Samarangopus dilatare Qian, sp. n.

Samarangopus dilatare Qian sp. n.

(Figure 2)

Type material. Holotype. ad.9 (female), Sanqingshan, Jiangxi, 5 July 2012, leg. Qian & Chu.

Paratypes. ad.9 (female), Sanqingshan, Jiangxi, 7 July 2012, leg. Qian & Chu.

ad.9 (female), Sanqingshan, Jiangxi, 6 July 2012, leg. Qian & Chu.

ad.9 (female), Sanqingshan, Jiangxi, 8 July 2012, leg. Qian & Chu.

Etymology. From Latin dilatare = widened, inflated (referring to the shape of the lateral margins of the branches of the anal plate).

Diagnosis. Samarangopus dilatare sp. n., is closely related to the seven species previously described in this genus, S. poculifer and S. umbonifer Scheller 1995 from Chiang Mai province, Thailand; S. papuensis Scheller 1996 from Papua New Guinea; S. proekes Scheller 2001 from Sabah; S. campanulatus Scheller 2004 from Kien Giang province, Vietnam; S. tuberosus Scheller 2007 from Labrador Hill, Singapore; S. amplissimus Scheller 2009 from Sumatra, Padang, Kotomalintang, Indonesia. The new species can be distinguished from them by comparing the shape of the tergal setae. a 1 cylindrical, blunt, straight, curved inwards, distal part granular; a 2 similar to a 1 but clavate and converging; a 3 tapering, diverging, distal part granular; st lanceolate, glabrous in S. pucolifer; a 1 cylindrical, curved inwards, glabrous; a 2 clavate, glabrous; a 3 tapering, pointed, with oblique pubescence; st clavate, glabrous, curved inwards in S. umbonifer; a 1, a 2, a 3 cylindrical, blunt, with pubescence, st lanceolate, glabrous in S. papuensis; a 1 and a 2 clavate, with very short pubescence distally, diverging; a 3 subcylindrical, glabrous, curved inwards and somewhat diverging in S. proekes; a 1 and a 2 somewhat clavate, the former cured inwards and the latter almost straight; a 3 straight, cylindrical, somewhat tapering, diverging; st straight, lanceolate in S. campanulatus; a 1, a 2, a 3 glabrous, straight, cylindrical; st lanceolate, curved inwards, directed posteriorly in S. tuberosus; a 1 thin tapering pointed, only faintly pubescent, a 2, a 3 thick clavate, with dense erect pubescence, st lanceolate, narrowing distally, shortly pubescent in S. amplissimus. In contrast, a 1 widening, a 2, a 3 cylindrical, blunt, glabrous, st thin, tapering, glabrous in the new species. Another good distinguishing character is the shape of the anal plate. Lateral margins with a pair of thin, diverging, somewhat clavate, striated, curved branches in S. poculifer; posterior branches cut at right angles to length, with submedian appendages longer than width of branch in S. umbonifer; lateral margins with a pair of thin, diverging, cylindrical, striate branches in S. papuensis; broadest part with evenly rounded margins, two thin, cylindrical, blunt, appendages protrude obliquely backwards in S. proekes; broadest part forming indistinct posterolateral corners, from there two short, thin, cylindrical, blunt, pubescent appendages protruding obliquely backwards in S. campanulatus; later margins convex anteriorly, concave posteriorly, V-shaped incision into two tube-like branches in S. tuberosus; lateral margins without branches in S. amplissimus. In contrast, the lateral margins with a pair of thin, diverging, cylindrical, distal part faintly inflated, glabrous branches in Samarangopus dilatare sp. n.

Description. Length. 1.33 (- 1.50) mm.

