The new Australian leaf-curling orb-weaving spider genus Leviana (Araneae, Araneidae)

The new Australian orb-weaving spider genus Leviana gen. nov. is described to include five species, all known from both sexes: Leviana dimidiata (L. Koch, 1871) comb. nov. (type species) (= Epeira sylvicola Rainbow, 1897 syn. nov. ), L. cincinnata sp. nov. , L. folium sp. nov. , L. minima sp. nov. and L. mulieraria (Keyserling, 1887) comb. nov. Male pedipalp morphology, specifically the presence of a single patella spine and the median apophysis forming an arch over the radix, place Leviana gen. nov. in the informal Australian ‘backobourkiine’ clade; however, the genus differs from all other genera of this group by the presence of a spine inside the basal median apophysis arch of the male pedipalp, an epigyne that is wider than long with a scape that is approximately as long as the epigyne (but often broken off) and a lack of humeral humps on the elongate ovoid abdomen. In addition, unlike any other backobourkiine, Leviana gen. nov. incorporate a rolled leaf as retreat into the periphery of their web. Leviana gen. nov. species exhibit only a moderate sexual size dimorphism with female to male ratios between 1.3 and 1.7. Leviana gen. nov. occurs in eastern Australia from northern Queensland in the north to Victoria in the south, with a single tropical species, L. mulieraria comb. nov. , spreading into northern Western Australia.


Introduction
Recent comprehensive phylogenetic studies on the orb-weaving spiders in the family Araneidae Clerck, 1757 have transformed our understanding of the systematic relationships within this family Kuntner et al. 2019;Scharff et al. 2020), although the limitations of the Araneidae itself remain contentious (Kallal et al. 2020). This is in part due to the unresolved family taxonomy at the base of "araneids", i.e. the families Araneidae some affinities to the Nearctic 'eriophorines' (but apparently more closely related to the morphologically more derived 'gasteracanthines'), and the 'zealaraneines' with closer phylogenetic affinities to traditional araneine genera, including Araneus Clerck, 1757 itself (Scharff et al. 2020). The Australian backobourkiines are the subject of an ongoing, comprehensive project with the aim to taxonomically revise all its constituent Australian genera and to formalize the subfamily once it can be diagnosed (e.g., Framenau et al. 2010Framenau et al. , 2021aFramenau et al. , b, 2022Framenau 2011).
Two morphological characters of the male pedipalp have been hypothesised as synapomorphies of the backobourkiines, i.e., the presence of a single patellar spine (e.g. two in the 'eriophorines' or 'zealaraneines') and the base of the median apophysis forming an arch over the radix (Scharff et al. 2020). These characters are also present in Araneus dimidiatus (L. Koch, 1871), an Australian species that did not group with the backobourkiines in Scharff et al.'s (2020) analysis, but formed a clade with Dolophones Walckenaer, 1837 and Cyclosa Menge, 1866, albeit with no statistical support. An earlier transcriptomic analysis also suggested affinities of A. dimidiatus with the backobourkiines, either as sister to Hortophora transmarina (Keyserling, 1865), or sister to H. transmarina and Plebs eburnus (Keyserling, 1886) combined, but those analyses included fewer putative backobourkiine taxa .
