Hortophora biapicata (L. Koch, 1871) comb. nov.

Figs 1A-C, 2A, 3A, B, 6, 7, 8

Epeira biapicata Koch 1871: 54-55, plate 4, fig. 4.

Epeira frosti Hogg 1896: 315-316, plate 24, fig. 1. New synonymy.

Araneus biapicatifera Strand 1907: 202-205. New synonymy.

Araneus biapicatus (L. Koch).- Rainbow 1911: 182.

Araneus biapicatifera (Strand).- Rainbow 1911: 183.

Araneus frosti (Hogg).- Rainbow 1911: 186.

Araneus transmarinus (Keyserling).- Dondale 1966: 1164-1166, figs 2D-G (misidentification; synonymy rejected by Davies (1980) and herein).

Eriophora biapicata (L. Koch).- Davies 1980: 128-130, figs 9-15.

Type material.

Holotype of Epeira biapicata L. Koch, 1871: female, “Neuholland” (= Australia; no precise locality data in original description) (SMNH) (lost in WW2, see Davies 1980).

Neotype of Epeira biapicata L. Koch, 1871 (designated by Davies 1980): male, 64 km W of Westmar (ca. 27°59'S, 149°04'E, Queensland, Australia), R.J. Raven, V.E. Davies, 9 January 1979, mulga scrub (QM S361). Examined.

Holotype of Epeira frosti Hogg, 1896: female, Stevenson River (27°06'S, 135°32'E, South Australia, Australia), Horn Expedition (MV K-931). Examined.

Holotype of Araneus biapicatifera Strand, 1907: female, no exact locality, only given as “Australien” in Strand (1907) (MWNH 331). Microscopic photographs of the holotype examined.

Other material examined.

See Appendix 1.

Diagnosis.

Male and female H. biapicata comb. nov. are most similar to H. transmarina comb. nov. with which they share a comparatively large size and distinct ventral pattern of broad light transverse bands of the abdomen, particularly distinct just behind the epigastric furrow (Figs 1B, G, 6B, D, F, H, 24B, 25B). However, male H. biapicata comb. nov. differ from all other species of Hortophora gen. nov., including H. transmarina comb. nov., by the presence of coxal hooks on leg II (Fig. 7F). Female H. biapicata comb. nov. can be distinguished from those H. transmarina comb. nov. by the smaller baso-lateral flaps of the epigyne that bulge laterally in the latter and can be seen in ventral view (Fig. 25C), but not so in H. biapicata comb. nov. (Fig. 7G).

Description.

Male (HBI N18501-1): Total length 10.5. Carapace 6.2 long, 5.0 wide; reddish-brown, lighter in cephalic area (Fig. 6A). Eye diameter AME 0.34, ALE 0.16, PME 0.29, PLE 0.18; row of eyes: AME 0.85, PME 0.65, PLE 2.30. Chelicerae reddish-brown; three promarginal teeth (basal smallest), three retromarginal teeth (similar size). Legs dark brown, femora basally lighter, tibiae, metatarsi and tarsi with yellow brown rings or spots (Fig. 6A, B). Coxae of leg II with hook-like projections (Fig. 7F). Tibiae of leg II enlarged with strong prolateral spines, but no distinct apico-ventral megaspur (Figs 2A, 6A, B). Leg formula I> IV> II> III; length of segments (femur + patella + tibia + metatarsus + tarsus = total length): I - 6.5 + 3.5 + 6.1 + 6.0 + 1.5 = 23.6, II - 6.1 + 2.8 + 4.6 + 0.9 + 0.8 = 15.2, III - 4.1 + 1.6 + 2.7 + 2.6 + 0.9 = 11.9, IV - 4.7 + 1.9 + 4.2 + 4.4 + 0.8 = 16.0. Labium 0.80 long, 0.92 wide, dark brown (Fig. 6B); endites light brown. Sternum 2.9 long, 1.7 wide, brown and covered by yellowish setae (Fig. 6B). Abdomen 6.0 long, 4.3 wide; dorsum olive-brown with indistinct lighter folium pattern; venter olive-brown with light transverse band behind epigastric furrow (Fig. 6B). Pedipalp length of segments (femur + patella + tibia + cymbium = total length): 1.1 + 0.5 + 0.3 + 2.0 = 3.9; paracymbium elongated, strongly sclerotised (Fig. 7B); median apophysis elongate transverse with pointy central protrusion and apically bifid curved tips (Figs 5A, 7A, H); terminal apophysis bubble-shaped tapering into an elongated, sclerotised tip (Figs 5A, C, D, 7A); conductor with sclerotised apical and lamellar central portion (Fig. 7A); embolus heavily sclerotised, elongated with a sinuous tip (Figs 5D, 7A).

