Verrucachernes parvus ( Beier, 1930 ) Romero-Ortiz & Harvey, 2019

Romero-Ortiz, Catalina & Harvey, Mark S., 2019, The pseudoscorpion genus Verrucachernes (Pseudoscorpiones: Chernetidae) in the Indian region, Zootaxa 4568 (2), pp. 337-346 : 342-345

Verrucachernes parvus ( Beier, 1930) , comb. nov.

( Figs. 11–18 )

Withius parvus Beier 1930: 293 –294, fig. 5.

Metawithius parvus ( Beier): Beier 1932 : 201, fig. 206; Roewer 1937: 308.

Type material: INDIA: Kerala: holotype female, Travancore [ca. 8°30'N, 77°00'E] ( SMF1940 ) .

Diagnosis: Verrucachernes parvus differs from other species of the genus as follows: in general V. parvus is very small, e.g. the pedipalpal femur does not exceed 0.36 mm while in all other species it is larger than 0.41 mm; from V. oca by the coarsely granulate chela, which is smooth in V. oca , as well as its smaller size; from V. sublaevis and V. montigenus in its small size, e.g. the pedipalpal femur of these two species exceeds 0.50 mm, whereas it reaches 0.36 mm in V. parvus ; from V. indicus by the cheliceral seta bs being slightly denticulate (acuminate in P. indicus ); from V. congicus by the proportions of pedipalpal femur and patella which possess a slender femur and a stouter patella, e.g. femur 2.35 and patella 2.5 times longer than wide in V. congicus vs. femur 2.88 and patella 2.42 times longer than wide in V. parvus ; and from V. spinosus by the shape of the pedipalpal femur which is slender in V. parvus , and stouter in V. spinosus e.g. 2.88 vs. 2.18 times longer than wide.

Description (adult female): Colour: carapace and pedipalps white-yellow, tergites and coxal region pale yellow, and legs white-yellow.

Carapace ( Fig. 11 ): finely granulate; 1.43 × longer than broad; without eyes or eye-spots; with ca. 68 setae, including 38 in anterior section including 6 near anterior margin, 21 in median section and 9 setae in posterior section; with 2 furrows, just the anterior margin evident, posterior furrow weak, slightly closer to posterior margin than to anterior furrow; posterior margin straight.

Chelicera ( Fig. 12 ): with 5 setae on hand and 1 subdistal seta on movable finger; seta bs slightly denticulate, and ls, is and es acuminate; with 2 dorsal lyrifissures and 1 ventral lyrifissure; galea with rami bifid at the base and bifid in one top; rallum of 3 blades, anterior blade with several distal serrations, other blades smooth; lamina exterior present.

Pedipalp ( Fig. 13 ): trochanter, femur and patella coarsely granulate, chelal hand granulate on prolateral and retrolateral regions, nearly smooth elsewhere; patella with two small sub-basal lyrifissures; trochanter 1.66, femur 2.88, patella 2.42, chela (with pedicel) 3.62, chela (without pedicel) 4.43, hand 1.81 × longer than broad, movable finger 0.89 × longer than hand. Fixed chelal finger with 8 trichobothria, movable chelal finger with 4 trichobothria ( Fig. 14 ): eb and esb situated basally; est situated midway between et and esb; ib and ist situated basally; it situated closer to isb than to the tip of finger; isb slightly proximal to est; st situated much closer to t than to sb, and sb situated much closer to b than to st. Movable finger without pseudotactile setae. Venom apparatus only present in movable chelal finger, venom duct long, terminating in nodus ramosus near t. Chelal fingers teeth slightly blunt, basal teeth wider; fixed finger with ca. 52 teeth, without accessory teeth; movable finger with ca. 48 teeth, without accessory teeth; movable chelal finger with 2 retrolateral sense spots.

Coxal region: maxillae smooth, except for granulate anterior region; coxae smooth; manducatory process somewhat triangular, with 3 apical acuminate setae, 1 small sub-oral seta, and 18 additional setae; median maxillary lyrifissure rounded and situated submedially; posterior maxillary lyrifissure rounded. Chaetotaxy of coxae I–IV: 10: 13: 15: 28.

Legs ( Figs. 15, 16 ): junction between femora and patellae I and II slightly oblique to long axis ( Fig. 15 ); femur + patella of leg IV 4.06 × longer than broad; patella and tibia III and IV without ‘pseudotactile’ setae ( Fig. 16 ); tarsi III and IV with tactile seta, situated proximal, TS = 0.12; claws not modified; arolium slightly shorter than claws.

Abdomen: tergites I–XI and sternites IV–XI with medial suture line. Tergal chaetotaxy: 9: 10: 10: 12: 13: 13: 13: 13: 15: 13: 6: 2; all slightly clavate. Sternal chaetotaxy: 12: (2) 6 (2): (2) 8 (2): 11: 16: 24: 18: 17: 14: 8 (including 2 short tactile setae): 2. Sternite II with setae arranged in inverted U pattern ( Fig. 17 ). Pleural membrane finely longitudinally striate; without setae.

Genitalia: female: with a single rounded spermatheca on a long thin duct ( Fig. 18 ).

Dimensions (mm): holotype female: Body length 1.48. Carapace 0.520/0.365. Chelicera 0.150/0.095, movable finger length 0.150. Pedipalp: trochanter 0.225/0.135, femur 0.360/0.125, patella 0.375/0.155, chela (with pedicel) 0.760/0.210, chela (without pedicel) 0.720, hand (without pedicel) length 0.380, movable finger length 0.340. Leg I: femur 0.095/0.060, patella 0.150/0.070, tibia 0.160/0.055, tarsus 0.180/0.035. Leg IV: femur + patella 0.325/ 0.080, tibia 0.215/0.060, tarsus 0.215/0.045, TS = 0.120.

Remarks: Due to the age of the material and its preservation it was impossible to see the spermatheca using the standard clearing technique with lactic acid. We therefore cleared the specimen with an enzymatic digestion method ( Álvarez-Padilla & Hormiga 2007). The lack of a venom gland in the fixed chelal finger and the presence of a single large ovoid spermathecal receptaculum indicates that this species is not a member of the Withiidae but should be placed in Verrucachernes .

Figures

FIGURES 11–16. Ferrucachernes parvus (Beier, 1930), holotype female (SMF 1940): 11, carapace; 12, right chelicera, dorsal; 13, right pedipalp, dorsal; 14, left leg I; 15, left leg IV; 16, left chela, lateral. Scale lines: 0.2 mm (Figs. 11, 13–16); 0.1 mm (Fig. 12).

FIGURES 17–18. Ferrucachernes parvus (Beier, 1930), holotype female (SMF 1940): 17, genital sternites, ventral; 18, spermatheca, ventral. Scale lines = 0.1 mm.