Antennae. Chaetotaxy of segments 1– 4: 2/2/2/3. All setae but p ’ thin, cylindrical, annulated; p ’ pointed, annulated. Relative lengths of setae on segment 4: p = 100, p ' = (130 -) 133, p " = 90 (- 93). Tergal branch t fusiform, 2.9 (- 3.1) times as wide as greatest diameter and 1.0 (- 1.1) times as long as sternal branch s. That branch (1.9 -) 2.8 times as long as greatest diameter, anterodistal corner distinctly truncate. Seta q similar to setae of segment 4, almost straight, 0.66 of the length of s. Relative lengths of flagella (base segments included) and base segments: F 1 = 100, bs 1 = 16 (- 18), F 2 = (52 -) 53 (- 58), bs 2 = 10(- 11), F 3 = (78 -) 90 (- 100), bs 3 = 15 (- 18). F 1 (3.5 -) 3.9 times as long as t, F 2 and F 3 (1.9 -) 2.0 and (2.9 -) 3.4 times as long as sternal branch s. Calyces of F 1 helmetshaped, subhemispherical on F 2 and F 3. Globulus g with conical stalk, length of g (1.7 -) 1.9 times as long as greatest diameter, the latter 0.5 (- 0.6) of greatest diameter of t. Eight bracts, capsule subspherical. Stalk of capsule in paratypes with one lamella (similar to those on flagella).

Trunk. Setae of collum segment similar, furcate, branches thin, tapering, pointed, glabrous. Process glabrous, distinctly concave laterally, small anterior incision. Appendages glabrous, caps flat. Tergite densely covered with protuberances densely. Three main types of protuberances:

1. large, stalked, with at least basal part of lateral sides turned upward, larger ones hollow and distally pointed; these protuberances on anterior margin of tergite I and on lateral margins of I–VI; 2. smaller fungiform structures with transparent hat and subcylindrical foot, a pore leading from top into stalk; 3. many small endocuticular rods or canals. Number of marginal protuberances: I, 36; II, 1 small- T 1-1 small-9; III, 1 small-9- T 2-l small-6; IV,12- T 3-5; V, 13- T 4-4; VI, 6- T 5-l.. Bothriotricha. All with thin axes and short almost erect pubescence, T 1, T 2, T 4 and T 5 with distal part curled, T 3 almost straight with thicker axis and distal 1/4 flat, ovoid, glabrous. Relative lengths of bothriotricha: T 1 = 100, T 2 = 101(- 103), T 3 = (66 -) 75, T 4 = 85 (- 92), T 5 = 105 (- 108).

Legs. All legs 5-segmented. Setae on coxa and trochanter of leg 9 furcate, both branches of similar length, thin, cylindrical, glabrous. On more anterior legs these setae with rudimentary secondary branches; seta on coxa of leg 2 in male not deviating. Tarsi tapering, those of leg 9 1.8 (- 1.9) times as long as greatest diameter; tergal setae, pointed, glabrous, proximal seta 0.36 of the length of tarsus and 1.3 times as long as distal seta. No proximal seta on tarsus of leg 1. All legs with large main claw, those of leg 9 0.7 times as long as tarsi.

Pygidium. Tergum. Posterior margin with two large triangular lobes projecting backward behind setae a 3, lobes as long as a 2, the latter inserted near inner base. Setae a 1, a 2 and a 3 curved inward, a 2 also converging and distally clavate, a 1 and a 3 cylindrical, almost glabrous, st somewhat converging, lanceolate, glabrous. Relative lengths of setae: a 1 = 10, a 2 = 7.5, a 3 = 13.5 (- 15), st = 13.

Sternum. Posterior margin with shallow indentation, two very low bulges just below anal plate. Setae thin, tapering, pointed, only b 3 striate most distally; their relative lengths (pygidial a 1 = 10): b 1 = 68.5, b 2 = (24 -) 26.5, b 3 = (14 -) 17. b 1 1.4 times as long as interdistance, b 2 (0.8 -) 0.9 of distance b 1 – b 2, b 3 0.51 of interdistance.

Anal plate 1.9 times as long as broad, strongly tapering posteriorly; lateral margins with a pair of thin, diverging, cylindrical, distal part faintly inflated, glabrous branches which are 0.38 of the length of plate; posterior third divided lengthways by a narrow U shaped incision into two tapering appendages with straight margins, ends of appendages with thorn like prolongation of inner margins; posterior appendages with stalked bladders which are pointed distally and covered with a short but dense granule; bladders 2.5 times longer than wide, 0.48 of the length of plate.

FIGURE 2. Samarangopus dilatare Qian sp. n. holotype (female). A, right antenna, tergal view. B, pygidium, left part, sternal view. C, leg 9. D, T 3 (below), T 5. E, anteriomedian margin of tergite I with three large wedge-shaped protuberances, tergal view. F, fungiform protuberance, lateral view. G, right anteriolateral corner of tergite II with large protuberances. H, Collum segment, median and right part, sternal view.