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Before constructing an orb web, an araneoid spider takes down and ingests the previous day's web. Nocturnal species do this either during the early evening or in the early morning and diurnal species during the early morning, times of the day when relative humidity (RH) is high. Under these conditions the hygroscopic glue droplets of a web's viscous prey capture thread attract atmospheric moisture, providing a net gain of water when a spider ingests its web. The contribution of web recycling to a spider's water budget has been estimated, but not determined empirically. This study does so for adult females of four species (Araneus marmoreus Clerck, 1757, Argiope trifasciata (Forskal, 1775), Leucauge venusta (Walckenaer, 1841), and Micrathena gracilis (Walckenaer, 1805)) by first determining the total volume of a web's glue droplets at 20% and 37% RH to estimate the water invested in web during construction. Subtracting each of these values from the web's total droplet volume at 90% RH approximates the range of water harvested when the web is recycled. High estimates of the net water gained range from 0.45% of a spider's body mass (3.01 µl water gained) in A. marmoreus to 0.88% of body mass (0.19 µl water gained) in L. venusta. In A. trifasciata, the water gained when a web is ingested is equivalent to 29% of a spider's daily evaporative water loss.

Spiders are important arthropods in agroecosystems, as they serve as indicators of environmental quality, in addition to the role that they can play as biological control agents of some pest species in crops. On the other hand, shrub species such as Salvia rosmarinus (L.), commonly known as rosemary, are often used as live fences, being near to important crops such as onion, potato, lettuce, among others. Cerro Punta is the main producing area of ​​these products in the country. The objective of this study was to know the community of spiders associated with rosemary in Cerro Punta, Chiriquí, Panama. For this, random samplings were carried out in rosemary plants, located in different sites of Cerro Punta. The spiders were observed, photographed, collected and identified, with the support of specialized literature. According to the results, 57% of the spiders corresponded to the species Argiope argentata (Fabricius, 1775), 36% were individuals of Leucauge venusta (Walkenaer, 1841) and 7% corresponded to a species of the genus Nephila. Additionally, adult specimens from the Suborder Homoptera were found trapped in the cobwebs. In conclusion, the community of spiders associated with rosemary in Cerro Punta is represented by at least three genera, which can contribute to the natural balance of the entomofauna in the agroecosystem. Las arañas son artrópodos de importancia en los agroecosistemas, por servir como indicadores de la calidad ambiental, además del rol que pueden desempeñar como agentes de control biológico de algunas especies de insectos plaga en plantas de interés. Adicionalmente, especies arbustivas como Salvia rosmarinus (L.), comúnmente conocida como romero, suelen ser utilizadas como cercas vivas, encontrándose colindantes con cultivos de importancia como las hortalizas; siendo Cerro Punta la principal zona productora de dichos rubros en el país. El objetivo del presente estudio consistió en conocer la comunidad de arañas asociadas al romero en Cerro Punta, Chiriquí, Panamá. Para ello, se realizaron muestreos aleatorios en plantas de romero, situadas en diferentes sitios de Cerro Punta. Las arañas fueron observadas, fotografiadas, colectadas e identificadas, con apoyo de literatura especializada. Los resultados obtenidos indicaron que, el 57% de las arañas encontradas correspondió a la especie Argiope argentata (Fabricius, 1775), 36% fueron individuos de Leucauge venusta (Walkenaer, 1841) y 7% correspondió a una especie del género Nephila. Adicionalmente, se observó en las telarañas de especímenes adultos capturados del Suborden Homoptera. Se concluye que, la comunidad de arañas asociadas al romero en Cerro Punta, está representada por al menos tres géneros de arañas, las cuales pueden contribuir con el balance natural de la entomofauna asociada al agroecosistema.

The orchard spider, Leucauge venusta (Walckenaer, 1841) is one of the most common and abundant orb-weavers in North America. This species has a broad geographic distribution extending across tropical and temperate regions of the Americas from Canada to Brazil. Guided by a preliminary observation of the barcode gap between sequences from specimens of L. venusta collected in Florida and other North American localities, we collected across a transect through the southeastern USA to investigate the observed genetic divide. The dataset, complemented with additional samples from Mexico, and Brazil was analyzed for species delimitation using STACEY and bGMYC based on sequences from one nuclear (ITS2) and one mitochondrial marker (COI). The analyses clearly separate USA samples into two deeply divergent and geographically structured groups (north–south) which we interpret as two different species. We generated ecological niche models for these two groups rejecting a niche equivalence hypothesis for these lineages. Taxonomic changes are proposed based on these findings, Leucauge venusta is restricted to denote the northern clade, and its known distribution restricted to the USA. Leucauge argyrobapta (White, 1841) is removed from synonymy to denote the populations in Florida, Mexico and Brazil. Although the delimitation analyses suggest each of these geographic clusters within the L. argyrobapta samples represent different species, more specimens from Central and South America are needed to properly test the cohesion of L. argyrobapta populations.

