Ideoblothrus milikapiti, 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 : 468-470

Ideoblothrus milikapiti sp. nov.

( Figures 42–45 )

Material examined

Holotype: „, Australia: Northern Territory: Milikapiti, Melville Island , 11 ° 259S, 130 ° 409E, 21 December 1994, D. Hyder ( WAM T 70782). Paratype: Australia: Northern Territory: 1 „, same data as holotype ( WAM T 71390).

Etymology

The specific epithet is a noun in apposition taken from the type locality, Milikapiti on Melville Island.

Diagnosis

Ideoblothrus milikapiti is one of the smallest in the genus [e.g. pedipalpal patella length 0.20– 0.21 mm („)] and is much smaller than most other Australasian species, including I. pisolitus , I. nesotymbus , I. descartes , I. aeesti , I. papillon , I. aeoodi , I. ceylonicus , I. pugil , and I. pugil robustus (all with pedipalpal patella greater than 0.30 mm). It is of similar size to I. bipectinatus from New Guinea [e.g. pedipalpal patella 0.21 mm („)], and I. palauensis from Palau [e.g. pedipalpal patella 0.22 mm („)]. It differs from I. bipectinatus by the shape of the pedipalpal chela (with pedicel) which is 2.84–2.94 („) times longer than broad, compared with 2.25 („) in I. bipectinatus . It differs from I. palauensis in the position of trichobothrium ist and it which are adjacent to each other in I. palauensis but it is slightly distal to ist in I. milikapiti .

Description

Adult male. Colour: pedipalps and chelicera red orange, carapace slightly orange, rest of body pale yellow.

Chelicera: 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 seven teeth; movable finger with ca six teeth; with two dorsal lyrifissures and one ventral lyrifissure; galea short, only very slightly curved and not extending to tip of galeal seta; flagellum of five blades, distal blade broadened and finely denticulate; serrula exterior with ca 17–18 blades.

Pedipalp ( Figure 43 ): mostly smooth, with only the internal margins of femur, patella, and chela with fine granulations; setae on internal margins long and acicular; trochanter without tubercles; trochanter 1.74–1.93, femur 2.46–2.48, patella 1.86–1.89, chela (with pedicel) 2.84–2.97, chela (without pedicel) 2.70–2.75, hand 1.35–1.38 times longer than broad, movable finger 1.03–1.04 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 44 ): eb, esb, isb, and ib forming an arc on baso-lateral margin of hand; isb situated slightly distally to ib; ist, est, and it situated close together; et sub-distal; two small lanceolate setae present on fixed chelal finger, one situated near esb and another between isb and est; microsetae (chemosensory setae) absent on both fingers; trichobothrium b of movable finger situated sub-basally; sb, st, and t situated medially, close to each other, st and t nearly touching and separated by less than one areolar diameter; t lanceolate, slightly shortened, and bent backward. Venom apparatus present only in fixed chelal finger, venom duct very short, nodus ramosus inflated. Chelal teeth of both fingers with flattened edges; fixed finger with 20–21 teeth; movable finger with ca 27–29 teeth; accessory teeth absent. External and internal chelal condyles small and rounded.

Cephalothorax: carapace ( Figure 42 ) 1.13–1.28 times longer than broad; sub-rectangular; without any traces of eyes; epistome small; with 22 setae arranged 4: 4: 4: 4: 6; without furrows; with three pairs of small lyrifissures, first and second pairs placed near anterior margin, and third pair placed near edge of posterior row. Manducatory process with one long distal and one long sub-distal seta, without sub-oral seta; remainder of maxilla with seven setae ( Figure 45 ). Chaetotaxy of coxae I–IV: 4–5: 4: 4: 6. Posterior section of coxae II slightly overlapping anterior section of coxae III ( Figure 45 ).

Abdomen: pleural membrane granulo-striate near cephalothorax, remainder longitudinally striate, without setae. Tergites and sternites undivided. Tergal chaetotaxy: 6: 6–7: 7–8: 9: 9: 9: 9: 9: 9: 7: 7: 2; setae uniseriate and acuminate. Sternal chaetotaxy: 6–8: (2) 10 [3+3] (2): (2) 7–8 (2): 10–11: 11: 11: 11: 11: 10–11: 4: 2; setae uniseriate and acuminate, without medial glandular setae; anus not surrounded by sternite XI.

Genitalia: male genitalia, as far as can be discerned, identical to I. pisolitus , apart from a smaller medial genital sac; pair of setae on edge of sternite III surrounding the anteromedian notch of the posterior genital operculum; internal genital glandular setae arranged in two triangular groups of 3.

Legs: 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 3.00 times longer than broad; legs III and IV with articulation between femur and patella segments slightly oblique; tibiae III and IV with one medial and one sub-distal tactile seta; metatarsi III and IV with medial tactile seta; diplotarsate, all legs with tarsus longer than metatarsus; subterminal tarsal setae not distally serrate; arolia slightly shorter than claws, not divided; claws simple.

Dimensions (mm) of „ holotype WAM T 70782 (with „ paratype WAM T 71390 in parentheses, where applicable): body length 1.04 (1.26). Pedipalps: trochanter 0.125 / 0.072 (0.129 / 0.067), femur 0.221 / 0.089 (0.221 / 0.090), patella 0.201 / 0.108 (0.212 / 0.112), chela (with pedicel) 0.371 / 0.125 (0.381 / 0.134), chela (without pedicel) 0.344 (0.362), hand length 0.172 (0.181), movable finger length 0.178 (0.187). Chelicera 0.155 / 0.077 (0.152 / 0.075), movable finger length 0.115 (0.112). Carapace 0.285 / 0.253 (0.285 / 0.222). Leg I: femur 0.088 / 0.051 , patella 0.074 / 0.048, tibia 0.104 / 0.032, metatarsus 0.042 / 0.026, tarsus 0.071 / 0.021. Leg IV: femur + patella 0.186 / 0.062 , tibia 0.141 / 0.042, metatarsus 0.053 / 0.030, tarsus 0.080 / 0.027.

Remarks

Ideoblothrus milkapiti is known from a single location on Melville Island in the Northern Territory ( Figure 1 ).

Figures

Figures 42–45. Ideoblothrus milikapiti sp. nov., holotype „. (42) Carapace. (43) Right pedipalp, dorsal. (44) Left chela, lateral. (45) Coxal region, ventral. Scale bars: 0.1 mm (42, 44, 45); 0.2 mm (43).

Figures 1, 2. Known distributions of Ideoblothrus species in Western Australia and Northern Territory.