Glenognatha Simon, 1887,

Jimmy Cabra-García & Antonio D. Brescovit, 2016, Revision and phylogenetic analysis of the orb-weaving spider genus Glenognatha Simon, 1887 (Araneae, Tetragnathidae), Zootaxa 4069 (1), pp. 1-183: 16-19

publication ID

http://doi.org/10.11646/zootaxa.4069.1.1

publication LSID

lsid:zoobank.org:pub:52FC658C-78C7-49FC-9961-8AC43CA03101

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http://treatment.plazi.org/id/8E0E8F67-7D1D-FF9A-ACBA-0DA0FAA8D7AA

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scientific name

Glenognatha Simon, 1887
status

 

Glenognatha Simon, 1887 

Glenognatha Simon, 1887: 193  , type species by monotypy Glenognatha emertoni Simon, 1887  . Mimognatha, Banks, 1929: 90  , type species by monotypy Mimognatha foxi Banks, 1929  . Synonymized by Levi, 1980: 64. Hivaoa, Berland, 1935: 50  , type species by original designation Hivaoa argenteoguttata Berland, 1935  . Synonymized by Levi,

1980: 64.

Diagnosis: Males of Glenognatha  resemble those of Pachygnatha  by the presence of a retrolateral apophysis on the conductor ( Fig. 74GView FIGURE 74). It can be distinguished from the latter genus by the paracymbium with the distal portion oriented in opposite direction to the cymbium as seen in retrolateral view ( Figs. 11HView FIGURE 11, 16HView FIGURE 16, 23HView FIGURE 23, 27HView FIGURE 27, 28GView FIGURE 28, 40HView FIGURE 40, 47HView FIGURE 47, 49BView FIGURE 49, 70JView FIGURE 70, 91HView FIGURE 91, 99HView FIGURE 99, 128HView FIGURE 128), the folded retrolateral apophysis on the conductor lamina ( Figs. 18BView FIGURE 18, 23F, LView FIGURE 23, 28FView FIGURE 28, 54CView FIGURE 54, 79CView FIGURE 79, 84EView FIGURE 84, 92GView FIGURE 92) and the embolus with a medial groove in its basal portion ( Figs. 18BView FIGURE 18, 23OView FIGURE 23, 43DView FIGURE 43, 47HView FIGURE 47, 49F –GView FIGURE 49, 54 AView FIGURE 54, 58HView FIGURE 58, 125IView FIGURE 125). Females can be diagnosed by an anteriorly displaced tracheal spiracle ( Figs. 9GView FIGURE 9, 14GView FIGURE 14, 30 AView FIGURE 30, 31GView FIGURE 31, 50GView FIGURE 50, 60CView FIGURE 60, 80GView FIGURE 80, 126CView FIGURE 126) and a tracheal system composed of two median trunks divided into numerous distal and lateral tracheoles flanked by two unbranched lateral tracheae ( Figs. 12C –FView FIGURE 12, 18E –GView FIGURE 18, 24 AView FIGURE 24, 41D –FView FIGURE 41, 48G –JView FIGURE 48, 49H –JView FIGURE 49, 74I –JView FIGURE 74, 92J –LView FIGURE 92, 103F –HView FIGURE 103, 121D –GView FIGURE 121). As currently delimited, the genus Dyschiriognatha  also shares these diagnostic features. Nevertheless, its synonymy with Glenognatha  cannot be objectively proposed (see ‘Discussion’ section).

Description: Total length 1.25–4.60 males, 1.40–4.80 females. Carapace longer than wide, 0.62–2.4 long in males and 0.61–2.05 long in females; pale yellow to dark brown ( Figs. 14 AView FIGURE 14, 19 AView FIGURE 19, 38 AView FIGURE 38, 45 AView FIGURE 45, 75 AView FIGURE 75). Sternum as wide as long and prolonged between coxae in some species ( Figs. 25CView FIGURE 25, 31CView FIGURE 31, 50CView FIGURE 50, 56CView FIGURE 56, 60CView FIGURE 60). Labium trapezoidal, wider than long, and rebordered. Eyes subequal in size, lateral eyes slightly smaller. Clypeus height 1.10—3.21. Chelicerae large, sexually dimorphic, with 3–5 promarginal teeth and 3–10 retromarginal teeth ( Figs. 20View FIGURE 20, 46View FIGURE 46, 51View FIGURE 51, 57View FIGURE 57, 81View FIGURE 81, 86, 101, 115, 127). Cheliceral teeth numbers vary widely particularly on the retromargin, with some specimens presenting asymmetric teeth counts. Cheliceral boss well developed. Cheliceral fangs long and in some species with a well-developed retrolateral outgrowth ( Figs. 39 AView FIGURE 39, 46 AView FIGURE 46, 51 AView FIGURE 51, 68BView FIGURE 68, 90EView FIGURE 90). Legs without spines (except in G. hirsutissima  ), slightly longer in males than in females. Femur I length varies from 0.75 to 3.45 in males and from 0.67 to 3.4 in females. Leg formula I>II>IV>III. Femora dorsal surface with one to six trichobothria ( Figs. 30GView FIGURE 30, 44 AView FIGURE 44). Glenognatha foxi  , G. heleios  , G. iviei  and G. spherella  lack trichobothria on femur III and IV. Tibia dorsal surface with four to ten trichobothria ( Figs. 30HView FIGURE 30, 44EView FIGURE 44). Metatarsi I, II and III, first half, with one trichobothrium longer than the diameter of the article (two in G. hirsutissima  ). Metatarsus IV without trichobothria except in G. florezi  (one trichobothrium), G. camisea  (one), G. gouldi  (one), G. emertoni  (one) and G. hirsutissima  (two).

