Ideoblothrus pisolitus, Harvey & Edward, 2007

Harvey, Mark S. & Edward, Karen L., 2007, A review of the pseudoscorpion genus Ideoblothrus (Pseudoscorpiones, Syarinidae) from western and northern Australia, Journal of Natural History 41 (5 - 8), pp. 445-472 : 452-455

Ideoblothrus pisolitus sp. nov.

( Figures 3 , 8–21 )

Material examined

Holotype: „, Australia: Western Australia: Mesa B, 38.1 km W of Pannawonica , site MEBRC0021 ( T3-28 ), 21 ° 399360S, 115 ° 579200E, March to May 2005, litter trap, 30 m depth, M. Greenham, D. Kamien, and L. Mould ( WAM T 65783). Paratypes: Australia: Western Australia: 1♀, same data as holotype ( WAM T 68194); 2 „, same data as holotype ( WAM T 65786, T 65787); all from Mesa B, 37.9 km W of Pannawonica: 1♀, site MEBRC0016 ( T1-23 ), 21 ° 399490S, 115 ° 579270E, March to May 2005, litter trap, 10 m depth, M. Greenham, D. Kamien, and L. Mould ( WAM T 65785); one tritonymph, site MEBRC0015 ( T4-29 ), 21 ° 399520S, 115 ° 579270E, March to May 2005, litter trap, 40 m depth, M. Greenham, D. Kamien, and L. Mould ( WAM T 65784).

Etymology

The specific epithet refers to the presence of this species within Mesa B, which is formed from pisolite.

Diagnosis

Ideoblothrus pisolitus differs from all other species of the genus by the noticeably more slender pedipalpal patella and chela, which are 2.22–2.26 („), 2.08–2.27 (♀) and chela (with pedicel) 3.36–3.47 („), 3.07 (♀) times longer than broad, respectively. In addition, I. pisolitus has only four setae in the intermediate row of the carapace, which are situated near the lateral margins of the carapace.

Description

Adults. Colour: carapace and pedipalps reddish brown, abdomen and legs pale tan.

Chelicera ( Figure 17 ): five setae on hand, all setae acuminate, is, ls, sbs, and bs long, es very short; movable finger with one sub-distal seta; fixed finger with ca eight teeth; movable finger with ca seven teeth; with two dorsal lyrifissures and one ventral lyrifissure; galea straight and extends past tip of finger but not extending to tip of galeal seta; flagellum ( Figure 18 ) of five blades, distal blade broadened and finely denticulate; serrula exterior with 23–25 („), 25–27 (♀) blades.

Pedipalp ( Figure 9 ): internal margins of trochanter, femur, patella, and chela sparsely granulate; setae on internal margins very long and acicular; trochanter without tubercles; trochanter 1.82–2.04 („), 1.79–1.99 (♀), femur 3.09–3.24 („), 2.95–3.07 (♀), patella 2.22– 2.26 („), 2.08–2.27 (♀), chela (with pedicel) 3.36–3.47 („), 3.07 (♀), chela (without pedicel) 3.13–3.25 („), 2.86–2.90 (♀), hand 1.44–1.60 („), 1.59–1.61 (♀) times longer than broad; movable finger 1.04–1.16 („), 0.79–0.84 (♀) times longer than hand. Femur without tactile setae; without basal projection. Patella with two lyrifissures situated dorsally near pedicel. Fixed chelal finger with eight trichobothria, movable chelal finger with four trichobothria ( Figure 10 ): eb and esb at base of finger, isb situated near ib; est situated near ist; it distal to est; et sub-distal; microsetae (chemosensory setae) absent on both fingers; trichobothria b of movable finger situated basally; sb, st, and t situated medially, close to each other; t slightly shortened, lanceolate, and bent backward. Venom apparatus present only in fixed chelal finger, venom duct very short, nodus ramosus inflated. Chelal teeth of both fingers ( Figure 10 ) rounded; fixed finger with 40 („), 38 (♀) teeth; movable finger with 50 („), 52 (♀) teeth; accessory teeth absent. External and internal chelal condyles small and rounded.