Araneus dimidiatus was described as Epeira dimidiata Koch, 1871 from female material collected in Port MacKay, Queensland. An apparently similar species, Araneus sylvicola (Rainbow, 1897) was subsequently described as Epeira sylvicola Rainbow 1897 based on a female collected in Guildford, New South Wales. Rainbow (1897) detailed the web-building and preycapture behaviour of this species (pg. 539): "Speaking generally, the Epeiridae do not all construct tube-nests or retreats. Among those that do so, Epeira wagneri [now a junior synonym of Phonognatha graeffei (Keyserling, 1865)] and E. sylvicola are never seen resting at the centre or "hub", as is the usual custom with orb-weavers; on the contrary, they are always to be found within their rolled-leaf nests. Whenever an insect becomes entrapped within the mesh, these spiders immediately rush out and enswathe the struggling victim in the usual manner of the Epeiridae." Indeed, the somatic morphology of A. dimidiatus, specifically the ovoid, cylindrical abdomen lacking any humps or processes (e.g., Figs 1C, 6A, 7A), caused many misidentifications in collections as Phonognatha Simon, 1895, a member of the Phonognathidae sensu Kuntner et al. (2019), or "Zygiellinae" Wunderlich, 2004) -a junior synonym of Phonognathinae. There are clear differences among the web architecture between Phonognatha and A. dimidiatus, however. Phonognatha has architectural elements of the web that are known in phonognathids and nephilids and not araneids, such as late radii and temporary spiral in the complete web, which A. dimidiatus lacks, and furthermnore, the leaf retreat of Phonognatha opens at the hub (Kuntner et al. 2008), whereas the leaf retreat of A. dimidiatus is placed and opens at the periphery of the orb (e.g. at its upper frame, see Fig. 1). These differences hint at convergently evolved leaf retreat solutions in these taxa.
Genital morphology of A. dimidiatus is typical backobourkiine. Comprehensive investigation of the type material and araneids from Australian museum collections revealed that A. dimidiatus and A. sylvicola are the same species and that Araneus mulierarius (Keyserling, 1887) is morphologically closely aligned. In addition, we found three further undescribed araneids in Australian collections apparently closely related to these species. The aim of this study is to revise all Australian species morphologically related to A. dimidiatus in a new genus as testable hypothesis for future systematic work, specifically to elucidate phylogenetic relationships of the new genus to or within the backobourkiines.

Taxonomy
Descriptions and terminology follow recent publications on backobourkiine orb-weaving spiders (e.g. Framenau et al. 2021aFramenau et al. , b, 2022. Colour patterns were described based on specimens preserved in ca. 75% EtOH. Redescriptions of historically named species are based on recently collected, well-preserved, material in lieu of often damaged and discoloured type specimens. To evaluate critical sclerites, a male pedipalp of A. dimidiatus was detached and expanded by alternatively submerging it for 10 min in 10% KOH and distilled water until fully expanded ( Fig. 5A-C). Sclerite nomenclature follows that in previous studies on backobourkiines, e.g. the use of 'conductor lobe' in lieu of 'paramedian apophysis' (e.g. Framenau et al. 2021a;Framenau et al. 2021b) and terminal apophysis for a prominent distal part of the embolic division (Framenau et al. 2022). The description of the views of the male pedipalp relate to their position as a limb, taking into consideration the araneid twist, i.e. the cymbium is situated mesally. We therefore consider our standard views of the left pedipalp ventral (i.e. with the cymbium to the left of the image) -to particularly illustrate the generally diagnostic median apophysis -or dorsal (i.e. with the cymbium to the right of the image)with the subtegulum and tegulum in full view.
The two main parts of the female epigyne are referred to as base (encapsulating the internal genitalia) and the scape. We refer to the central part of the base in ventral view as atrium which, in posterior view, becomes the central division. We removed and cleared selected epigynes to illustrate internal genitalia by submerging them in warm, 10% KOH for approximately 20 min. For observation and imaging, they were transferred into lactic acid on a microscopic glass slide under a coverglass which further cleared internal structures (Fig. 6A, B).
Microscopic images were taken in different focal planes (ca. 20-30 images) on a Leica DMC4500 digital Leaf retreat with female (not seen) feeding on dragonfly prey. camera mounted to a Leica M205C stereomicroscope and combined using the Leica Application Suite X, v. 3.6.0.20104. All photos were edited with Photoshop CC 2020 and combined into plates with Microsoft PowerPoint. Specimens were prepared for SEM imaging (Figs 2A-D, 3A-F) by passing morphological preparations through graded ethanol series of 70% to 100%, and by subsequent critical point drying in a Baltec CPC-030 Critical Point Dryer. Specimens were then coated with Platinum-Palladium in a JEOL JFC-2300HR high resolution coater prior to scanning at 7kV in a JEOL JSM-6335F Field Emission Electron Microscope.
