Tetragnatha laboriosa Hentz, 1850

de Souza Castanheira, Pedro & Baptista, Renner Luiz Cerqueira, 2021, Redescription of Tetragnatha guatemalensis, T. laboriosa and T. jaculator, with new synonymies of genus Tetragnatha (Araneae: Tetragnathidae) in the Neotropical Region, Journal of Natural History 54 (47 - 48), pp. 3031-3057 : 3040-3047

Tetragnatha laboriosa Hentz, 1850

( Figures 29–55 , 82 )

Type data

Tetragnatha laboriosa Hentz, 1850: 27 , pl. 4, fig. 3. (male syntype destroyed; male neotype designated by Levi (1981) from USA, Massachusetts, Middlesex, Holliston , in MCZ 21762, 23.VI.1929, not examined) .

Tetragnatha insulata Hogg, 1913: 41 , pl. 2, fig. 6 (males and females syntypes from Falkland Is., deposited in NHM 185–186, 01.III.1924, examined) syn. nov.

Tetragnatha bidens Mello-Leitão, 1943: 136 , figs 1–3 (male lectotype from Chile, Llanquihue , Maullin, deposited in MNRJ 2309 , examined) syn. nov.

Tetragnatha bidentata Roewer, 1951: 456 (replacement name for Tetragnatha bidens Mello-Leitão, 1943 , preoccupied by T. bidens F.O. Pickard-Cambridge, 1903 )

Diagnosis

The male chelicerae of T. laboriosa are morphologically similar to that of T. jaculator and T. elongata Walckenaer, 1841 . All three species share the following characters: absent AXu, very small or absent ‘t’, Gu present, protruding ‘sl’ slightly basalward projected, elongated and robust ‘T’ and long Gl much larger than other lower row teeth ( Figures 32–34 , 48–49 , 59–61 , 74–75 ; Okuma 1992, fig 6A, B; Castanheira et al. 2019, figs 5D–F, 7A). T. laboriosa and T. elongata differ from T. jaculator by longer ‘a’, absence of ‘t’, tegulum not slanted and conductor tip posteriorly directed, ending in a curved tail ( Figures 32–34, 36, 37 , 48, 52, 53 ; Castanheira et al. 2019, figs 5D, E, H–J, 7A, C–E, 20B). It is set apart from T. elongata by its shorter and thinner chelicerae (3.5x vs 4.4x longer than wide), ‘sl’ bulkier and ‘T’ less elongated and with a straight and narrower basis ( Figures 32, 33 , 48 ). The palps of T. laboriosa differ from T. elongata by its much narrower tibia (ca. 2x vs 5x longer than wide), elongated basally projected tail on conductor tip ( Figures 36, 37 , 52, 53 ) and paracymbium shorter, with a thin sclerotised base and globose knob ( Figures 38 , 54 ). Females are very similar to T. vermiformis . Both species share short, cylindrical abdomen; similar small, bulging paturon with large gap between Gu and U2; very short genital fold and small internal genitalia without CS ( Figures 39–47 ; Zhu and Zhang 2011, fig 133C–H; Castanheira et al. 2019, figs 18A–I, 19B). T. laboriosa differ by the chelicerae bearing both AXu and AXl; Gu closer to fang basis, distalward projected, with wider basis; Gl distalward projected, with wider basis, and internal genitalia with both pairs of spermathecae tubular, comma-like, clearly apart and ending in rounded and wider tips ( Figures 42–44, 47 , 50, 51 ).