Female (HBI N26183-1): Total length 22.0. Carapace 8.7 long, 7.6 wide; reddish-brown, cephalic are darker; centrally covered with white setae (Fig. 6C). Eye diameter AME 0.36, ALE 0.27, PME 0.27, PLE 0.20; row of eyes: AME 0.92, PME 0.88, PLE 4.35. Chelicerae orange-brown; three promarginal teeth (similar size), three retromarginal teeth (basal largest). Leg femora reddish-brown, apically darker and without setae; all other segments very dark brown with bands of dark and white setae (Fig. 6D). Pedipalp length of segments (femur + patella + tibia + tarsus = total length): 2.5 + 1.1 + 1.8 + - + 3.2 = 8.6. Leg formula I> IV> II> III; and length of segments (femur + patella + tibia + metatarsus + tarsus = total length): I - 9.5 + 4.7 + 7.9 + 8.2 + 2.6 = 32.9, II - 8.6 + 4.2 + 7.5 + 0.9 + 2.4 = 23.6, III - 5.8 + 2.7 + 3.5 + 3.8 + 1.8 = 17.6, IV - 7.5 + 4.4 + 6.4 + 6.3 + 2.6 = 27.2. Labium 1.00 long, 1.68 wide, reddish-brown (Fig. 6D); endites as in male. Sternum 4.0 long, 3.0 wide, brown, covered by yellowish setae (Fig. 6D). Abdomen 12.5 long, 13.0 wide, indistinct humeral humps, dorsum dark olive-brown and mottled with light spots, central folium pattern darker (Fig. 6C); venter dark olive-brown with narrow light lateral lines and light transverse band behind epigastric furrow (Fig. 6D). Spinnerets brown. Epigyne (Fig. 7C-E) base ovoid; scape highly elongated and centrally slightly wider, dorsal narrow ridge in basal half (Fig. 7D), and covered with sparse short setae.

Variation.

Size variation: total length males 11.3-16.3 (n=17), females 15.0-23.1 (n=19). Unlike in other Hortophora gen. nov. species, the female scape was never broken off in any of the females examined by us. There is great colour variation, specifically in the abdomen of both males and females, which may be almost uniformly light to dark brown, or have a distinct folium pattern (e.g., Figs 1A, 6E, G) and often distinct white guanine markings, either just spots (in particular posterior of the humeral humps (e.g., Fig. 1A, 6C, G), or longitudinal or transverse spots and lines (e.g., Fig. 1C, 6E). These patterns are not species-specific, occur similarly in other species and cannot be relied on to identify H. biapicata comb. nov.

The species was named after the often discernible two tips at the end of the abdomen in females. However, these cannot be seen in all specimens, in particular not in gravid or fully fed females and cannot be relied upon as diagnostic character.

Remarks.

The holotype of Epeira biapicata L. Koch, 1871 was lost in WW2 when the Natural History Museum, Stuttgart was damaged. Davies (1980) designated a neotype for the species due to its similarities with H. transmarina comb. nov. to fix the taxonomic concept of the species-group name Epeira biapicata .

Two immature females from Ovalau (Fiji) (ZMH Rack (1961) -catalogue no. 225), Museum Godeffroy 7477) (examined) were mentioned in the original description and could potentially be considered part of the type series. However, we here follow Davies (1980) who excluded them from the type material as they were not explicitly described. Based on our examinations, Fiji does not belong to the distribution range of H. biapicata comb. nov. and it is likely that both specimens belong to H. viridis comb. nov., originally described from Fiji and here removed from synonymy with H. transmarina comb. nov. (see below), pending a more detailed review of orb-weaving spiders of the Pacific region.

The female holotype of Epeira frosti Hogg, 1896 (MV K-931) agrees well with the diagnosis of H. biapicata comb. nov. as presented here. It is therefore proposed as junior synonym of H. biapicata comb. nov. Detailed images of the female holotype of Araneus biapicatifera Strand, 1907 (MWNH 331) were examined and somatic and genitalic characters also match the diagnosis of H. biapicata comb. nov. presented here. Therefore, A. biapicatifera is here also proposed as junior synonym of H. biapicata comb. nov.

Life history and habitat preferences.

The large majority of mature males of H. biapicata comb. nov. has been found between January and March, with no records between August and October and very few in all other months. Mature females show an extended activity from January to May, with few records in all other months. Therefore, main reproductive activity of H. biapicata comb. nov. occurs in summer, extending into autumn for females. This coincides with the late wet season in northern Australia.

Eriophora biapicata comb. nov. can be found in almost all habitats that allow it to span its large orb-web between shrubs and trees. The species is also common in man-made environments, such as suburban parks and gardens.

Distribution.

Hortophora biapicata comb. nov. has been found throughout all Australian mainland states, but so far not in Tasmania (Fig. 8).