brown patellae and tibia-metatarsus joints; most hairs missing. Opisthosoma grayishochre, with about six pairs of blackish spots dorsally, pointed posteriorly (not bifid).

FEMALE (Roraima, Brazil): Tibia 1 in two specimens: 3.8, 4.0. In general very similar to male, but opisthosoma projecting even far- ther beyond spinnerets, two to eight pairs of spots dorsally on opisthosoma, carapace with brown X mark and median line on ocular area. Epigynum very simple externally, with broad scape, asymmetrical structures shining through cuticle (fig. 263; in all six females examined the dark round structure was on the right side). Internally with apparently symmetrical uterus externus and valve, but asym-

metrical system of ducts(?) and receptacle(?) (fig. 262).

DISTRIBUTION: Known from Venezuela (Sucre), northern Brazil (Roraima), and Peru (Loreto, Huánuco, Madre de Dios; see Notes below).

MATERIAL EXAMINED: BRAZIL: Roraima: Ilha Maracá, Jan. 31 Feb. 14, 1992 (A. A. Lise), 13 4♀ in MCP. PERU (see Notes be- low): Loreto: Rio Samiria (04°43'S, 74°18'W), June 24, 1990 (T. Erwin et al.), 13 1♀ in MUSM GoogleMaps ; Huánuco: Bosque Nacional A. von Humboldt, El Caobal , July 31, 1986 (D. Silva), 13 in MUSM ; Madre de Dios: Pakitza, Rio Manú (12°07'S, 70°58'W), 250 m elev., Sept. 22, 1988 (T. Erwin & B. D. Farrel), 13 1♀ in USNM GoogleMaps .

NOTES: While the specimens from Roraima are very prabably conspecific with the type material, the specimens from Peru are herein assigned tentatively. There are some differences suggesting they might actually belong to a separate species: the frontal apophyses on the male chelicerae are slightly more pointed; the pattern on the carapace of the male resembles that of the females from Roraima described above; the opisthosoma has many spots dorsally, and is less pointed posteriorly; the right palp is even more en- larged (fig. 265, the left palp is about the same size as in male from Roraima); the femur apophyses differ slightly (compare figs. 260 261 with 264 265); in the left palp the sclerotized rod is shorter (compare figs. 260, 264; note that the apparent difference in the tips of the hinged processes shown in figs. 260 and 264 is mostly artificial, due to slightly different angles of view); the bulb is clearly dimorph in size (figs. 266 267; in the males from Huánuco and Madre de Dios, the bulb of the large palp is even smaller than in the male from Loreto, illustrated here); the left embolus is even broader and more sclerotized (fig. 266); the pore plates in the female uterus externus appear more elongate. Measurements of male from Loreto: total length 2.2, carapace width 0.87; leg 1: 19.1 (4.8+0.3+4.7+8.0+1.3), tibia 2: 2.9, tibia 3: 1.7, tibia 4: 2.8; tibia 1 l/d: 54; retrolateral trichobothrium of tibia 1 at 14%; tarsus 1 with ~ 20 pseudosegments. Tibia 1 in males from Huánuco and Madre de Dios: 5.3 (both). Female tibia 1: 4.1.

González-Sponga (1998) noted the presence of only one trichobothrium on the male palpal tibia. I checked the four males examined and found two trichobothria on all palpal tibiae, as in all pholcids examined. However, the distal (retrolateral) trichobothrium of the right palp appears to tend toward reduction (the hair base is smaller) and may actually be absent in the type material.

Metagonia unicolor (Keyserling, 1891) , new combination Figures 268 View Figs 270

Spermophora unicolor Keyserling, 1891: 178 179, figs. 123, 123a b. Moenkhaus 1898: 88. Mello-Leitao, 1918: 110 111. (Both Moenkhaus and Mello-Leitao simply translated Keyserling s original description, without adding new information.) Mello-Leitao, 1947a: 3; fig. 50 (see Notes below).

TYPE: Female holotype from Serra Vermelha , Rio de Janeiro, Brazil ; no date (E. A. Göldi), in BMNH (1890.411.8340), examined .

NOTES: Without a male the species cannot be diagnosed. Mello-Leitao s (1947a) illustration of the palp is very unlikely from a conspecific male, given the large number of (mostly undescribed) very similar species in southeastern Brazil, and the fact that Mello- Leitao probably did not consult the type. The present brief redescription and illustrations may help identify the species when males and females are found together. Metagonia unicolor might be close to M. furcata , n. sp., and thus a representative of group 5, but it might also be a representative of group 2. In any case, the main point in the context of the present paper is that this species is very probably a Metagonia , supporting the statement that Spermophora is not a natural element in America (Brignoli, 1974; Huber, 1998d).

FEMALE (holotype): Total length 1.6, carapace width 0.6; leg 1: (2.0+0.2+2.1+2.4, tarsus missing), tibia 2: 1.3, tibia 3: 0.8, leg 4 missing; tibia 1 l/d: 33. Habitus as in figs. 268 269, entire spider pale ochre-yellow, internal genitalia apparently asymmetrical (fig. 270; as common in Metagonia , but so far not known in any other pholcid genus).

DISTRIBUTION: Known only from type locality.

MATERIAL EXAMINED: BRAZIL: Rio de Janeiro: type above.

Metagonia furcata , new species

Figures 271 View Figs 278

TYPES: Male holotype, 1♀ paratype, and one juvenile from Santa Teresa , Espírito Santo, Brazil ; Jan. 26, 1959 (A. M. Nadler), in AMNH .

ETYMOLOGY: The species name is an adjective, referring to the fork-shaped clypeal apophysis in the male.

DIAGNOSIS: Easily distinguished from all known congeners by the male frontal armature, especially the long frontal fork (figs. 271 273); also by the armature on the male chelicerae (figs. 272 273), and the shape of the male procursus (figs. 274 276).

MALE (holotype): Total length 1.5, carapace width 0.6: leg 3 (all others loose): 4.0 (1.1+0.2+1.0+1.2+0.5), femur 4: 1.8. Carapace ochre-yellow, without thoracic groove; six eyes in two triads (fig. 272); distance PME-ALE about 25% of PME diameter. Clypeus with dark brown sculpture and ochre-yellow fork (figs. 271 273). Sternum pale ochre-yellow. Chelicerae light brown, with several globular hairs on frontal humps, prominent lateral apophyses, and stridulatory ridges laterally (figs. 272 273). Palps as in fig. 274; coxa without retrolateral apophysis, femur extremely voluminous (fig. 274), procursus complex (figs. 274 276), resembling that of M. globulosa , n. sp. (cf. figs. 286 287); bulb consisting of simple globular part and tubular embolus ending in spine. Legs pale ochre-yellow, without rings; tarsus 3 with ~ 10 pseudosegments. Opisthosoma monochromous pale gray, shape as in M. unicolor (cf. figs. 268 269).

FEMALE (paratype): Habitus as in male; all legs missing or loose. Without any dark marks. Without sclerotized epigynum, internal structures shining through cuticle (fig. 277). Internal genitalia as in fig. 278.

DISTRIBUTION: Known only from type locality.

MATERIAL EXAMINED: BRAZIL: Espírito Santo: types above.

USNM

Smithsonian Institution, National Museum of Natural History

MCP

Pontificia Universidade Catolica do Rio Grande do Sul

AMNH

American Museum of Natural History

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Pholcidae

Genus

Metagonia

Loc

Metagonia beni

HUBER, BERNHARD A. 2000
2000
Loc

Anomalaia mariguitarensis González-Sponga, 1998: 25

Gonzalez-Sponga 1998: 25
1998
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