Description

Male: Carapace light brown and elongated, with slightly elevated anterior part ( Figures 29, 30 ). Labium brown longer than wide ( Figure 31 ). Sternum light brown with dusky edges ( Figure 31 ). Eyes rows parallel and slightly procurved, ringed in black, AME and ALE set apart by twice its width, posterior row with eyes evenly separated, ALE and PLE almost touching ( Figure 29 ). Legs light brown and very elongated, without spines ( Figures 29–31 ). Chelicerae around 2.6x longer than wide and little over 2x shorter than carapace, moderately curved outwards, around 40° from body median line ( Figures 29, 32–35 , 48, 49 ), and with small carved apex; ‘a’ protruding, moderately thick, with less sclerotised base, projected distal- and outward, clearly bent from middle up to excavated tip and displaced a little outwards from the middle line of paturon ( Figures 32, 33, 38 ). AXu and ‘t’ absent ( Figures 32, 33 , 48 ). Upper row with seven uneven teeth ( Figures 32, 33 , 48 ): Gu with large base, small, slightly bent upward, and apart from ‘sl’ by large gap; ‘sl’ thick, triangular, pointed and basalward projected; ‘T’ long, thin, and almost straight, with slightly large base and ‘rsu’ with four teeth evenly decreasing in size, with U7 much smaller, almost a denticle. AXl small, thin and slightly pointed distal and downward, almost adjoined to fang basis ( Figures 33, 34 , 49 ). Lower row with five teeth ( Figures 33, 34 , 49 ): Gl thick, projected distalward and much longer than remaining teeth, L2–L5 triangular, almost straight and with almost same size, with L2 a bit more sclerotised than others. Cheliceral fang bent inward, uniformly thick throughout its length and abruptly tapering from its proximal end closing between both teeth rows ( Figures 32–34 , 48, 49 ). Abdomen cylindrical, almost 2x longer than carapace, dorsally pale beige, completely covered by guanine crystals, scantier at middle line ( Figures 29–31 ). Venter brown, with two guanine crystals line from base of book lungs towards spinnerets and a nude median portion ( Figure 31 ). Palps with short and triangular tibia (ca. 2x longer than wide), followed by small cymbium, bearing large basis, slight constriction at middle, and distal third thin and slightly curved prolaterally, ending in roundish point ( Figures 36–38 , 52 ); tegulum oval, more than two times wider than high ( Figures 36 , 52 ); conductor anteriorly thicker, with small projection over the tegulum, which is twisted and tapering near midway, medially enfolding over the embolus with its thin anterior edge and projected as small lateral bulge near apex ( Figures 36, 37 , 52, 53 ); embolus thick, very sclerotised, originated at middle portion of bulb, near cymbium, with long levelled curve at initial portion, followed by strong upward curve in prolateral view, then long, almost straight, and very larger median portion, and with curved elongated bird-head tip, with long basalward projected tail ( Figures 36, 37 , 52, 53 ); paracymbium short, approximately 2.5x longer than wide, not slanted, clearly excavated at the basis, with roundish notch, translucent lobe as longer as wide, occupying only a little part of ventral side, and large and sclerotised wide knob, with flat apex ( Figures 38 , 54 ).

Total length 5.37. Carapace 2.69 long, 1.23 wide. Abdomen 3.50 long, 1.30 wide. Left chelicera 1.46 long, 0.44 wide. Leg formula I–II–IV–III. Leg I: femur 5.00, patella 0.82, tibia 5.16, metatarsus 5.20 and tarsus 0.93. Leg II: patella + tibia 3.69. Leg III: patella + tibia 1.45. Leg IV: patella + tibia 2.98.

Female: Carapace colour, endites, fovea, eyes, labium, sternum and legs as in male ( Figures 39–41 ). Chelicerae with same colour as male, paturon around 2.4x longer than wide, 2x shorter than carapace and moderately curved outwards, around 40° from body median line, medially bulged on its upper side and straight on its lower side ( Figures 39, 42–45 , 50, 51 ). AXu rounded and very reduced ( Figures 42, 43 , 50 ). Upper row with six teeth ( Figures 42, 43 , 50 ): Gu very thick, projected distalward, with sclerotised tip and apart from U2 by a large gap, U3–U6 straight and decreasing in size. AXl extremely reduced to a small nub ( Figure 51 ). Lower row with six teeth ( Figures 43, 44 , 51 ): Gl short and thick projected distalward, apart from L2 by moderate gap, L2–L6 slightly pointing distalward, and barely decreasing in size, with L2 thicker than others and more distalward projected. Cheliceral fang thick and uniformly tapering to its tip ( Figures 42–44 , 50, 51 ). Abdomen as in male but slightly larger midway. ( Figures 39–41 ). Genital fold very short, 2.7x wider than long, almost in the same line as book-lungs, with straight tip ( Figure 46 ). Internal genitalia composed of two smalls tubular spermathecae, clearly separated, comma-like, with wide tips, located on wide uterus externus at each side of fold edges, without CS ( Figure 47 ).