Abdomen oval to spherical. Dorsal pattern usually with disperse silver guanine patches combined with irregular dark longitudinal bands. Lateral surface also covered with a similar pattern of guanine deposits and dark bands. Ventral surface usually with a pale black median band and irregular silver guanine patches. Posterior tracheal spiracle wider than long and anteriorly displaced. Tracheal spiracle glands occupying both sides of the atrium and the basal region of the median trunks ( Figs. 12FView FIGURE 12, 24DView FIGURE 24, 41FView FIGURE 41, 48JView FIGURE 48, 83EView FIGURE 83, 92LView FIGURE 92, 103HView FIGURE 103, 129IView FIGURE 129). ALS with more than 12 piriform spigots ( Figs. 17FView FIGURE 17, 24FView FIGURE 24, 30DView FIGURE 30, 55DView FIGURE 55, 63EView FIGURE 63, 64FView FIGURE 64, 103IView FIGURE 103, 121HView FIGURE 121). PMS with one to five aciniform spigot between the cylindrical and the minor ampullate spigot ( Figs. 13DView FIGURE 13, 17GView FIGURE 17, 24GView FIGURE 24, 30EView FIGURE 30, 55EView FIGURE 55, 103JView FIGURE 103, 121IView FIGURE 121), nubbin posterior to the mAP. PLS with 4 to 25 AC spigots on both sexes ( Figs. 13EView FIGURE 13, 17HView FIGURE 17, 24HView FIGURE 24, 30FView FIGURE 30, 49LView FIGURE 49, 63GView FIGURE 63, 103KView FIGURE 103, 121JView FIGURE 121). Females AG –FL triplet anterior to the AC spigots and almost parallel with the anterior CY spigot ( Figs. 24HView FIGURE 24, 53IView FIGURE 53, 63GView FIGURE 63, 103KView FIGURE 103, 121JView FIGURE 121, 129LView FIGURE 129), except in G. florezi  that lacks the triplet ( Fig. 17HView FIGURE 17). PLS triplet also present in adult males ( Figs. 30FView FIGURE 30, 49LView FIGURE 49, 55FView FIGURE 55, 64HView FIGURE 64, 104LView FIGURE 104), except in G. boraceia  , G. lacteovittata  and G. florezi  ( Figs. 13EView FIGURE 13, 24KView FIGURE 24). Epiandrous fusules usually four, arranged in a transverse line ( Figs. 30CView FIGURE 30, 43BView FIGURE 43, 49MView FIGURE 49, 55BView FIGURE 55, 64DView FIGURE 64, 79DView FIGURE 79, 104HView FIGURE 104), although some species have up to eleven fusules such as in G. florezi  ( Fig. 18HView FIGURE 18).