The orchard orbweavers, Leucauge argyrobapta (White) (Figure 1) and Leucauge venusta (Walckenaer), are attractive small spiders and collectively are some of the most common spiders in the eastern U.S. The name orchard orbweaver is the common name accepted by the American Arachnological Society Committee on Common Names of Arachnids (Breen 2003) for these species, but they have also been called simply orchard spiders (Kaston & Kaston 1953, Levi & Levi 2002). Orchard orbweavers belong to the family Tetragnathidae, the longjawed orbweavers (Levi & Hormiga 2017, World Spider Catalog 2018). This document describes its synonymy and nomenclature, distribution, description, behavior, and enemies. Also available on the Featured Creatures website at http://entomology.ifas.ufl.edu/creatures. https://edis.ifas.ufl.edu/in1243

Four predatory spider species, Leucauge venusta (Orchard) (Araneae: Tetragnathidae), Lycosa pseudoannulata (Boeset) (Araneae: Lycosidae), Larinioides cornutus (Clerck) (Araneae: Araneidae), and Tetragnatha shikokiana (Yaginuma) (Araneae: Tetragnathidae), were used to control Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in the laboratory and greenhouse, and their longevity without food was observed. For the laboratory experiment, the spiders' feeding capabilities were checked at 1, 4, 8, and 16 h of exposure in a 10 mL vial containing 50 five-d-old whiteflies. For the greenhouse experiment, the preys' feeding ability was recorded at 24 and 48 h, with 100 five-d-old adult whiteflies in a screened cage. Individual spiders were kept in the lab in 10 mL vials, and their survival time was recorded every 5 h. Of the 4 spider species, L. pseudoannulata was the most active in the lab and consumed an average of 3.00 ± 0.22, 6.17 ± 0.27, 9.67 ± 0.43, and 13.50 ± 0.49 at 1, 4, 8, and 16 h of the bioassay, followed by L. venusta, L. cornutus, and T. shikokiana. However, in the greenhouse experiment, L. venusta consumed the greatest number of whiteflies, with an average of 24.66 and 51.33 (out of 100) at 24 and 48 h, respectively, followed by L. pseudoannulata, L. cornutus, and T. shikokiana. The maximum longevity was recorded for L. venusta with 26.67 h, followed by T. shikokiana, L. pseudoannulata, and L. cornutus without prey. All spider species killed and consumed adult whiteflies in both experiments, which suggests that they are a controlling tool in the natural ecosystem. The results from our experiment will contribute to the biological control of whitefly.

Tephritid pests controlled through the sterile insect technique (SIT) are mass-reared and subsequently released in affected areas. Several quality parameters are currently used to test adults, but none take into account interactions with a predator. When sterile males are released in the field, they will need to avoid predators until they reach sexual maturity and survive long enough to mate with wild females. Spiders are one of the most common predators that flies may encounter in release sites. In this study, we evaluated the antipredator behavior of a mass-reared sterile unisexual strain (‘Tapachula-7’) of the Mexican fruit fly Anastrepha ludens (Diptera: Tephritidae) against their spider predators. We sampled spiders in citrus trees to determine which families could be more common. We established the baseline activity rates of sterile Tapachula-7 (Tap-7) flies in comparison with wild flies. We also tested the behavior of the fertile and sterile bisexual strain and wild flies against hunting spiders (Family Salticidae) and orb building spiders (Family Tetragnathidae). We recorded 18 spider families, with Salticidae being the most dominant. Tap-7 flies diminished their activity in comparison with wild males at 1800 h but showed similar activity levels earlier in the day. When exposed to orb-web spiders (Leucauge venusta), Tap-7, fertile and sterile males from the bisexual strain had similar rates of survival, but Tap-7 males showed lower survival than wild males. Against hunting spiders (Phidippus audax), wild males had higher probability of defensive wing displays, but there was no difference in spider attack rates. In general, sterile Tap -7 males performed as well as males from the bisexual strain, although they had lower survival than wild males. This could be due to either mass-rearing and/or irradiation effects. We recommend the use of the defensive wing display behavior as a quality parameter and propose a rapid and effective method to evaluate fly activity. The efficiency of SIT will be improved if released sterile males have the same antipredator repertoire as their wild counterparts.

