Tetragnatha vermiformis Emerton, 1884,

Castanheira, Pedro de Souza, Baptista, Renner Luiz Cerqueira, Pizzetti, Daniela Dos Passos & Teixeira, Renato Augusto, 2019, Contributions to the taxonomy of the long-jawed orb-weaving spider genus Tetragnatha (Araneae, Tetragnathidae) in the Neotropical region, with comments on the morphology of the chelicerae, Zoosystematics and Evolution 95 (2), pp. 465-505: 477-478

publication ID

http://dx.doi.org/10.3897/zse.95.36762

publication LSID

lsid:zoobank.org:pub:61A44D72-5E9B-40C6-9440-27E395110DE8

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http://treatment.plazi.org/id/1FA45899-071A-50D4-A8B7-05A3BC5578DF

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scientific name

Tetragnatha vermiformis Emerton, 1884
status

 

Tetragnatha vermiformis Emerton, 1884  Figs 17View Figure 17, 18View Figure 18, 19View Figure 19, 20FView Figure 20, 22FView Figure 22

Type material.

UNITED STATES OF AMERICA: ♂ lectotype, ♀ paralectotype ( Levi 1981). ♀ lectotype, 3♀ paralectotypes in MCZ database, Beverly, Essex, Massachusetts (Coll. J. H. Emerton, 15.xiii.18xx), not examined.

Extended diagnosis.

Males and females of T. vermiformis  are most similar to T. pallescens  F. O. Pickard-Cambridge, 1903. Males have similar length and width of chelicerae ( Figs 17 D–GView Figure 17, 19AView Figure 19, Banks 1892: 51, pl. 5, fig. 88 as T. pallida  ; Okuma 1992: 236, fig. 16 A–E); ‘T’ and ‘rsu’ very alike, sclerotized and pointed; Gl very sclerotized, thick and pointed, with a very large base, remaining teeth set apart by similar gaps. They also share similar elongated paracymbia, with finger-like notches and straight lateral knobs ( Figs 17JView Figure 17, 19EView Figure 19; Okuma 1992: 236, fig. 16D). The epiandrous field sets this species apart as it is flat and wide, with 20 fusules in two bands ( Fig. 19FView Figure 19).

Females of both species have similar small, rounded and laterally bulging chelicerae ( Figs 18 D–GView Figure 18, 19BView Figure 19; Okuma 1992: 236, fig. 16F, G); Gu isolated from U2; Gl from L2 by large gaps, with all teeth very pointed; and similar short genital folds ( Fig. 18HView Figure 18; Okuma 1992: 236, fig. 16J). Nonetheless, males and females of T. vermiformis  differ from T. pallescens  in having eyes much smaller and delicate and abdomen not as long and projecting ( Figs 17 A–CView Figure 17, 18 A–CView Figure 18; Okuma 1992: 236, fig. 16H, I). Males differ by the following characters: absence of ‘sl’ ( Figs 17 D–FView Figure 17, 19AView Figure 19); ‘a’ bending downward and closer to fang base ( Figs 17 D–GView Figure 17, 19AView Figure 19); Gu not so close to fang base, larger and with thicker base ( Figs 17D, EView Figure 17, 19AView Figure 19); Gu and ‘T’ placed apart from the row proper, towards lower side and following fang’s closing ( Figs 17D, EView Figure 17, 19AView Figure 19); Gl with wider basis and close to AXl and fang basis ( Figs 17E, FView Figure 17, 19AView Figure 19); presence of an inner cusp on fang ( Figs 17D, FView Figure 17, 19AView Figure 19) and more elongated conductors, with thicker projected tips completely enfolding the emboli, not ending in long tails ( Figs 17 H–JView Figure 17, 19C, DView Figure 19, 20FView Figure 20). Females differ in lacking both AXu and AXl and having smaller and triangular Gu, longer and wider U2, and lack of a small denticle and groove near the base of L2 ( Figs 18 D–FView Figure 18, 19BView Figure 19; Okuma 1992: 236, fig. 16G). Females of T. vermiformis  and T. pallescens  have similar internal genitalia, with two curved kidney-shaped spermathecae on edge of plate, lacking central membranous sacs ( Fig. 18IView Figure 18; Levi 1981: 311, fig. 131). However, T. vermiformis  has longer spermathecae, without a median membranous area ( Fig. 18IView Figure 18).

Variation.

Males (n = 4): total length, 6.29-7.29; females (n = 7): total length, 6.99-10.98. The spermathecal lobes are variable in size and form. Both lobes may be more regularly cylindrical and the external lobe may be much smaller than the inner one ( Levi 1981: figs 178-180) or both lobes may be curved and about the same size ( Fig. 18IView Figure 18; Zhu and Zhang 2011: fig. 133H).

Distribution.

Temperate and tropical Asia, North and Central America, newly recorded from South America (Brazil) ( Fig. 22FView Figure 22).