All measurements are taken from adults and are given in millimeters. They were taken with an accuracy of one tenths of a millimetre, with the exception of eye and labium measurements taken with an accuracy of one hundredth of a millimetre.
Maps were compiled in the software package QGis v. 3.22.3 Białowieża (https://qgis.org/en/site/; accessed 11 February 2022). Geographic coordinates were extracted directly from original labels or the registration data as provided by the museums. When no detailed geographic information was available, localities were estimated to the closest minute based on Google Earth Pro v. 7.3.4.8248 (https://earth.google.com/web/; accessed 11 February 2022).
The taxonomic part of this study lists all species in alphabetical order, except for the type species of the new genus, which is treated first.

Results
The new genus Leviana gen. nov. is reasonably common in its distribution range; a total of 218 males, 717 females, and 227 juveniles in 426 records (= vials) were examined for this study (Table 1). Based on standard diagnostics, we recognise five species, three of which are new to science (Table 1). Leviana gen. nov. mostly inhabits eastern Australia, although the tropical L. mulieraria comb. nov. is also found in northern Western Australia (Table 1). Leviana gen. nov. has so far not been found in Tasmania.

Web architecture and natural history
Females of L. dimidiata comb. nov. construct two-dimensional, vertical aerial orb webs with a V-shaped open sector among low vegetation (Fig. 1A, B). The web always has the addition of a dry rolled leaf as retreat (Fig. 1A, D). The retreat is positioned at the top frame within the V-shaped open sector of the orb (Fig. 1A). Typically, the leaf is sealed on top, thus the retreat has a single opening in the lower part ( Fig. 1 D). A signal line connects the retreat with the hub. The hub, which is located centrally within a circular orbweb, is closed, with regularly spaced hub loops followed by a gap, a so-called abrupt transition to the catching spiral (Kuntner et al. 2008). Unlike the webs of an unrelated, but approximately co-distributed species Phonognatha graeffei, Leviana gen. nov. webs contain no late radii, meaning that all radii originate at the hub.
Juveniles and females remain in their retreats during the day. No males were found in female webs despite careful searching in the retreats. A female was observed feeding, from her retreat, on a large libellulid dragonfly, but no other prey types are known. No predators of Leviana gen. nov. are currently known, but their webs were occupied by theridiid symbionts. Type species. Epeira dimidiata L. Koch, 1871 (designated here).
Description. Small to medium-sized (total length males ca. 2.0-7.0, females 2.5-10.0 mm) orb-weaving spiders, with males slightly smaller than females. This difference in the size of sexes can be considered as very moderate sexual size dimorphism (Kuntner and Coddington 2020). Carapace (e.g. Figs 7A, 8A, 10A, 11A, 17A, 18A) longer than wide, pear-shaped; centre of cephalic region protruding more in males than in females; fovea poorly demarcated both in males and females forming a shallow pit; colouration brown in variable shades, sometimes with darker lateral flanks and cephalic area generally lighter; weak white pubescence both in males and females, particularly in the cephalic area. Eyes: anterior median eyes largest, their row wider than that of posterior median eyes; row of posterior eyes slightly recurved; lateral eyes almost touching and separated by more than their diameter from posterior median eyes; lateral eye groups elevated, a small horn of this elevation protrudes anteriorly. Sternum longer than wide. Labium wider than long, subtriangular, front end bulging and white. Maxillae with large lateral tooth present in males. Chelicerae with 4 (rarely 3) promarginal teeth, 3 (rarely 2) retromarginal teeth, Legs: leg formula I > II > IV > III; tibiae I and II in males strong in some species with more distinct spines, specifically prolaterally (e.g. Figs  12A, B, 15A, B, 17A, B); coxae I of male with hook and femora II with opposing groove. Abdomen longer than wide; ovoid to cylindrical, slightly dorsoventrally flattened in some species (e.g., Figs 7A, 8A, 12A, 13A, 17A, 18A); booklung covers with grooves; dorsum of abdomen uniform with some dark or light markings (Figs 7A, 8A, 10A, 11A) or with more or less distinct folium pattern (e.g., Figs 12A, 13A, 15A, 16A); ventral abdomen centrally light to dark grey, generally with lateral irregular guanine bands (e.g., Figs 8B, 10B, 13B, 18B).