This study describes a case of interspecific aggregation involving a spider's web and its effect on web architecture of another species of spider. On two transects of 100 m each, one with Nephila clavipes (Linnaeus 1767) webs and one without, we noted the spiders associated, or not, with N. clavipes webs, and compared the web architecture of the most commonly associated species, Leucauge venusta (Walckenaer 1842). The transect with N. clavipes contained more spiders in general than that without N. clavipes, most of which were L. venusta for both transects. The height above ground of L. venusta webs associated with N. clavipes presented a larger range of distribution, which closely mimicked that of N. clavipes webs except when the N. clavipes web was at ground level. Leucauge venusta webs were more inclined when in association with N. clavipes (49.4 ± 3.3° vs 20.4 ± 2.0°). We concluded that L. venusta clearly prefers to be associated with N. clavipes, and we discuss the possible advantages of this association.

The gravity hypothesis of sexual size dimorphism can explain the patterns of extreme sexual size dimorphism in spiders (males smaller than females) because small males climb faster and therefore may be better at reaching females that live in high habitats. Recently, the main prediction of a negative relationship between climbing speed and body size in spiders has been called into question. Here we induced males and females of the spider Leucauge venusta (Tetragnathidae) to run on vertical surfaces and found partial support for the gravity hypothesis. As predicted, males climb faster than females and we demonstrated that this effect is an indirect effect mediated by the negative relationship between body mass and climbing speed. We validate our results using simulated data showing that there is enough statistical efficiency in our data set to support our conclusions. We distinguished between direct and indirect effects (through mass) on sex differences in climbing speed by means of path analysis. Thus, we provide empirical evidence that by being smaller, males are able to climb faster than females. However, we found only a barely significant negative relationship between climbing speed and body size when only males were considered. Reasons for such results are discussed within the text.

Leucauge venusta USA: District of Columbia, near Rock Creek Park, 18.v.2007, Lopardo, Dimitrov, Álvarez-Padilla, ♂ ♀ (GWU, composite)., Published as part of Lopardo, Lara & Hormiga, Gustavo, 2015, Out of the twilight zone: phylogeny and evolutionary morphology of the orb-weaving spider family Mysmenidae, with a focus on spinneret spigot morphology in symphytognathoids (Araneae, Araneoidea), pp. 527-786 in Zoological Journal of the Linnean Society 173 (3) on page 734, DOI: 10.1111/zoj.12199, http://zenodo.org/record/5331625

The distribution of female Leucauge venusta (Walckenaer 1841) in a coffee plantation in southern Mexico was studied in order to determine the vertical distribution of this spider. Principal component analysis clearly identified the presence of three distinct groups of L. venusta webs, based on the number of spirals/web and principally on the height at which the webs were located; most L. venusta webs (63/100) were close to the ground. Spiders on high webs (153.8 ± 3.6 cm above ground, mean ± S.E.) were significantly larger and heavier than spiders on lower webs. Large spiders had significantly larger, better developed ovaries, than smaller conspecifics, presumably indicative of sexual maturity. Significantly more insects were captured by sticky traps placed at 50 cm height than in the traps placed at 150 cm height; the most numerous captures were Diptera. However, insects caught at 150 cm were significantly larger than those caught at 50 cm above ground. We concluded that as sexual development pr...

Why do kleptobiotic spiders of the genus Argyrodes seem to be associated with spiders of the genus Nephila worldwide? Observations following introduction of experimental insect prey of different sizes and weights on to host webs revealed that: (1) small prey are more effectively retained on the web of Nephila clavipes than on the web of another common host, Leucauge venusta. (2) N. clavipes did not consume small prey that accumulated on the web whereas larger, heavier prey were enveloped and stored. (3) We observed clear partitioning of prey items between N. clavipes and Argyrodes spp.; diet selection by Argyrodes did not overlap with that of N. clavipes but closely overlapped with that of L. venusta. (4) L. venusta responds very quickly to prey impact whereas N. clavipes is slower, offering a temporal window of opportunity for Argyrodes foraging. (5) The ability of L. venusta to detect and respond to small items also means that it acts aggressively to Argyrodes spp., whereas N. clavipes does not. Consequently, food-acquisition behaviours of Argyrodes were clearly less risky with N. clavipes compared with L. venusta. We conclude that when a kleptobiotic organism has a choice of various host species, it will opt for the least risky host that presents the highest rate of availability of food items. The fact that Nephila species present such characteristics explains the worldwide association with Argyrodes kleptobiotic spiders.