Total length 7.81. Carapace 2.52 long, 1.48 wide. Abdomen 6.24 long, 2.48 wide. Left chelicera 1.11 long, 0.44 wide. Leg formula I–II–IV–III. Leg I: femur 5.30, patella 1.06, tibia 5.14, metatarsus 5.05 and tarsus 1.51. Leg II: patella + tibia 3.62. Leg III: patella + tibia 1.67. Leg IV: patella + tibia 3.54.

Variation

Males (n = 10): total length, 5.37–9.03; females (n = 16): total length, 7.81–11.46. Mello- Leitão’s type specimens and the male ones we examined from South America have slight differences in comparison to the specimens from the Caribbean ( Cuba and Dominican Republic), and illustrations of specimens from Central and North America (e.g. Levi 1981; Okuma 1992). The conductor of South American’s specimens have equal conformation, size and shape as specimens from Levi (1981, figs 6h, i, 19, 20, 127, 128) and Okuma (1992, fig. 11F), but have a thinner and more elongated basalward projected tail-like tip, differing from the shorter and so called ‘bird head tip’ from northern specimens. South American specimens are more similar to the type series of T. alba F. O. Pickard-Cambridge, 1903 , a junior synonym of T. laboriosa , from Mexico (see F. O. Pickard-Cambridge 1903, fig. 15, 15a). Also, some Argentine specimens we analysed (e.g. MACN 5266) have differences in cheliceral teeth conformation. They have L2 as the longest tooth in the ventral row, while the holotype of T. bidentata and Central and North American specimens have Gl instead. Notwithstanding those differences on palps and chelicerae, we consider that all of them represent the normal range of variation inside a species. So far, it is better to ascribe all of them to T. laboriosa , until additional specimens are analysed and the intraspecific variation may be better assessed, especially because Levi (1981) pointed out and illustrated a range of variation common within this species in the specimens from North America.

Synonymy and notes

Hentz (1850) described T. laboriosa based on a male from the United States ( USA), without precise location. Keyserling (1865) redescribed the male of this species and described for the first time its female, both from Baltimore/ USA. According to Levi (1981), all specimens from the USA were destroyed and he designated a neotype from Massachusetts deposited at MCZ. Furthermore, an extensive amount of papers acknowledged the presence of this species in North America: USA mainland (e.g. Emerton 1884, 1902; McCook 1894; Bryant 1908; Seeley 1928; Kaston 1948), Alaska (e.g. Banks 1900; Seeley 1928; Levi 1981) and Canada (e.g. Emerton 1919; Seeley 1928; Dondale et al. 2003; Paquin and Dupérré 2003).The species was also recorded from different localities in Central America: Mexico ( Seeley 1928; Levi 1981; Okuma 1992); Puerto Rico ( Banks 1901; Petrunkevitch 1930); Guatemala ( Okuma 1992); Costa Rica ( Okuma 1992) and Panama ( Seeley 1928; Chickering 1957c). Furthermore, Levi (1981) pointed out that this species is very common in North America and Okuma (1992) stated that T. laboriosa is probably one of the most common species of the genus in the continent, alongside T. elongata .