Pedipalps (Figs 7C, D; also 4A, B, 5A-C): median apophysis apically broadly lobed, basally with thorn opposing a hooded base; terminal apophysis fleshy, elongated with double-tip; embolus with broad base, curved and short tip; conductor wider than high in ventral view.
Epigyne (Fig. 8C-F) ovoid wider than long, atrium bulging; central division broadly oval with narrow base; scape with almost parallel lateral border, almost translucent; often broken off anteriorly; spermathecae ovoid, almost touching centrally; fertilization duct very slightly curved and attaching laterally at atrium (Fig. 6A).
Variation. Males total length 4.8-6.6 (n = 5); females total length 6.4-9.9 (n = 7). There is little colour variation in males and females of this species, although the posterior part of the abdomen might be darker than in the specimens illustrated. Two out of seven females measured for this study had their epigyne scape intact.
Remarks. Rack (1961) considered a female in the ZMH the holotype of Epeira dimidiata, however, two further females from the type locality lodged in the NHMUK clearly bear the typical labels of L. Koch which suggests these to by syntypes. The original description does not state the number of specimens on which the description was based, and we therefore con- The syntypes of Araneus sylvicolus (Rainbow, 1897) are clearly conspecific with those of L. dimidiata comb. nov. based on genitalic and somatic morphology, con-sidering the intraspecific variation as described here. We therefore consider E. sylvicola Rainbow, 1897 a junior synonym of L. dimidiata (L. Koch, 1871) comb. nov.
Life history and habitat preferences. Adult males were mainly found between September and January, with a peak in November. Mature females were mainly found between September and April, with two peaks in December and February.
Records of L. dimidiata comb. nov. are from a variety of open and closed forests and woodlands, including those of eucalypt, Casuarina and Melaleuca. However, there are also some records from heathlands and vine scrubs.
Distribution. Eastern Australia from far north Queensland to eastern Victoria (Fig. 9). Etymology. The specific epithet is an adjective in apposition (cincinnatus Latin -curly) and refers to the leaf-curling behaviour of this species and other species in the genus.
Diagnosis. Leviana cincinnata sp. nov. differs distinctly from all other species in the genus by its uniform olive-grey abdominal colouration with only a white patch antero-centrally. All other species of Leviana gen. nov. have some dark to black abdominal markings. Male genital morphology is most similar to L. dimidiata comb. nov. due to the broadly lobed tip of the median apophysis and the strong spine in the basal arch of the median apophysis, but both species distinctly differ in the strong sclerotization of the conductor in L. dimidiata comb. nov., that is absent in L. cincinnata sp. nov. (Fig. 7C vs Fig. 10C). The epigyne scape is much broader than in any other species of Leviana comb. nov.
Variation. Male total length 3.3-4.1 (n = 4); females 5.4-7.5 (n = 8). There are additional white speckles on the abdomen and white discontinuous lateral bands on the abdomens of some males and females. The epigyne scape was broken in all females measured here, with the exception of two, including the one illustrated. The colouration of live specimens is not known, but it is possible that this species displays greenish or even reddish shades when alive, which often fade into yellow-brown when preserved in ethanol.
Life history and habitat preferences. Mature males of L. cincinnata sp. nov. were almost exclusively found between October and December. Mature females were found between October and January, although some were found in April and one in July.
Variation. Males total length 3.9-5.1 (n = 8), females 4.9-7.9 (n = 10). Colour variations of this species include, particularly in females, a distinct dark posterior patch that is sometimes poorly defined and sometimes distinctly demarcated. The epigyne scape was broken off in nine of the ten specimens measured.