Sticky threads improve an orb web's ability to retain the insects that strike it, allowing a spider more time to subdue these insects before they can escape from the web. The adhesive capture threads found in most orb webs feature small droplets of aqueous material. Inside each droplet, glycoprotein granules coalesce to impart thread stickiness. An independent contrast analysis of threads produced by the adults of five species (Leucauge venusta, Argiope trifasciata, Micrathena gracilis, Cyclosa conica, Araneus marmoreus) and ontogenetic studies of the threads of two of these species show that the volume of material in a thread's droplets is directly related to its stickiness. Models based on these analyses predict thread stickiness to within an average of 11% of the mean measured values using measurements of droplet diameter and distribution that are easily made with a compound microscope. This approach will facilitate the inclusion of thread stickiness in studies that examine the properties and performance of spider orb-webs.

We documented the presence and abundance of spider species (Arachnida: Araneae) on young trees of Swietenia macrophylla, Ceiba pentandra and Cordia dodecandra found in an experimental plantation. Surveys of spider abundance and species identity conducted twice during the growing season indicated marked differences in web-building spider assemblages associated with each tree species. Swietenia exhibited the lowest spider abundance, whereas Cordia and Ceiba had similarly higher abundances. Leucauge venusta (Walckenaer, 1841) was the dominant spider on all tree species, but different spider species were co-dominant on Cordia and Ceiba (Araneus pegnia (Walckenaer, 1841) and Argiope argentata (Fabricius, 1775) respectively), and several spider species were exclusive to each tree species. These results highlight the influence of tree species identity on community structure at higher trophic levels, particularly in the case of web-building spiders inhabiting tropical tree communities.

This study focuses on the predatory capacity of four sympatric species of web- building spiders that inhabit coffee plantations in Southern Mexico: Gasteracantha cancriformis, Cyclosa caroli , and the morphologically similar species pair Leucauge marianaand L. venusta which were considered as one species group. The retention capabilities of the webs of these species and the incidence of prey capture and consumption were measured using eight types of insect prey belonging to the orders Coleoptera (1 species), Hymenoptera (3), Diptera (2) Lepidoptera (1) and Homoptera (1). The different characteristics of each prey such as body weight, body size, defensive behaviour, etc., were recorded. The incidence of prey retention, capture and consumption were significantly higher in G. cancriformis than in any of the other species. The lowest rates of retention, capture and consumption were observed in C. caroli, while L. mariana/venustawere intermediate in their predatory capabilities. Significant negative correlations between prey size and percent consumption were detected in L. mariana/venustaand in G. cancriformis; in both cases, large prey were less likely to be immediately consumed than small prey items. The results can be interpreted in the light of the morphological characteristics of the spiders. G. cancriformispossesses long legs and a carapace and appeared to have few difficulties to manipulate all types of prey. In contrast, C. caroli showed lesser abilities to manipulate and subdue aggressive prey items, perhaps due to the short leg length and unprotected body of this species. The consumption of prey items may be related to the predatory strategy of each spider. G. cancriformis constructs a new web every morning and prey storage was never observed. The absence of prey storage behaviour could explain why this species consumes prey soon after capture. In contrast, C. caroli constructs a permanent web and stores captured prey on a stabilimentum that may explain the very low incidence of immediate consumption of prey observed in this species.

The biogenetic law posits that the ontogeny of an organism recapitulates the pattern of evolutionary changes. Morphological evidence has offered some support for, but also considerable evidence against, the hypothesis. However, biogenetic law in behavior remains underexplored. As physical manifestation of behavior, spider webs offer an interesting model for the study of ontogenetic behavioral changes. In orb-weaving spiders, web symmetry often gets distorted through ontogeny, and these changes have been interpreted to reflect the biogenetic law. Here, we test the biogenetic law hypothesis against the alternative, the optimal foraging hypothesis, by studying the allometry in Leucauge venusta orb webs. These webs range in inclination from vertical through tilted to horizontal; biogenetic law predicts that allometry relates to ontogenetic stage, whereas optimal foraging predicts that allometry relates to gravity. Specifically, pronounced asymmetry should only be seen in vertical webs under optimal foraging theory. We show that, through ontogeny, vertical webs in L. venusta become more asymmetrical in contrast to tilted and horizontal webs. Biogenetic law thus cannot explain L. venusta web allometry, but our results instead support optimization of foraging area in response to spider size.

