Araneus arcuatus sp. nov.

Figs 1, 2, 18A-D

Type material.

Holotype ♂ (IZCAS-Ar43081), China: Yunnan, Xishuangbanna, Mengla County, Menglun Township, Menglun Nature Reserve, XTBG (21°54.18'N, 101°16.90'E, ca 610 m), 5.V.2019, Y.F. Tong leg. Paratypes: 1♂ (IZCAS-Ar43082), same data as holotype; 1 ♀ (IZCAS-Ar43083), secondary tropical forest, bamboo plantation along G213 roadside (21°53.82'N, 101°16.99'E, ca 610 m), 3.VIII.2018, Z.L. Bai leg.; 1♂ (IZCAS-Ar43084), G213 roadside near Lüshilin (21°53.91'N, 101°17.01'E, ca 620 m), 12.VIII.2018, C. Wang leg.; 2♂2♀ (IZCAS-Ar43085-43088), Masuoxing Village (21°54.02'N, 101°16.90'E, ca 560 m), 27.IV.2019, Y.F. Tong leg.; 1♂ (IZCAS-Ar43089), #3 site around the dump (21°54.34'N, 101°16.79'E, ca 620 m), 2.V.2019, Y.F. Tong leg.; 1♀ (IZCAS-Ar43090), #6 site around the dump (21°54.33'N, 101°16.79'E, ca 620 m), 7.V.2019, Y.F. Tong leg. Other material examined: 1♂ (IZCAS-Ar43091), 55 km from Xishuangbanna National Nature Reserve, artificial Ficus microcarpa forest (21°54.97'N, 100°16.05'E, ca 610 m), 21.VIII.2011, Q.Y. Zhao leg.; 1♂ (IZCAS-Ar43092), Mohan Township, Shanggang Village, Xiaolongha, seasonal rainforest (21°24.19'N, 101°37.03'E, ca 660 m), 29.VI.2012, Q.Y. Zhao & Z.G. Chen leg.; 1♀ (IZCAS-Ar43093), same locality (21°24.33'N, 101°37.02'E, ca 800 m), 30.VI.2012, Q.Y. Zhao & Z.G. Chen leg.; 1♀ (IZCAS-Ar43094), Mengla Township, Bubang Village (21°36.64'N, 101°34.91'E, ca 820 m), 10.VII.2012, Q.Y. Zhao & Z.G. Chen leg.; 1♂ (IZCAS-Ar43095), #3 site in Mafengzhai Village (21°53.68'N, 101°17.33'E, ca 540 m), 8.V.2019, Y.F. Tong leg.; 1♀1♂ (IZCAS-Ar43096), Lüshilin Forest Park (21°53.84'N, 101°16.84'E, ca 550 m), 10.V.2019, Z.L. Bai leg.

Etymology.

The specific name is derived from the Latin word “arcuatus”, meaning arcuate (curved), referring to the shape of the median apophysis in prolateral view.

Diagnosis.

The female of the new species resembles that of A. cucullatus sp. nov. in appearance but can be distinguished from it as follows: 1) epigyne about 1.65 times wider than long vs about 2 times wider than long (Fig. 10A); 2) copulatory openings situated on the ventral surface vs the posterior surface (Fig. 10B); 3) spermathecae touching each other vs separated (Fig. 10C); and 4) abdomen lacking sparse, long setae vs having sparse, long setae (Fig. 10D). The male of the new species resembles that of A. tetracanthus sp. nov. in appearance but differs as follows: 1) median apophysis has 2 tapered tips vs 4 tapered tips (Fig. 17); 2) tegulum lacks an extension vs with a tegular extension (Fig. 17); and 3) embolus shorter than half of the bulb diameter vs longer than half of the bulb diameter (Fig. 17D).

Description.

Male (holotype, Figs 1C, D, 2, 18A-D). Total length 2.45. Carapace 1.20 long, 1.00 wide. Abdomen 1.35 long, 0.95 wide. Clypeus 0.10 high. Eye sizes and interdistances: AME 0.10, ALE 0.08, PME 0.10, PLE 0.08, AME-AME 0.13, AME-ALE 0.08, PME-PME 0.13, PME-PLE 0.10, MOA length 0.30, anterior width 0.28, posterior width 0.28. Leg measurements: I 3.85 (1.10, 1.35, 1.00, 0.40), II 3.70 (1.10, 1.30, 0.90, 0.40), III 2.45 (0.80, 0.75, 0.60, 0.30), IV 3.35 (1.05, 1.10, 0.85, 0.35). Carapace pear-shaped, yellow, cervical groove slightly distinct, fovea transverse, inner base of PMEs elevated. Chelicerae yellow, 3 promarginal and 3 retromarginal teeth. Endites almost square, yellow with very narrow, dark anterior edge, labium triangular, yellowish brown with yellow edge. Sternum cordiform, yellow with dark setae. Legs yellow without annulus, tibia I with 13 macrosetae, tibia II with 8 macrosetae. Abdomen elliptical, about 1.4 times longer than wide, in life, light yellowish green or grayish yellow when preserved with inconspicuous, white scaly spots; venter grayish yellow with inconspicuous, white scaly spots. Spinnerets yellow.

Palp (Fig. 2): 2 patellar bristles; median apophysis large, arcuate in prolateral view, with two-pointed tips on opposite sides; embolus wide at base, slender and slightly curved distally; conductor triangular, concave at middle part; terminal apophysis about half the length of the bulb diameter, bifurcated distally.

Female (paratype IZCAS-Ar43085, Fig. 1A, B, E, F). Total length 3.40. Carapace 1.30 long, 1.15 wide. Abdomen 2.35 long, 2.05 wide. Clypeus 0.08 high. Eye sizes and interdistances: AME 0.10, ALE 0.08, PME 0.13, PLE 0.08, AME-AME 0.13, AME-ALE 0.15, PME-PME 0.15, PME-PLE 0.15, MOA length 0.33, anterior width 0.28, posterior width 0.30. Leg measurements: I 4.50 (1.30, 1.55, 1.20, 0.45), II 4.25 (1.25, 1.55, 1.05, 0.40), III 3.00 (0.95, 0.95, 0.75, 0.35), IV 4.15 (1.30, 1.40, 1.05, 0.40). Habitus similar to that of male, but white scaly spots more distinct.

Epigyne (Fig. 1A, B): about 1.65 times wider than long, lacking scape; copulatory openings slit-like, close to posterior margin; copulatory ducts almost as long as the spermathecae diameter, coiled about 360°; spermathecae spherical, touching each other.

Variation. Total length: ♂♂ 2.35-2.60; ♀♀ 3.15-3.40.

Distribution.

Known only from type localities (Yunnan, China).