Life history and habitat preferences. Mature female L. folium sp. nov. were found throughout the year with the exception of July and August and peak numbers were recorded between December and April. Two females with eggsacs were collected in January and March. Males were collected between October and April (with a single record from the NT in June). This species therefore is spring-to summer mature.
Most specimens of L. folium sp. nov. were found in rainforest, but some specimen labels list 'open forest' and 'vine scrub' as habitat.
Distribution. Leviana folium sp. nov. has been found in Queensland and New South Wales between ca. 16°45'S and 34°45'S Latitude, generally on the eastern slopes of the Great Dividing Range (Fig. 14). Etymology. The specific epithet is an adjective in apposition (minimus, Latin -smallest) and refers to the small size of the species in comparison to all other Leviana gen. nov. species.
Variation. Males total length 1.8-2.1 (n = 4), females 2.0-3.0 (n = 12). Colour variations of this species mainly occur on the abdomen, where the folium pattern can be more or less distinct. The scape was broken off in all but two of the 12 females measured.
Life history and habitat preferences. Mature females of L. minima sp. nov. have been found between October and June, and mature males between October and May. Curiously, no females were found in February and no males in January, indicating that there may be two reproductive periods throughout the year, one in spring and one in late summer.
Many of the specimens of L. minima sp, nov. were collected at altitudes from altitudes higher than 800 m, suggesting a preference for mountainous regions. Here the spiders have been largely found in rainforest. In contrast to other species of Leviana gen. nov., there are no records of L. minima sp. nov. that describe leaf-curling behaviour.
Variation. Males total length 3.6-5.0 (n = 2), females 5.0-7.3 (n = 6). Colour variations of this species mainly relate to the abdomen, where the folium pattern can be more or less distinct (e.g. compare male and female in Figs 17A, 18A). The scape was broken off in all six female specimens measured.
Remarks. The holotype of Epeira mulieraria, described from a male of the Bradley collection, appears to be lost (see also Framenau 2005) as it could not be found in any of the historic museum collections in which Keyserling's type material is deposited. However, the unique morphology of this species including its distinct abdominal colouration leave no doubt about the identity of this species and it is not considered necessary to designate a neotype here.
Life history and habitat preferences. Collecting numbers of L. mulieraria comb. nov. are too low for an interpretation of its life cycles. Mature females were found from January to March, in May, August and October, mature males in March, May, August and October to November. Adults of this tropical species were therefore collected both in the wet and the dry seasons. Habitat descriptions include rainforest and vine thickets.
Distribution. Leviana mulieraria comb. nov. has been found in tropical northern Queensland, Northern Territory and Western Australia north of 16°S (Fig. 14).

Discussion
The single patellar spine on the male pedipalp and the basal arch of the median apophysis identify Leviana gen. nov. as member of the informal backobourkiine clade, although the most recent multigene molecular analyses on world-wide Araneidae did not support this placement (Scharff et al. 2020). In that analysis, Leviana gen. nov. (as "NGEN03") grouped with Dolophones and Cyclosa as sister group to the Australasian spiny orb-weavers ('gasteracanthines') albeit without statistical support. However, that analysis (Scharff et al. 2020) suffered from low nucleotide data density intended to solve an overwhelming taxon sampling, and thus its topologies should be interpreted as preliminary. Genomic-scale analyses of Araneidae had previously supported the placement of Leviana gen. nov. (represented by L. dimidiata comb. nov.), Dolophones and Cyclosa as sister groups to backobourkiine species , although that study only used single representatives for each genus and only included two other backobourkiine terminals (Hortophora and Plebs). In contrast, Scharf et al.'s (2020) study included 13 terminals representing at least ten putative backobourkiine genera. More comprehensive analyses, possibly also including more molecular markers, key morphological characters and even more taxa, are required to resolve the phylogenetic relationships of Leviana gen. nov. and the backobourkiines as a whole. This initially requires further taxonomic studies at the genus level, for example the speciose backobourkiine genera Acroaspis and Carepalxis have not been treated taxonomically in detail since their original descriptions and a selection of representative species for such an analysis is currently not possible. However, our taxonomic study suggests that Scharff et al.'s (2020) clade consisting of Leviana gen. nov., Cyclosa and Dolophones is more likely backobourkiine, based on the presence of one of the putative synapomorphies of the clade in all genera, the basal arch of the median apophysis in the male pedipalp, or sister to the backobourkiines rather than sister to gasteracanthines with very different somatic and genitalic morphology.