Leucauge venusta (Walckenaer, 1841) Figures 1���12 Epeira venusta Walckenaer, 1841: 90 (see comments below about types). Linyphia (Leucauge) argyrobapta White, 1841: 473. Type lost (Levi, 1980: 23), Male neotype designated herein, deposited in MNRJ col. number MNRJ 9038 (see comments below about types), from Rio de Janeiro, Brazil. NEW SYNONYMY. Epeira hortorum Hentz, 1847: 477. Tetragnatha 5 -lineata Keyserling, 1864: 145. Argyroepeira hortorum Emerton, 1884: 332; Keyserling, 1893: 333; Emerton, 1902: 192. Argyroepeira venusta McCook, 1894: 242. Leucauge argyrobapta Cambridge, 1902 b: 16, 1903: 438; Petrunkevitch, 1911: 355. Leucauge venusta (Walckenaer, 1841) F. O. P.- Cambridge, 1903: 441; Petrunkevitch, 1930: 266; Saito, 1933: 48; Kaston, 1948: 265; Archer, 1951: 6; Wiehle, 1967: 193; Levi, 1980: 25; Coddington, 1990: 17; Hormiga, Eberhard & Coddington, 1995: 324; Dondale et al., 2003: 51; ��lvarez-Padilla, 2007: 291; ��lvarez-Padilla & Hormiga, 2008: 540; Kuntner, Coddington & Hormiga, 2008: 177. Leucauge hortorum Banks, 1909: 163; Franganillo, 1936: 85. Leucauge mabelae Archer, 1951: 6. Notes on types: Cambridge (1903: 438), in pointing out that it was not possible to settle the identity of Leucauge argyrobapta ���with absolute certainty��� suggested that ���there is a strong probability��� that argyrobapta is a synonym of Leucauge formosa (Blackwall, 1863), the latter also collected in Rio de Janeiro. He also noted that the specimens of Leucauge formosa that he examined (which were part of the Keyserling collection) were ���specifically distinct��� from Argyroepeira hortorum (= L. venusta). Despite the noted uncertainty, Cambridge did explicitly equate argyrobapta with formosa (op. cit., p. 538). Fortunately, such synonymy was not followed by subsequent authors. Illustrations of the epigynum and male palp of Leucauge formosa done by H.W. Levi (and available on line at http://www.oeb.harvard.edu/faculty/levi/ leucauge.html) clearly show that this latter species is different from argyrobapta (Levi���s excellent illustrations are based on specimens from Rio de Janeiro, housed in the Keyserling Collection at the Natural History Museum in London, which according to Levi were probably borrowed from John Blackwall). Under these circumstances, the only way to settle the question of the taxonomic identity of Linyphia argyrobapta is to designate a neotype collected in the type locality (Rio de Janeiro), in fulfillment of the qualifying conditions for neotype designation stated in the ICZN (Art. 75.3). As it turns, Linyphia argyrobapta is a junior synonym of Epeira venusta. The type of Epeira venusta is an illustration by John Abbot from his unpublished manuscript on the spiders of Georgia (USA). Abbot���s original illustration is in the library of the Natural History Museum in London. Walckenaer (1841) used Abbot���s manuscript (p. 13, fig. 113) to describe Epeira venusta. A photocopy of Abbot���s illustration, in the Museum of Comparative Zoology, was examined by Levi (1980) for his redescription of Leucauge venusta. That the name venusta was published in 1841, and before Whites���s argyrobapta, is clear from White���s (1841: 473) footnote about Walckenaer���s work: ��� July 2. Since this paper was written the 2 nd volume of Walckenaer���s work has been published.��� It is in this second volume where the description of Epeira venusta was first published. Levi and Levi (1961: 54) also provide additional compelling evidence that Walckenaer���s description was published in 1841, and not in 1842 as stated in Bonnet (1945: 625). Neotypes: Neotype by present designation, male from Brazil, Rio de Janeiro, Botanical garden of the Museu Nacional do Rio de Janeiro, lat. - 22.90842, long. - 43.223547 21 VIII 2007, leg. Abel P��rez-Gonz��lez, Adriano B. Kury, Thiago S. Moreira, Dimitar Dimitrov and Gustavo Hormiga (deposited in MNRJ). Diagnosis: Many Leucauge species are very similar and identification can be difficult. Males of L. venusta can be distinguished from similar species [e.g., L. formosa (Blackwall, 1863)] by the orientation of the conductor, which is more parallel to the tegulum (Fig. 2 B���C) than in other similar species. The shape of the apical processes of the conductor is also characteristic (Fig. 2 A���F). Other male genitalic characters which are useful to distinguish L. venusta from similar congeners are: the size and position of the subtegulum with relation to the tegulum and the shape and size of the paracymbium. The epigynum (Fig. 3 B) is quite similar to that of L. formosa, however, size and shape of spermathecae in L. venusta is unique to this latter species (Fig. 3 A). Coloration and color pattern in both males and females of Leucauge are important and diagnostic. They often vary considerably among species with similar genitalic morphology, hence, facilitating the correct identification. In live specimens, the abdomen of L. venusta has four distinct red-orange markings (silvery when in alcohol) (Fig. 1 A���G). Two are ventral and two are dorso-lateral. The ventral markings are parallel and placed laterally on distal third of the abdomen. They join proximally to form a U shaped pattern. The dorsal markings start around the middle of the abdomen and extend parallel to each other. Description: Male (neotype of Linyphia argyrobapta, from Rio de Janeiro) Habitus as in Figure 4 A���D. When live, carapace (Fig. 5 D���F) yellowish with green markings along edges and center dorsally. Fovea well marked (Fig. 5 F). Leg coxae with yellowish bases, rest of legs bright green. Abdomen (Figs. 4 B���D; 5 G; 6 A) elongated, proximally with shiny silvery guanine bands and three thinner black lines dorsally ��� one in center, two more lateral. Two lateral dorsal lines change to red-orange coloration close to middle of abdomen and widen distally. Lateral sides of abdomen with thick shiny silver line close to its dorsal side followed by black line and another silvery line with some yellowish tones followed by bright green. Ventral side of abdomen proximally green with yellowish central mark proximally and thin yellow lateral lines. Distally with a central black area and two lateral red-orange markings forming a U-shaped pattern. Two shiny rounded spots placed just lateral to spinnerets ��� light yellow when alive, silvery white in alcohol. All colored lines meet on distal tip of the abdomen which is black. Total length 5.50. Cephalothorax 2.35 long, 1.95 wide, 1.16 high. Abdomen 3.15 long, 1.54 wide, 1.47 high. Clypeus height 0.7 times an AME diameter. Sternum (Fig. 5 D) dark brown; 1.05 long, 0.98 wide. Eyes almost the same size. Lateral eyes juxtaposed on short elevations (Fig. 5 A, F). Distance between PME 1.5 times their diameter. AME-ALE distance about three AME diameters. Distance between AME almost twice their diameter. PLE-PME distance three times one PME diameter. Chelicerae (Figs. 4 A; 5 A���C) yellowish, darker brown distally. Distal edge of paturon with three anterior and four posterior teeth. Femur I 1.2 times the length of cephalothorax. Pedipalp as in Figures 2 A���F; 6 C���G; 7 A���D. Palpal tibia length 0.78; cymbium length 0.58. Epiandrous fusules as in Figure 6 B. Femur of leg IV dorsally with two parallel rows of branched trichobothria extending over more than two thirds of its length. Palp as in