Male palpal tibia as long as wide ( Figs. 91 AView FIGURE 91, 95 AView FIGURE 95, 107 AView FIGURE 107, 112 AView FIGURE 112) or longer ( Figs. 47 AView FIGURE 47, 52 AView FIGURE 52, 58 AView FIGURE 58, 62 AView FIGURE 62), with three to six trichobothria on its ventral and retrolateral surfaces. Cymbium elongated with a swollen apical portion and a conspicuous tarsal organ ( Figs. 18 AView FIGURE 18, 22EView FIGURE 22, 27EView FIGURE 27, 28FView FIGURE 28, 47EView FIGURE 47, 70KView FIGURE 70, 79CView FIGURE 79, 104 AView FIGURE 104). Paracymbium with two perpendicular portions, as seen in retrolateral view ( Figs. 11HView FIGURE 11, 27HView FIGURE 27, 47HView FIGURE 47, 49BView FIGURE 49, 99HView FIGURE 99, 128HView FIGURE 128). Tegulum spherical, with a distal depression where the embolus and the conductor rest. Embolus surrounding the conductor base. Embolic medial groove limited to the inner surface of the embolus ( Figs. 13 AView FIGURE 13, 18 AView FIGURE 18, 23DView FIGURE 23) or extended towards its outer surface ( Figs. 28HView FIGURE 28, 49FView FIGURE 49, 54 AView FIGURE 54, 64BView FIGURE 64, 74FView FIGURE 74, 92FView FIGURE 92, 97 AView FIGURE 97, 109 AView FIGURE 109). Embolus surface smooth or with filiform ( Fig. 23G, N, PView FIGURE 23), tooth-like ( Fig. 16DView FIGURE 16, 23PView FIGURE 23) or scale-like projections ( Fig. 54LView FIGURE 54). Conductor emerging from the center of the tegulum as a cylindrical tube that bends towards the center of the tegulum and flattens into a lamina. The conductor lamina has its apical portion folded and carries a conspicuous prolaterally folded retrolateral apophysis ( Figs. 18BView FIGURE 18, 23F, LView FIGURE 23, 28FView FIGURE 28, 54CView FIGURE 54, 79CView FIGURE 79, 84EView FIGURE 84, 92GView FIGURE 92). Embolus partially enclosed by the apical fold of the conductor lamina and the prolaterally folded retrolateral apophysis ( Figs. 18BView FIGURE 18, 23FView FIGURE 23, 28FView FIGURE 28, 43HView FIGURE 43, 70HView FIGURE 70, 79CView FIGURE 79, 97DView FIGURE 97). Female external genitalia slit-shaped with sclerotized edges. Internal genitalia haplogyne, with the following structures: a membranous chamber, a large uterus externus and a pair of copulatory ducts leading to the spermathecae ( Figs. 12 A –BView FIGURE 12, 17 A –EView FIGURE 17, 23 A –CView FIGURE 23, 28 A –CView FIGURE 28, 53 A –EView FIGURE 53, 70 A –EView FIGURE 70, 92 A –EView FIGURE 92, 129 A –CView FIGURE 129). The membranous chamber has filiform projections on its lateral borders that serve as muscle attachment points ( Figs. 48DView FIGURE 48, 53EView FIGURE 53). In some species the spermathecae and copulatory ducts are absent ( Figs. 12 A –BView FIGURE 12, 17 A –EView FIGURE 17, 53B –EView FIGURE 53, 121 A –CView FIGURE 121) (see also Cabra-García et al. 2014).

Composition: Glenognatha  currently includes 27 species: G. argyrostilba ( Pickard-Cambridge, 1876)  n. comb. G. australis ( Keyserling, 1883)  , G. dentata ( Zhu & Wen, 1978)  n. comb., G. emertoni Simon, 1887  , G. foxi ( McCook, 1894)  , G. gaujoni Simon, 1895  , G. globosa (Petrunkevitch, 1925)  , G. gloriae ( Petrunkevitch, 1930)  , G. heleios Hormiga, 1990  , G. hirsutissima ( Berland, 1935)  , G. iviei Levi, 1980  , G. lacteovittata ( Mello-Leitão, 1944)  , G. minuta Banks, 1898  , G. smilodon Bosmans & Bosselaers, 1994  , G. spherella Chamberlin & Ivie, 1936  , G. tangi ( Zhu, Song & Zhang, 2003)  n. comb. and 11 new species described herein.

Distribution: Glenognatha  species have a broad distribution with records in Nearctic, Neotropic, Afrotropic, Indo-Malaya, Oceania and Paleartic regions. It occupies a broad altitudinal range from 6 ( G. iviei  ) to 2,700 m. ( G. florezi  ) ( Figs. 130–138View FIGURE 130View FIGURE 131View FIGURE 132View FIGURE 133).