The basal arch of the median apophysis in the male pedipalp is considered one of the synapomorphies of the backobourkiines. In Leviana gen. nov. this arch has an internal spine-like protrusion, one of the defining characters of the genus. The role of this spine is not known but it is perceivable that it provides some mechanical control during copulation. Assuming the median apophysis arch provides a joint with the radix that extends during copulation, the spine may provide a better connection or some resistance to limit that extension. Similarly, small tubercles are present inside the arch in the backobourkiine genus Salsa (Framenau and Castanheira 2022), but also in Dolophones (N. Scharff pers. comm. to VWF). The arch of the median apophysis is also modified in Backobourkia, where it carries an apically directed outer long flange (Framenau et al. 2010). This structure is likely to have a very different mechanical role compared to internal tubercles or spines. Only detailed studies imaging male and female genitalia during copulation will be able to solve question in relation to the mechanical role of the median apophysis arch and its modifications.
In museum collections, Leviana gen. nov. species have sometimes been identified as Phonognatha. Phonognatha is an atypical araneid (Kuntner et al. 2008;, possibly better classified as phonognathid (Kuntner et al. 2019), which builds orb webs with leaf retreats. However, in addition to a distinct non-araneine morphology (Rainbow 1897)), Phonognatha web architecture differs from Leviana gen. nov. and in certain elements resembles nephilids in retaining the non-sticky (also termed auxiliary or temporary) spiral in finished web (Hormiga et al. 1995;Kuntner et al. 2008). Phonognatha webs also contain three-dimensional additional threads above the orb, secondary radii that originate distally from the hub (Kuntner et al. 2008) and the leaf retreat in Phonognatha is at the hub, not at the top in the web periphery. The origin of leaf retreats is clearly not homologous in phonognathids/phonognathines (Phonognatha, Artifex, Deliochus) and in Leviana gen. nov.
All of the revised five species of Leviana gen. nov. are known from both sexes and we report their detailed size variation. These data imply that Leviana gen. nov. is only moderately sexually size dimorphic with female to male size ratios between 1.3 (L. minima) and 1.7 (L. cincinnata). These values do not approach the arbitrarily set threshold of extreme sexual size dimorphism at 2.0 known to have evolved in several other araneid clades (Kuntner and Coddington 2020). However, if the future tests confirm that the phylogenetic position of backobourkiine genera is relevant for gasteracanthines-a spider clade well known for extremely sexually dimorphic genera-, the here reported size data may be relevant for reconstructions of sex specific size evolution in araneids (e.g., Cheng and Kuntner 2014;Yu et al. 2022) and other orb-weavers (Kuntner et al. 2019), which can inform on the bigger picture of the patterns and causes of the evolution of sexual size dimorphism in spiders (Kuntner and Elgar 2014;Kuntner and Cheng 2016;Kuntner and Coddington 2020).
Leviana gen. nov. is currently only known from Australia, supporting the country as biogeographic origin of all backobourkiines. The potential inclusion of Cyclosa in the backobourkiines raises some interesting biogeographical questions. All backobourkiines sensu Scharff et al. (2020), but also Leviana gen. nov. and Dolophones, appear to be of Australian origin with few species found in neighbouring islands such as Papua New Guinea, New Caledonia and New Zealand -Plebs being distributed into South-East Asia and India being the most widespread. In contrast, Cyclosa has an almost cosmopolitan global distribution (World Spider Catalog 2022). This presents at least two intriguing biogeographic hypotheses, either the backobourkiines being derived from Cyclosa-like ancestors, or Cyclosa being of Australian origin with probably the most extensive Australian-born radiation at least in spiders.