Cephalothorax: carapace ( Figure 8 ) 1.34–1.44 („), 1.35–1.36 (♀) times longer than broad; sub-rectangular; without any traces of eyes; epistome present; with 21 setae arranged 4: 4: 4: 4: 5; without furrows; with five pairs of small lyrifissures, first and second pairs placed near anterior margin, third pair placed sub-medially, fourth and fifth pairs placed near setae on posterior row. Manducatory process ( Figure 14 ) with one long distal and one long sub-distal seta, without sub-oral seta; remainder of maxilla with eight setae. Chaetotaxy of coxae I–IV: 5–6: 5: 3–4: 6 („), 6: 5: 3–4: 6 (♀). Posterior section of coxae II slightly overlapping anterior section of coxae III ( Figure 14 ).

Abdomen: pleural membrane granulo-striate near cephalothorax, remainder longitudinally striate ( Figures 14–16 ), without setae. Tergites and sternites undivided. Tergal chaetotaxy: holotype „, 6: 7: 7: 9: 8: 8: 9: 9: 9: 7: 4: 2; paratype ♀ ( WAM T 68194), 6: 7: 8: 9: 9: 9: 9: 9: 9: 7: 7: 2; setae uniseriate and acuminate. Sternal chaetotaxy: holotype „, 9: (3) 10 [3+3] (2): (2) 8 (2): 10: 11: 11: 11: 10: 10: 4: 2; paratype ♀ ( WAM T 68194), 8: (3) 6 (3): (2) 8 (2): 11: 12: 11: 11: 11: 10: 4: 2; setae on sternite II of ♀ small; setae uniseriate and acuminate; without median glandular setae; anus not surrounded by sternite XI .

Genitalia: male genitalia with small rounded ejaculatory canal atrium; moderately sized lateral genital sacs and an undivided, enlarged median genital sac ( Figure 19 ); male internal genital setae arranged in two triangular groups of three; pair of setae surrounding an anteromedian notch of the posterior genital operculum; single, ovoid median genital sac. Female genitalia ( Figure 21 ) with single, broad median cribriform plate, and one pair of slender lateral median cribriform plates.

Legs ( Figures 12, 13 ): femora I and II longer than patellae I and II; femora I and II with one transverse lyrifissure situated sub-distally; femur + patella of leg IV 3.74 („), 3.88 (♀) times longer than broad; legs III and IV with articulation between femur and patella segments slightly oblique; tibiae III and IV with medial tactile seta; metatarsi III and IV with sub-basal tactile seta; diplotarsate, all legs with tarsus longer than metatarsus; subterminal tarsal setae distally serrate; arolia same length as claws, not divided; claws simple.

Dimensions (mm) of „ holotype WAM T 65783 (with other males in parentheses where relevant): body length 2.25 (1.49–1.72). Pedipalps : trochanter 0.230 / 0.118 (0.211–0.233/0.114–0.116) , femur 0.429 / 0.134 (0.408–0.424/0.131– 0.132), patella 0.430 / 0.190 (0.392–0.398/0.177–0.179), chela (with pedicel) 0.739 / 0.220 (0.720–0.733/0.211–0.214), chela (without pedicel) 0.688 (0.670 –0.685), hand length 0.352 (0.309 –0.333), movable finger length 0.365 (0.349 –0.357). Chelicera 0.243 / 0.100 (0.240–0.256/0.102–0.104) , movable finger length 0.179 (0.177 –0.192). Carapace 0.496 / 0.371 (0.467–0.494/0.333–0.342). Leg I: femur 0.170 / 0.079, patella 0.150 / 0.074, tibia 0.227 / 0.049, metatarsus 0.086 / 0.035, tarsus 0.154 / 0.031. Leg IV: femur + patella 0.389 / 0.104, tibia 0.321 / 0.058, metatarsus 0.096 / 0.045, tarsus 0.148 / 0.039.

Dimensions (mm) of ♀ paratype WAM T 68194 (♀ paratype WAM T 65785): body length 2.98 (2.45). Pedipalps : trochanter 0.321 / 0.179 (0.339 / 0.170) , femur 0.567 / 0.192 (0.590 / 0.192), patella 0.611 / 0.269 (0.571 / 0.275), chela (with pedicel) 1.027 / 0.335 (1.059 / 0.345), chela (without pedicel) 0.957 (1.000), hand length 0.531 (0.554), movable finger length 0.446 (0.436). Chelicera 0.333 / 0.156 (0.340 / 0.150) , movable finger length 0.260 (0.261). Carapace 0.670 / 0.493 (0.674 / 0.499). Leg I: femur 0.234 / 0.104, patella 0.191 / 0.094, tibia 0.318 / 0.064, metatarsus 0.110 / 0.043, tarsus 0.182 / 0.033. Leg IV: femur + patella 0.540 / 0.139, tibia 0.447 / 0.081, metatarsus 0.118 / 0.054, tarsus 0.205 / 0.045.