Natural history: The biology of Glenognatha  species is still poorly known and published data focus mainly on Nearctic species. Glenognatha foxi  is recorded as an abundant spider in a wide variety of crops in the United States: soybean ( Young & Edwards 1990; Balfour & Rypstra 1998), alfalfa ( Young & Edwards 1990; Birkhofer et al. 2007, Welch et al. 2011), rice, sugarcane, peanuts, cotton ( Agnew et al. 1985; Heiss & Meisch 1985; Young & Edwards 1990) and citrus ( Mansour et al. 1982). Chapman et al. (2013) recorded Collembola, Aphididae  and Brachycera as prey taxa for G. foxi  in winter wheat. Phenology of G. foxi  in Georgia was assessed by Draney (1997), who suggested a possible annual reproductive cycle with mating in the early summer. G. foxi  is recorded as the most abundant aerial species in one of the two sampling stations assessed by Dean & Sterling (1985). Barrows (1919) described some aspects of the reproductive biology and habits of G. foxi  . According to this author, G. foxi  is common in meadows and waste-lands in hot dry situations. The mating occurs in the middle of the web with cheliceral clasp and each male palp is inserted alternately every five minutes. The overall copula lasts fifteen minutes. Nevertheless, as noted by Heiss & Meisch (1985), G. foxi  also lives in moist conditions; populations in Arkansas rice crops build webs near the middle of the rice plants not far above the water.

Hormiga & Döbel (1990) and Döbel et al. (1990) provided phenology and web architecture data for G. heleios  . According with these authors, G. heleios  is a univoltine species in intertidal salt marshes of New Jersey, with greater abundance in short and intermediate forms of Spartina alterniflora  . Webs are placed close to the soil surface with the sticky spiral very closely spaced. Some aspects of the reproductive biology of G. heleios  were described by Edwards & Senske (2001). These authors recorded the insertion of only one palp and a copula duration of two hours.

Danielson-François (2006) carried on a detailed study of habits, sperm release patterns and reproductive behavior of G. emertoni  . In this work, specimens were found in vegetation overhanging streams and under streamside rocks in Arizona. Avoidance behavior after disturbance and mating behavior were described. In the former, the spider dropped into the water beneath and floated for some distance until the extended legs allow climbed up some streamside vegetation. The mating behavior involved cheliceral clasp, vibratory courtship through legs movements and palps insertions.

Glenognatha lacteovittata  is recorded as a common species in alfalfa and wheat crops in Argentina ( Armendano & González 2010, 2011). G. argyrostilba  is collected preferentially in humid habitats of Santa Cruz island in Galápagos, Ecuador ( Baert et al. 1991). Glenognatha dentata  is recorded in rice crops from China ( Barrion et al. 2012), India (Sebastian et al. 2005; Sudhikumar et al. 2005) and Philippines ( Barrion & Litsinger 1995; Litsinger et al. 2006). Dupo & Barrion (2009) classify G. dentata  as a specialist predator of planthoppers nymphs in rice Asian ecosystems.

Adults and juveniles of G. mendezi  were collected in low mountain humid forests in western Colombian Andes ( Figs. 7 A –BView FIGURE 7). This species builds its webs in vegetation adjacent to streams about 25 cm to 2 m above ground level, although some individuals were found far away from any current in low vegetation. In both cases, the web is almost horizontal. It has closed hub and few sticky spiral turns and radii ( Fig. 8CView FIGURE 8). The web frame can be rectangular or triangular. Some webs were observed under leaves.

Glenognatha patriceae  lives in the same habitats as G. mendezi  ( Fig. 7BView FIGURE 7). Nevertheless, this species builds its webs a few centimeters (1–5 cm) above streams ( Fig. 8DView FIGURE 8). Rocks are used as attachment points ( Fig. 8DView FIGURE 8). Web aggregations with shared radii and numerous hubs were commonly observed ( Fig. 8EView FIGURE 8). In this structures different individuals cohabit, each occupying one hub. No aggression between conspecifics was recorded. A similar avoidance behavior, as that described for G. emertoni  by Danielson-François (2006), was observed after disturbance. Diptera and Ephemeroptera were preyed during observations.

Glenognatha gaujoni  ( Figs. 8 A –BView FIGURE 8) builds its webs a few centimeters (1–7cm) above streams in Amazonian rainforests ( Figs. 7C –DView FIGURE 7). The web is horizontal with closed hub, few radii and sticky spiral turns ( Fig. 8FView FIGURE 8). 

Eberhard (1982) described the web building behavior of G. globosa  from Colombia (the identification of the voucher was made after Eberhard’s original publication). This species determines the sticky spiral attachment point tapping forward with the internal leg I, holds the next radius near the attachment point with the outer leg III and IV, pushes the current segment with internal leg IV, has no temporary spiral, attaches the sticky spiral to each radius crossed, lays one radius to the frame and lefts the hub of the web intact after finishing the sticky spiral.

PMS

Prirodonamen Muzej Skopje

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Tetragnathidae

Loc

Glenognatha Simon, 1887

Jimmy Cabra-García & Antonio D. Brescovit 2016
2016
Loc

Glenognatha

Levi 1980: 64
Berland 1935: 50
Banks 1929: 90
Simon 1887: 193
1887