Tetragnatha insulata Hogg, 1932 was described from the Falkland Islands, based on a female and a male syntypes. On its original description, Hogg mainly focused on the female, which was first described and has its body and appendage reasonably described and measured, with the male being poorly described. The first author of this paper was able to analyse the type material of this species, observing the teeth conformation of the chelicerae of both sexes and male genitalia, acknowledging Hogg’s description. Males bear the long-tailed embolus tip and the small basalward projected ‘sl’ before the elongated ‘T’, while the females bear small chelicerae, with laterally bulged paturon without AXu or AXl and Gu–U2 and Gl–L2 as the largest teeth. Therefore, after comparing the syntypes of T. insulata , with excellent illustrations of the neotype by Levi (1981) and a fair number of specimens for South America, we can confirm T. insulata = T. laboriosa syn. nov.

Additionally, Mello-Leitão (1943) described T. bidens based on a male from Maullin, Chilean Patagonia. The holotype of this species is deposited at Museu Nacional/ Universidade Federal do Rio de Janeiro (MNRJ 2309) and was saved from the tragic 2018 fire. Even though Mello-Leitão only mentions the more elongated ‘T’ on the description of this species, a curved and basalward projected ‘sl’ on the upper row of the chelicera is visible on his drawings (see Mello-Leitão 1943, p. 138, fig. 1). About the genitalia, he limited his description to a ‘complex bulb’, but his drawings also confirm the typical elongated tail of the conductor and embolus tips.

Habitat notes

According to information provided in many papers (e.g. Kaston 1948; Levi 1981; Dondale et al. 2003), this species is not associated to water bodies and build horizontal orb webs near the ground in open areas, above dry grass or crop fields. However, no specimens of this species were collected by the authors of the present study.

Distribution

From Alaska to Brazil, South of Argentina and Maullin, Chilean Patagonia ( Figure 82 ).

Material examined

CUBA, Santiago de Cuba: Siboney, Reserva Ecológica Siboney-Jutici (19.9592661, −75.7077581), ♂, 16 .V .2001, G . Garces leg . ( IBSP 169938 ); La Redonda, Carretera Siboney (20.0141657, −75.7754266), ♂, ♀, 08 .XII .1999, J . L . Reyes leg . ( IBSP 169939 ) . DOMINICAN REPUBLIC, Azua: Pueblo Viejo, Casa 2 (18.4, −70.766667), ♂, ♀, 21 .VI .2004, A . Sánchez leg . ( IBSP 169944 ) . BRAZIL, Sergipe: Santo Amaro das Brotas (−10.788889, −37.053889), ♂, 3j, 08 .X .1978, MSS Carvalho leg . ( MZUSP 10556 ) ; São Paulo: Itú, Fazenda Pau D’Alho (−23.263889, −47.298889), ♂, 17–18 .IX .1960, P . Biasi leg . ( MZUSP 14755 ) ; Rio Grande do Sul: Santa Maria (−29.683889, −53.806944), ♂, ♀, 2j, 30 .I .1990, D . Linck leg . ( MCTP 43317 ex 5972); São Leopoldo (−29.76, −51.146944), 1 ♀, VI .1965, C . Valle leg . ( MZUSP 4430 ); Santo Ângelo , Cristo Rei (−28.1694424, −54.3902876), ♀, 21 .X .1967, P . Biasi leg . ( MZUSP 7185 ); São Francisco de Paula , Potreiro Velho (−29.447778, −50.583889), ♂, 20 .I .1994, A . A . Lise leg . ( MCTP 4513 ); Guaíba (−30.113889, −51.325), 2 ♂, III .1984, A . A . Lise leg . ( MCTP 43316 ex 12770) . CHILE, no additional data, 6♂, 2♀ ( MNHN 12628 ); Valparaiso: Valparaíso (−33.0459502, −71.6307079), ♂, X .1970, M . Fritz leg . ( MACN 39802 ex 24656) . PARAGUAY, Misiones: Yacyretá Island (−26.633333, −57.166667), ♀, X .1975, A . Martínez leg . ( MACN 24431 ) . ARGENTINA, Corrientes: Manantiales (−27.9249206, −58.1102847), 13♂, 26♀, 3j, IX .1960, Apóstol leg . ( MACN 5266 ); Neuquén: (−38.966667, −68.066667), 3♂, ♀, III .1942, Lieberman leg . ( MACN 1184 ); Estancia San Ramon, Ramon Chico, R . Liniz (−38.7907243, −68.4429479), 3♂, 3♀, 3j, I . 1962, Hamylenko leg . ( MACN 24563 ); Neuquén , Lago Hermoso (−38.94367, −68.0929512), 2♂, ♀, 15 .I .1985, M . Ramírez leg . ( MACN 24651 ); Río Negro: El Bolsón, Región Patagonica (−41.966667, −71.533333), 2♂, 3j, XI .1962, M . Birabén leg . ( MACN 24473 ); Santa Cruz: (−49.1071416, −74.1425266), ♀ ( MACN 3140 ) .