Tritonymph. Morphology generally as in adults.

Colour: all sclerotised portions pale red-orange, rest of body pale yellow-brown.

Chelicera: with five setae on hand, all setae acuminate; movable finger one sub-distal seta; galea straight and extends past tip of finger but not extending to tip of galeal seta; flagellum of five blades, distal blade broadened and finely denticulate; serrula exterior with ca 22 blades.

Pedipalp: internal margins of femur, patella, and chela with light granulations, setae on internal margins very long and acicular; femur without tactile setae; trochanter 2.04, femur 3.06, patella 2.19, chela (with pedicel) 3.17, chela (without pedicel) 2.94, hand 1.58 times longer than broad, movable finger 0.91 times longer than hand. Fixed chelal finger with seven trichobothria, movable chelal finger with three trichobothria ( Figure 11 ): isb and sb absent; eb and esb situated at base of fixed finger; ib situated on dorso-distal surface of hand; ist and est situated close together, et situated sub-distally; b situated sub-basally; st and t situated sub-distally, t lanceolate, slightly shortened, and bent backward. Venom apparatus only present in fixed chelal finger, venom duct very short, nodus ramosus inflated. Chelal teeth: fixed finger with ca 29 rounded teeth; movable finger with ca 38 rounded teeth.

Cephalothorax: carapace 1.38 times longer than broad; without eyes; epistome absent; with 23 setae, arranged 4: 4: 4: 4: 2: 5.

Abdomen: pleural membrane granulo-striate near cephalothorax, remainder longitudinally striate, without setae. Tergites and sternites undivided. Tergal chaetotaxy: 6: 7: 6: 8: 8: 8: 9: 9: 8: 7: 6: 2. Sternal chaetotaxy: 0: (2) 4 (2): (2) 7 (2): 9: 9: 9: 8: 7: 7: 4: 2.

Legs: femur I longer than patella I; metatarsi and tarsi not fused; arolium same length as claws, not divided.

Dimensions (mm) of tritonymph paratype WAM T 65784: body length 1.750. Carapace 0.481 / 0.349. Pedipalps: trochanter 0.226 / 0.111, femur 0.398 / 0.130, patella 0.372 / 0.170, chela (with pedicel) 0.669 / 0.211, chela (without pedicel) 0.621, hand length 0.333, movable finger length 0.304 .

Remarks

Ideoblothrus pisolitus has only been found within one iron-bearing pisolite mesa, approximately 173 ha in area, in the Pannawonica region of Western Australia. Three males, two females, and one tritonymph were collected from three boreholes using leaflitter baited traps placed at depths of 10– 40 m.

Figures

Figures 3, 4. (3) Ideoblothrus pisolitus sp. nov., paratype ♀ (WAM T65785). (4) I. nesotymbus sp. nov., paratype ♀ (WAM T75213).

Figures 8–13. Ideoblothrus pisolitus sp. nov., holotype „ unless otherwise stated. (8) Carapace. (9) Right pedipalp, dorsal. (10) Left chela, lateral. (11) Left chela, lateral, paratype tritonymph (WAM T65784). (12) Leg I. (13) Leg IV. Scale bars: 0.2 mm (8, 10–13); 0.5 mm (9).

Figures 14–18. Ideoblothrus pisolitus sp. nov., holotype „. (14) Coxal region, ventral. (15) Detail of pleural membrane, near pedipalpal coxae. (16) Detail of pleural membrane, near sternite IV. (17) Left chelicera, dorsal. (18) Flagellum. Scale bars: 0.2 mm (14); 0.1 mm (15–18).

Figures 19–21. Ideoblothrus pisolitus sp. nov., holotype „ unless otherwise stated. (19) Male genitalia, ventral. (20) Male genital opercula, ventral. (21) Female genitalia, paratype ♀ (WAM T68194). Scale bars: 0.1 mm.