Walckenaeria yunnanensis Xia, Zhang, Gao, Fei & Kim 2001

Song, Yanjing & Li, Shuqiang, 2011, Notes on Walckenaeria species (Araneae: Linyphiidae) from China, Revue suisse de Zoologie 118 (1), pp. 175-196 : 191-195

Walckenaeria yunnanensis Xia, Zhang, Gao, Fei & Kim 2001 Figs 11-13

Walckenaeria yunnanensis Xia et al., 2001: 163 , figs 8-13.

PARATYPES: JLU, without registration number; 1♂ 6♀; China, Yunnan Province, Dali City, Hudiequan Park (25.0ºN 102.7ºE); collected by J. Gao; collected on 26.07.1983.

DIAGNOSIS: This species has a well-developed lamella but no tailpiece on the male palp ( Figs 11A , 12D ). Palpal protegulum with 2 conspicuous membranous apophyses ( Fig. 11C ). Distal suprategular apophysis rather robust basally, with several deep grooves on the basal inner side. Base of the embolic division unique, with 2 membraneous conspicuous apophyses ( Fig. 12D ). Cymbium with a large retrobasal process ( Fig. 11D ). In addition, the shape of female capsule, where the copulatory ducts are embedded, is significantly different from known Walckenaeria species ( Fig. 13A, B, F ). Consequently W. yunnanensis can be very easily distinguished from other known Walckenaeria species.

RE- DESCRIPTION OF MALE PARATYPE: Carapace 1.24 long, 0.96 wide, orangebrown, raised into a large hump in the middle of the thoracic part, as well as 2 shallow sulci on both sides of the hump ( Fig. 12A, B ). Clypeus 0.22 high. AME diameter 0.08, ALE 0.07, PME 0.08, PLE 0.08, AME interdistance 0.56 times their diameter, AME-ALE interdistance 0.62 times ALE diameter, PME interdistance 1.04 times their diameter, PME-PLE interdistance 0.35 times PLE diameter. Sternum 0.64 long, 0.64 wide. Coxa IV interdistance 1.23 times their width. Chelicera with 5 promarginal and 4 retromarginal teeth ( Fig. 12C ). Leg I and leg III missing. Tm IV present. Number of dorsal spines on tibia of leg IV: 2-2-1-1 (see Xia et al., 2001). Leg measurements: I missing; II 3.76 (1.13, 0.28, 0.91, 0.88, 0.57); III missing; IV 3.62 (1.06, 0.28, 0.91, 0.91, 0.45).

Palp: Tibia short, with reduced distal apophysis ( Fig. 11 A-D); with 1 prolateral and 2 retrolateral trichobothria ( Fig. 11D ). Paracymbium with strongly sclerotized black base and blunt, slightly hooked apex ( Fig. 11D ). Cymbium with distinct retrobasal process ( Fig. 11D ). Tegulum distal to subtegulum in unexpanded palp ( Fig. 11A ). Protegulum well developed ( Fig. 11A, C ). Distal suprategular apophysis robust basally and gradually narrowing towards the tip ( Fig. 12E ), with several deep grooves on basal inner side. Embolic division: lamella large, widened distally ( Fig. 11C ); base of the embolic division membraneous, with 2 conspicuous apophyses distally ( Fig. 12D ); tailpiece absent ( Fig. 12D ); embolus broad, forming a long, wide coil ( Fig. 12D ).

RE- DESCRIPTION OF FEMALE PARATYPE. Carapace unmodified, similar to that of male in coloration. Carapace 1.19 long, 0.94 wide. Clypeus 0.16 high. AME diameter 0.08, ALE 0.11, PME 0.08, PLE 0.09, AME interdistance 0.32 times their diameter, AME-ALE interdistance 0.29 times ALE diameter, PME interdistance 0.81 times their diameter, PME-PLE interdistance 0.40 times PLE diameter. Sternum 0.61 long, 0.61 wide. Coxa IV interdistance 1.24 times their width. Chelicera with 4 promarginal and 5 retromarginal teeth. Tibia of leg I 8.17 times longer than deep. Tm I 0.58, Tm IV absent. Number of dorsal spines on tibia of leg IV: 2-2-1-1. Leg measurements: I 3.71 (1.09, 0.28, 0.92, 0.86, 0.56); II 3.41 (0.96, 0.28, 0.83, 0.79, 0.54); III 2.88 (0.86, 0.27, 0.62, 0.67, 0.46); IV 3.54 (1.03, 0.26, 0.88, 0.86, 0.52).

Dorsal plate totally exposed in ventral view ( Fig. 13D ) and a bit swollen in lateral view ( Fig. 13E ). Copulatory openings triangular, present between dorsal and ventral plate ( Fig. 13D ). Copulatory ducts enclosed in a slightly sclerotized spiral capsule ( Fig. 13A, B, F ). Spermathecae globular, separated from each other by a distance of more than 2 times their diameter ( Fig. 13G ). Fertilization ducts short, situated mesally ( Fig. 13B ).

VARIATION. 5♀ were measured. Carapace length varies from 0.91 to 1.22 and width 0.78 to 0.94.

REMARK. W. yunnanensis occupies an isolated position within Walckenaeria and may need to be separated into a distinct genus when similar new species are discovered.

DISTRIBUTION. Hudiequan in Yunnan Province.

Figures

FIG. 11 Walckenaeria yunnanensis; male paratype. (A) Distal part of left palp, ventral view. (B) Same, dorsal view. (C) Same, prolateral view. (D) Same, retrolateral view. Scale lines: 0.2 mm.

FIG. 12 Walckenaeria yunnanensis; male paratype. (A) Carapace, dorsal view. (B) Same, lateral view. (C) Left chelicera, posterior view. (D) Distal part of left palp, anterior view. (E) Distal part of suprategulum, retrolateral view. Scale lines: 0.2 mm.

FIG. 13 Walckenaeria yunnanensis; female paratype. (A) Vulva, ventral view. (B) Same, dorsal view. (C) Epigynum, dorsal view. (D) Same, ventral view. (E) Same, lateral view. (F) Vulva, anterior view. (G) Epigynum, posterior view. Scale lines: 0.2 mm.