Figures

Figure 82. New records of T. guatemalensis, T. laboriosa and T. jaculator in the Neotropical Region.

Figures 29–38. Tetragnatha laboriosa male (MACN 24651): 29, dorsal habitus; 30, lateral habitus; 31, ventral habitus; 32, left chelicera, upper view; 33, left chelicera, inner view; 34, left chelicera, lower view; 35, left chelicera, outer view; 36, left palp, mesal view; 37, left palp, dorsal view; 38, left palp, ventral view (paracymbium). Scale bars: Figures 29–31, 2 mm; Figures 32–38, 0.5 mm.

Figures 39–47. Tetragnatha laboriosa female: 39, dorsal habitus (MACN 24563); 40, lateral habitus (MACN 24563); 41, ventral habitus (MACN 24563); 42, left chelicera, upper view (MACN 24651); 43, left chelicera, inner view (MACN 24651); 44, left chelicera, lower view (MACN 24651); 45, left chelicera, outer view (MACN 24651); 46, genital fold, ventral view (MACN 24651); 47, internal genitalia, ventral view (MZUSP 4430). Scale bars: Figures 39–41, 2 mm; Figures 42–46, 0.5 mm; Figure 47, 0.2 mm.

Figures 48–55. Tetragnatha laboriosa SEM photos, male: 48, left chelicera, upper view (MACN 24651); 49, left chelicera lower view (MACN 1184); 52, left palp, mesal view (MACN 24651); 53, conductor and embolus opening, mesal view (MACN 24651); 54, paracymbium, ventral view (MACN 24651); 55, epiandrous, ventral view (MACN 1184). Female: 50, left chelicera, upper view (MACN 24651); 51, left chelicera, lower view (MACN 1184). Scale bars: Figures 48–51, 0.2 mm; Figure 52, 0.1 mm; Figures 53, 55, 0.02 mm; Figure 54, 0.05 mm.

Figures 56–65. Tetragnatha jaculator male (UFRJ 1621): 56, dorsal habitus; 57, lateral habitus; 58, ventral habitus; 59, left chelicera, upper view; 60, left chelicera, inner view; 61, left chelicera, lower view; 62, left chelicera, outer view; 63, left palp, mesal view; 64, left palp, dorsal view; 65, left palp, ventral view (paracymbium). Scale bars: Figures 56–58, 2 mm; Figures 59–65, 0.5 mm.

Figures 74–81. Tetragnatha jaculator SEM photos, male: 74, left chelicera, upper view (MCTP 43314 ex 5987); 75, left chelicera lower view (MCTP 7887); 78, left palp, mesal view (MCTP 7887); 79, conductor detail, mesal view (MCTP 7887); 80, paracymbium, ventral view (MCTP 7887); 81, epiandrous, ventral view (MCTP 7887). Female (MCTP 7887): 76, left chelicera, upper view; 77, left chelicera, lower view. Scale bars: Figures 74–77, 79, 80, 0.2 mm; Figure 78, 0.5 mm; Figure 81, 0.05 mm.