Figures 2 A���E; 6 C���G; 7 A���D. Conductor and embolus connect to tegulum with common membrane (Fig. 2 E, F). Female (same locality and date as male neotype). Habitus and coloration as in male (Fig. 1 A���G), slightly larger than male (female total length ca. 1.3 times that of male). Total length 7.45. Cephalothorax (Fig. 8 A���C) 2.88 long, 2.06 wide, 1.32 high. Abdomen (Fig. 9 A���B) 4.57 long, 2.40 wide, 2.19 high. Clypeus height 0.5 times an AME diameter. Sternum (Fig. 9 B) dark brown; 1.39 long, 1.16 wide. Eyes sizes and distribution as in male (Fig. 9 A, E). Chelicerae as in male (Fig. 9 C���F). Tracheal system haplotracheate (Fig. 10 F���G), with median tracheal trunks shorter than lateral, neither of them entering the prosoma. Tracheal atrium with numerous accessory glands (Fig. 11 A). Tracheal spiracle immediately anterior to spinnerets. Spinnerets as in Figure 10 A���D. Femur IV dorsally with two rows of branched trichobothria as in male (Fig. 10 E). Epigynum as in Figures 2 A���B; 9 C���F; 11 B���G. Spermathecae (Figs. 3 A; 11 B, B) membranous and elongated. Fertilization ducts also membranous with numerous accessory glands (Fig. 11 C, E, F). Variation: Male cephalothorax length varies between 2.24 and 2.35 (n = 4). Females cephalothorax length varies between 2.30 and 3.00 (n = 117). Total body length in males varies between 5.11 and 5.50 (n = 4) and in females between 5.88 and 9.66 (n = 117). Distribution: Leucauge venusta is very widely distributed in the New World. Although, common in temperate areas of USA (Levi, 1980) this species has been already found in the neotropics (Panama, Colombia, see Cambridge, 1903) and its presence in Brazil extends further south its known distribution range. Leucauge venusta distribution spans from southern Canada to southern Brazil. Natural history: The natural history of L. venusta is relatively well known. Leucauge venusta spins its horizontal orb web (Fig. 12 A���F) in vegetation in humid tropical and temperate areas. Emerton (1902), Comstock (1913), Kaston (1947), Levi (1980) and H��naut et al. (2006) describe their webs. In more temperate areas it is commonly found in irrigated orchards, gardens or vegetation along river banks. The spider usually rests in the center of the web but when disturbed it hides in an off-web retreat. Leucauge venusta webs may vary considerably and in some cases they have a mesh above the orb plane. The variability in web architecture in this species was first noted by Darwin (as quoted in White, 1841: 474): ���... but sometimes above, the concentric web, there is an irregular or thin tissue of network ���. The web and foraging biology of L. venusta was also studied in detail by H��naut et al. (2001). The courtship behavior is described in detail by Castro (1995). Eberhard and Huber (1998) give further details and discuss the differences in the courtship among several Leucauge species., Published as part of Dimitrov, Dimitar & Hormiga, Gustavo, 2010, Mr. Darwin's mysterious spider: on the type species of the genus Leucauge White, 1841 (Tetragnathidae, Araneae), pp. 19-36 in Zootaxa 2396 on pages 24-33, DOI: 10.5281/zenodo.193975, {"references":["Walckenaer, C. A. (1841) Histoire naturelle des Insects. Apteres. Paris 2, 1 - 549.","White, A. (1841) Description of new or little known Arachnida. Annals and Magazine of Natural History, 7, 471 - 477.","Levi, H. W. (1980) The orb-weaver genus Mecynogea, the subfamily Metinae and the genera Pachygnatha, Glenognatha and Azilia of the subfamily Tetragnathinae north of Mexico (Araneae: Araneidae). Bulletin of the Museum of comparative Zoology Harvard, 149, 1 - 74.","Hentz, N. M. (1847) Descriptions and figures of the araneides of the United States. Boston Journal of natural History, 5, 443 - 478.","Keyserling, E. (1864) Beschreibungen neuer und wenig bekannter Arten aus der Familie Orbitelae Latr. oder Epeiridae Sund. Sitzungsberichte der Naturforschenden Gesellschaft Isis zu Dresden, 1863, 63 - 98, 119 - 154.","Emerton, J. H. (1884) New England spiders of the family Epeiridae. Transactions of the Connecticut Academy of Arts and Sciences, 6, 295 - 342.","Keyserling, E. (1893) Die Spinnen Amerikas. Epeiridae. Nurnberg, Germany 4, 209 - 377.","Emerton, J. H. (1902) The common spiders of the United States. Boston, pp. 1 - 225.","McCook, H. C. (1894) American spiders and their spinning work. Philadelphia 3, 1 - 285.","Cambridge, F. O. P. -. (1902 b) A revision of the genera of Araneae or spiders with reference to their type species. Annals and Magazine of Natural History, (7) 9, 5 - 20.","Cambridge, F. O. P. -. (1903) Arachnida - Araneida and Opiliones. In Biologia Centrali-Americana, Zoology. London, 2, 425 - 464.","Petrunkevitch, A. (1930) The spiders of Porto Rico. Part two. Transactions of the Connecticut Academy of Arts and Sciences, 30, 159 - 356.","Saito, S. (1933) Notes on the spiders from Formosa. Transactions of the Sapporo natural History Society, 13, 32 - 61.","Archer, A. F. (1951) Studies in the orbweaving spiders (Argiopidae). 1. American Museum Novitates, 1487, 1 - 52.","Wiehle, H. (1967) Meta, - eine semientelegyne Gattung der Araneae (Arach.). Senckenbergiana Biologica, 48, 183 - 196.","Coddington, J. A. (1990) Ontogeny and homology in the male palpus of orb-weaving spiders and their relatives, with comments on phylogeny (Araneoclada: Araneoidea, Deinopoidea). Smithsonian Contributions to Zoology, 496, 1 - 52.","Hormiga, G., Eberhard, W. G., & Coddington, J. A. (1995) Web-construction behaviour in Australian Phonognatha and the phylogeny of nephiline and tetragnathid spiders (Araneae: Tetragnathidae). Australian Journal of Zoology, 43, 313 - 364.","Dondale, C. D., Redner, J. H., Paquin, P., & Levi, H. W. (2003) The insects and arachnids of Canada. Part 23. The orbweaving spiders of Canada and Alaska (Araneae: Uloboridae, Tetragnathidae, Araneidae, Theridiosomatidae). NRC Research Press, Ottawa, Canada, 371 pp.","Alvarez-Padilla, F. (2007) Systematics of the spider genus Metabus O. P. - Cambridge, 1899 (Araneoidea: Tetragnathidae) with additions to the tetragnathid fauna of Chile and comments on the phylogeny of Tetragnathidae. Zoological Journal of the Linnean Society, 151, 285 - 335.","Kuntner, M., Coddington, J., & Hormiga, G. (2008) Phylogeny of extant nephilid orb-weaving spiders (Araneae, Nephilidae): testing morphological and ethological homologies. Cladistics, 24, 147 - 217.","Banks, N. (1909) Arachnida of Cuba. Estacion central agronomica de Cuba, Second Report. II: 150 - 174.","Franganillo, B., P. (1936) Los aracnidos de Cuba hasta 1936. Cultural, La Habana, Cuba, 183 pp.","Henaut, Y., Pablo, J., Ibarra-Nunez, G., & Williams, T. (2001) Retention, capture and consumption of experimental prey by orb-web weaving spiders in coffee plantations of Southern Mexico. Entomologia Experimentalis et Applicata, 98, 1 - 8.","Castro, Teresita de Jesus. (1995) Estudio comparativo del comportamiento reproductor, en las aranas del genero Leucauge (Araneae, Tetragnathinae), del Soconusco, Chiapas. Universidad de Ciencias y Artes del Estado de Chiapas, Mexico, Thesis Lic.","Eberhard, W. G., & Huber, B. A. (1998) Courtship, copulation, and sperm transfer in Leucauge mariana (Araneae, Tetragnathidae) with implications for higher classification. Journal of Arachnology, 26, 342 - 368."]}

