﻿Revision of the orb-weaver spider genus Gea C.L. Koch, 1843 (Araneae, Araneidae) from China

﻿Abstract The orb-weaver spider genus Gea C.L. Koch, 1843 from China is revised, and three species including one new species, are recognized: Geajingdong Mi, Wang & Gan, sp. nov. (♂♀) from Yunnan; Geaspinipes C.L. Koch, 1843 (♂♀) from Guangdong, Guangxi, Guizhou, Hainan, Taiwan, and Yunnan; and Geasubarmata Thorell, 1890 (♂♀) from Guangxi and Hainan. Geasubarmata is newly recorded in China.


Introduction
The orb-weaver spider subfamily Argiopinae consists of three genera, Gea C.L. Koch, 1843, Argiope Audouin, 1826, and Neogea Levi, 1983 (Levi 1983).This subfamily differs from other araneid subfamilies in having the posterior eye row procurved in dorsal view, and it is also characterized by sexual dimorphism (Levi 1983).The subfamily Argiopinae of the Western Pacific region has been revised by Levi (1983), who included in it 49 Argiope species, seven Gea species, and two Neogea species; eight species of Argiope occur in China, but no species of Gea were known from China.
The genus Gea contains 13 species and subspecies, which are mainly distributed in Africa, Asia, and Australia, and Gea heptagon (Hentz, 1850) is introduced to the USA to Argentina (WSC 2024).Gea spinipes has been almost concurrently reported from Guizhou and Yunnan (Yin et al. 1997) and Taiwan (Chang and Chang 1997) and is the only known Gea species known from China at present (Song et al. 1999;WSC 2024).
The Gea specimens collected in China were examined, and three species including a new species, are identified.They are described in this paper.

Material and methods
All specimens were collected by beating shrubs or by hand and are preserved in 75% ethanol.The specimens are deposited in the Museum of Tongren University, China (TRU).Methods follow Mi et al. (2023)  Diagnosis.Gea is distinguished from Argiope by having the posterior eyes about equally spaced, while Argiope has the posterior median eyes farther from the posterior lateral eyes than the posterior median eyes from each other (Levi 1983: figs 27, 45, 64).Gea differs from Neogea in having the cephalic region behind the eyes not swollen, while in Neogea this region of the head is swollen (Levi 1983: figs 290, 292).
Description.Small to medium-sized spiders with female total length of 3.65-9.00mm and male total length of 3.00-4.30mm.Carapace pear-shaped, yellow to yellowish brown.Legs yellow to yellowish brown, always with dark annuli; coxa I of male without hook; femur II of male without groove; tibia II of male not expanded.Abdomen shield-shaped dorsal often with a pair of low anterolateral humps in females, pale with a pair of dark patches close to humps and dark folium posteriorly or dark with white spots.Ventral abdomen pale with irregular dark patches or white spots.
Pedipalp of male without basal femoral protrusion; patella with only one bristle; paracybium fingerlike or flattened fingerlike; median apophysis bifurcated; dorsal ramus often weaker than ventral ramus; embolus extremely long and curved, thick at base, tapering to filiform end; conductor broad, curved, wrapped distal part of embolus.
Epigynum weakly sclerotized; median septum separating two depressions; copulatory openings situated on edges of depressions; copulatory ducts twisted, a bit longer than spermatheca; spermathecae elongate kidney-shaped, S-shaped, or bean-shaped, either touching or not.
Comment.Spination of femur I is not useful to characterize these Gea species.Diagnosis.The new species resembles G. spinipes in appearance and genitalia structures, but it can be distinguished as follows: 1) median apophysis not exceeding the conductor in prolateral view and retrolateral view (Fig. 2A, B) vs exceeding the conductor (Fig. 4A, B); 2) visible part of embolus curled about 90° in ventral view (Fig. 2C) vs about 180° (Fig. 4C); 3) conductor shorter, extending ventrally and not exceeding prolateral margin of pedipalp in ventral view (Fig. 2C) vs longer, extending ventro-prolaterally and the tip exceeding the prolateral margin of pedipalp (Fig. 4C); 4) copulatory openings situated on inner edges of the depressions (Fig. 1A) vs on anterior lateral edges (Fig. 3A); 5) lateral epigynal plates not covering the anterior rim in lateral view (Fig. 1B) vs covering the anterior rim (Fig. 3B); and 6) female carapace lacking dark brown patches (Fig. 1E, G) vs having dark brown patches (Fig. 3G, I

A B C D
thoracic region; base of eyes black.Cervical groove inconspicuous; fovea longitudinal.Chelicerae yellow, with four promarginal and three retromarginal teeth.Endites wider than long, yellow, with very narrow, dark anterior edges.Labium triangular, yellow.Sternum cordiform, yellow, with a wedge-shaped white patch posteriorly.Legs yellow to yellowish brown, with inconspicuous annuli; femur I with 12 macrosetae; tibia I with 12 macrosetae; tibia II with seven macrosetae; tibia III with seven macrosetae; tibia IV with seven macrosetae.Abdomen shield-shaped, ~1.31× longer than wide, grayish yellow, dorsal with a pair of dark brown patches anterolaterally and a dark brown folium posteriorly.Venter abdomen yellow with gray patches.Spinnerets yellow with gray tip.Pedipalp (Fig. 2): paracybium fingerlike; median apophysis bifurcated; dorsal ramus weaker than the ventral one; embolus thick at base, twisted and tapered into a fine tip; conductor membranous, curled, about 2× longer than wide in retrolateral view.
Epigyne (Fig. 1A-D): ~1.36× wider than long in ventral view, with a distinct median septum separating two depressions; copulatory openings situated on inner edges of the depressions; copulatory ducts widest at the beginning part, a bit longer than spermatheca; spermathecae almost S-shaped in dorsal view, not touching.
Epigyne (Fig. 4A-F): ~1.3× wider than long in ventral view, with a distinct median septum separating two depressions in ventral view; copulatory openings situated on anterolateral edges of depressions; copulatory ducts twisted, a bit longer than spermatheca; spermathecae elongate kidney-shaped, touching or nearly touching at midline.
Variation.Total length: ♂ 3.25-4.00(n = 8); ♀ 3.65-6.90(n = 8).Tip of embolus always broken.Comment.Gea spinipes is widely distributed from Pakistan to Indonesia, and shows some differences in epigynal structure of specimens collected from different sites (Levi 1983: figs 362-370) and that may indicate they are not conspecific.So, further taxonomic study about this species is necessary, especially getting more male specimens from different sites.G. zaragosa described by Barrion and Litsinger (1995) is similar to G. spinipes both in habitus and genitalia structures, but no detailed diagnosis was provided.Judging from the illustrations, G. zaragosa Barrion & Litsinger, 1995 is probably synonymized with the former.