Walckenaeria asymmetrica, Song & Li & P. & R., 2011

Song, Yanjing & Li, Shuqiang, 2011, Notes on Walckenaeria species (Araneae: Linyphiidae) from China, Revue suisse de Zoologie 118 (1), pp. 175-196 : 176-180

Walckenaeria asymmetrica sp. n.

Figs 1-2

HOLOTYPE: IZCAS, without registration number; ♂; China, Henan Province, Nanyang City, Baotianman National Nature Reserve (33.32ºN 112.20ºE); collected by Q. Wang and Y. Lin; collected on 12.11.2005.

PARATYPES: IZCAS (1♀) and MHNG (1♀ 1♂), without registration number ; same data as for holotype.

DIAGNOSIS: The new species is similar to W. chiyokoae Saito, 1988 , but the male can be distinguished by the shape of the prolateral apophysis of the palpal tibia, which is composed of 4 or 3 branches in W. asymmetrica ( Fig. 1E, G ), but only 2 in W. chiyokoae ; by the strongly sclerotized dentiform retrolateral apophysis of the palpal tibia in W. asymmetrica ( Fig. 1G ) versus a slightly sclerotized rectangular apophysis in W. chiyokoae ; by a long and strongly curved tailpiece in W. chiyokoae , but a shorter and more straight one in W. asymmetrica ( Fig. 1A, C ); by the different ratio of the length of the embolus to the length of the cymbium (about 3.9 in W. asymmetrica and 4.9 in W. chiyokoae ). The female is extremely similar to that of W. chiyokoae , except for the relatively straight and undeveloped anterior part of the copulatory ducts, and females cannot be safely identified unless collected together with males.

DESCRIPTION OF MALE HOLOTYPE: Total length 2.14. Carapace 1.05 long, 0.78 wide, light orange. Head raised into a lobe carrying posterior median eyes ( Fig. 2B ); a conspicuous sulcus running back from behind PLE and containing a small pit anteriorly ( Fig. 2B ). Clypeus 0.21 high, with a patch of hairs in the ocular area and on the clypeus ( Fig. 2B ). AME diameter 0.05, ALE 0.08, PME 0.10, PLE 0.08, AME interdistance 0.31 times their diameter, AME-ALE interdistance 0.67 times ALE diameter, PME interdistance 1.06 times their diameter, PME-PLE interdistance 2.52 times PLE diameter. Sternum 0.59 long, 0.57 wide. Coxa IV interdistance 1.19 times their width. Chelicera light orange, with 4 promarginal and 2 retromarginal teeth ( Fig. 2C ). Tibia of leg I 8.94 times longer than deep. Tm I 0.53, Tm IV present. Tibiae of all legs with very short spines and their length almost half of the width of tibiae. Number of dorsal spines on tibiae of legs I-IV: 1-1-1-1. Leg measurements: I 3.56 (1.02, 0.30, 0.95, 0.78, 0.51); II 3.38 (0.96, 0.29, 0.89, 0.76, 0.49); III 2.84 (0.81, 0.29, 0.68, 0.66, 0.41); IV 3.70 (1.03, 0.30, 0.98, 0.91, 0.49).

Palp: Patella a bit shorter than femur ( Fig. 1F ). Tibia short, armed with 1 strongly sclerotized, dentiform retrolateral apophysis and 1 large prolateral apophysis with scaly inner surface and distal margin with 3 (right male palp) or 4 (left male palp) branches; with 1 prolateral and 2 retrolateral trichobothria ( Fig. 1D ). Paracymbium Cshaped, basal part folded downwards ( Fig. 1B ). Tegulum distal to subtegulum in unexpanded palp ( Fig. 1B ). Protegulum with some unconspicuous papillae ( Fig. 1A, B ). Distal suprategular apophysis well developed, ending in a cavity accommodating distal one-sixth of long coiled embolus; with a broad groove retrolaterally and bearing a small tooth on the upper side ( Fig. 1B, C ). Embolic division very simple. Embolus very long (about 1.5 cm), with a narrow membrane along inner margin. Tailpiece short, twisted clockwise in prolateral view, ending in a lobe in ventral view ( Fig. 1A ).

DESCRIPTION OF FEMALE PARATYPE (IZCAS): Carapace ( Fig. 2A ) unmodified, similar to that of male in coloration. Total length 2.27. Carapace 0.94 long, 0.78 wide. Clypeus 0.18 high. AME diameter 0.06, ALE 0.09, PME 0.08, PLE 0.08, AME interdistance 0.26 times their diameter, AME-ALE interdistance 0.38 times ALE diameter, PME interdistance 0.36 times their diameter, PME-PLE interdistance 0.42 times PLE diameter. Sternum 0.59 long, 0.59 wide. Coxa IV interdistance 0.77 times their width. Chelicera with 4 promarginal and 2 retromarginal teeth. Tibia of leg I 6.52 times longer than deep. Tm I 0.52, Tm IV present. Length of spine on tibiae of all legs almost equal to width of tibiae. Number of dorsal spines on tibiae of legs I-IV: 1-1-1-1. Leg measurements: I 3.29 (0.98, 0.31, 0.86, 0.69, 0.46); II 3.19 (0.96, 0.30, 0.81, 0.68, 0.45); III 2.76 (0.82, 0.27, 0.68, 0.61, 0.38); IV 3.59 (1.04, 0.27, 0.95, 0.86, 0.46).

Surface of epigynum almost transparent. Posterior margin of dorsal plate lipshaped and totally exposed in ventral view ( Fig. 2D ). Copulatory openings long, curved, situated at the junction of dorsal plate and ventral plate ( Fig. 2D, E ). Copulatory ducts enclosed in a strongly sclerotized and rather complicated capsule, forming a pair of large loops on ventral side ( Fig. 2F ). Spermathecae globular, separated from each other by 3 times their diameter ( Fig. 2F, G ). Fertilization ducts very short, mesally situated ( Fig. 2G ).

ETYMOLOGY: The specific name is an adjective of the Greek noun symmetria (= symmetry), combined with the alpha privativum, and refers to asymmetrical male palps of the holotype (IZCAS) and paratype (MHNG). The distal margin of the prolateral tibial apophysis of the left palps of both specimens has 4 branches, but the right palp only 3 branches.

DISTRIBUTION: Only known from Baotianman National Nature Reserve in the Henan Province, China.

HABITAT: The spiders were found under dead leaves on the ground.

Figures

FIG. 1 Walckenaeria asymmetrica sp. n.; male holotype. (A) Distal part of left palp, prolateral view. (B) Same, retrolateral view (arrow indicating small triangular apophysis on upper margin of suprategulum). (C) Same, ventral view. (D) Tibia of left palp, dorsal view. (E) Distal part of tibia of right palp, lateral view. (F) Patella and femur of left palp, retrolateral view. (G) Tibia of left palp, lateral view. Scale lines: 0.1 mm.

FIG. 2 Walckenaeria asymmetrica sp. n.; male holotype (B, C) and female paratype (A, D-G). (A) Carapace, dorsal view. (B) Same, lateral view. (C) Left chelicera, posterior view. (D) Epigynum, ventral view. (E) Same, posterior view. (F) Vulva, ventral view. (G) Same, dorsal view. Scale lines: A, B=0.2 mm, C-G=0.1 mm.