Cribellar prey capture threads found in primitive, horizontal orb-webs reflect more light, including ultraviolet wavelengths, than viscous threads found in more derived, vertical orb-webs. Low web visibility and vertical orientation are each thought to increase prey interception and may represent key innovations that contributed to the greater diversity of modern, araneoid orb-weaving spiders. This study compares prey interception rates of cribellate orb-webs constructed by Uloborus glomosus (Uloboridae) with viscous orb-webs constructed by Leucauge venusta (Tetragnathidae) and Micrathena gracilis (Araneidae). We placed sectors of cribellar and viscous threads side by side in frames that were oriented either horizontally or vertically. The webs of both U. glomosus and L. venusta intercepted more prey when vertically oriented. In each orientation L. venusta webs intercepted more insects than did U. glomosus. Although this is consistent with the greater visibility of cribellar threads, the more closely spaced capture spirals of L. venusta may have contributed to this difference. Micrathena gracilis webs intercepted more prey than did U. glomosus webs, although web orientation did not affect the performance of this araneoid species. The stickier and more closely spaced capture spirals of M. gracilis may have enhanced the interception rates of this species and accounted for the greater number of smaller dipterans retained in its webs. The tendency for these slow, weak flight insects to be blown into both horizontal and vertical webs may account for similar interception rates of horizontal and vertical M. gracilis webs. These observations support the enhanced prey interception of vertically oriented orb-webs, but offer only qualified support for the contributions of lower visibility viscous capture threads.

Argyrodes globosus (Keyserling, 1884) is a small kleptoparasite spider that steals prey from the web of web-building spiders. In coffee plantations in the south of Mexico it was observed to parasitize five species: Gasteracantha cancriformis (Linnaeus, 1785) and Verrucosa arenata (Walckenaer, 1841) (Araneidae), Leucauge mariana (Keyserling, 1881) and Leucauge venusta (Walckenaer, 1841) (morphologically indistinguishable species) and Leucauge argyra (White, 1841) (Tetragnathidae). G. cancriformis was more frequently parasitized than the other hosts. An analysis of web diameter for each host species indicated that for L. mariana/venusta, L. argyra and V. arenata the kleptoparasite was associated with webs of a certain size range (23-33cm diameter) although a far larger range of web sizes was available (17-50cm diameter). The average size of the web of G. cancriformis (~23cm) appeared to be close to the preferred size for the kleptoparasite and this, together with an apparent absence of host aggression, may ...

For more than a century and a half the identity of Linyphia (Leucauge) argyrobapta White, 1841, the type species of the spider genus Leucauge, has been a mystery and an obstacle for revisionary work on this orb weaving genus. The only known specimen of argyrobapta, the type, was collected by Charles Darwin in Rio de Janeiro during the voyage of the H.M.S. Beagle and was lost after White’s description was published. We designate a neotype for Linyphia argyrobapta (White, 1841) based on specimens collected in the type locality. The common and widespread American species Leucauge venusta (Walckenaer, 1841) is a senior synonym of L. argyrobapta.