Hesperentomon bolense, Qian & Bu & Luan, 2018

Qian, Chang-Yuan, Bu, Yun & Luan, Yun-Xia, 2018, DNA barcoding and an updated key to the genus Hesperentomon (Protura: Acerentomata: Hesperentomidae), with a new species from Northwest China, Zootaxa 4462 (4), pp. 523-534 : 525-529

Hesperentomon bolense sp. n.

Figs. 1‒27

Material examined. Holotype ♂ (No. BL 1705D), Northwest China, Xinjiang Uygur Autonomous Region, Bole, Bortala Mongol Autonomous Prefecture , extracted from a soil sample from dense birch forest, Hariturege National Forest Park , 44°57' N 81°54' E, elev. 599 m, 31‒VIII‒2016, coll. C.Y. Qian, C .W. Huang, A.M. Liu. Paratypes: 6 ♀ (nos. BL1701D, BL1702D, BL1703D, BL1704D, BL1707D, BL1708D), 1 ♂ (no. BL1706D), same data as holotype .

Diagnosis. Hesperentomon bolense sp. n. is characterized by having foretarsal sensillum b clearly shorter than c, and sensillum c broader than the other foretarsal sensilla; 18 posterior setae on mesonotum, 16 posterior setae on metanotum; 12 posterior setae on urotergites II‒VI (P1a and P2a absent), 8 posterior setae on urosternites IV‒VI (Pc absent), absence of setae P2a on urotergite VII; 4 and 6 anterior setae on mesosternum and metasternum respectively; 7‒9 teeth on comb.

Description. Adult body length 1,277‒1,322 µm (n = 8), body light brown, foretarsus darker ( Fig. 1).

Head oblong, length 145‒155 µm, width 91‒102 µm. Dorsal setae long, other setae short. Setae sd4, d6 and sd6 present. Seta d 6 14‒15 µm, d7 9 µm in length. Paired pores cp, ip and op present, pore fp absent. Pseudoculus pear-shaped, with short posterior extension, length 15.6‒16.7 µm, width 6.7‒8.9 µm. PR = 9.3 ( Figs. 2, 11). Canal of maxillary gland with sausage-like calyx, posterior dilation approximately equal to length of calyx ( Fig. 12). CF = 10.6‒11.4. Maxillary palpus with two tapering sensilla, dorsal sensillum (8‒9 µm) distinctly longer than lateral sensillum (5‒6 µm) ( Fig. 13). Labial palpus well developed, without basal sensillum ( Fig. 14).

Foretarsus length 114 µm, claw length 25 µm, TR = 3.5; empodium length 9.1 µm, EU = 0.36. Dorsal sensillum t1 slender, pointed; t2 slender, pointed, longer than t1; t3 shorter than t1, blunt, slight widened; BS = 0.93; exterior sensilla filiform, c, d, e and g approximately parallel-sided, a slight broadened, pointed, shorter than t1; b slight broadened, blunt, same length as a, reaching base of d; c long and robust, broader than other sensilla; d 1.3 times longer than a, based nearer to e than to c; e robust, same length as d; f and g robust, f short, g same length as e. Interior sensillum a' blunt; b'-1 slender, pointed; b'-2 robust, shorter than b'-1; c'-2 reaching base of claw; c'-1 blunt and short. Relative length of sensilla: c'-1 <(f = b'-2) <(a = a' = t3 = b) <(b'-1 = c'-2) <(d = g = t1= e) <(c = t2). Foretarsus with two pores, near sensillum e and c ( Figs. 15, 16).

Thoracic chaetotaxy given in Table 2. Setae 1 and 2 on pronotum subequal in length ( Fig. 18); mesonotum with 2 pairs of anterior seta (A2, A4), and 9 pairs of posterior setae, lengths of setae P1a, P2a, P5a and P5a' on mesonotum 8.2, 12.7, 1.8 and 2.3 µm, respectively ( Figs. 19, 20). Metanotum with 2 pairs of anterior seta (A2 and A4), and 8 pairs of posterior setae, without P5a' ( Figs. 21, 22). Prosternum with anterior seta A1, A2 ( Fig. 17); mesosternum ( Fig. 20) and metasternum ( Fig. 22) with 4 and 6 anterior setae respectively. All setae on thoracic sternites setiform.

Pronotum without pores, mesonotum ( Fig. 19) and metanotum with pores sl ( Fig. 21). Prosternum, mesosternum and metasternum each with single median pore sc, situated posterior to level of setae M on prosternum ( Fig. 17) and mesosternum ( Fig. 20), but anterior to level of setae M on metasternum ( Fig. 22).

Abdominal chaetotaxy given in Table 2. Urotergite I with two pairs of anterior setae (A1, A2) and five pairs of posterior setae ( Figs. 4, 5). Urotergites II‒VI with 4 pairs of anterior setae (A1, A2, A4, A5) ( Fig. 7), six pairs of posterior seta, P1a and P2a absent, P4a present. Urotergite VII with 8 pairs of posterior seta, P1a, P3a and P4a present ( Fig. 10). Urotergite I with pores al and psm ( Fig. 5); urotergites II‒VII with pores al, psm and psl ( Fig. 7), VIII with pore psm, IX‒XI without pores, XII with a pore ( Fig. 26).

Posterior central seta Pc absent on urosternites IV‒VI (8 posterior setae) ( Fig. 8), present on urosternite VII ( Fig. 9). Bases of setae on segments X‒XII without surrounding ciliation ( Fig. 26). Urosternites I‒VI each with one median pore spm ( Figs. 4, 6, 8), VII with pores spm and spsl ( Fig. 9), VIII and X each with single median pore ( Fig. 27), IX with one median pore and one pair of lateral pores ( Fig. 27), XI without pores, XII with two pairs of pores sam and sal ( Fig. 27).

Abdominal appendages each with two segments and four setae. Striate band on abdominal segment VIII reduced, only a single serrate line present ( Fig. 3). Comb on abdomen VIII rectangular, with 7‒9 teeth ( Fig. 25). Female squama genitalis robust ( Fig. 23). Male squama genitalis with 2+2 setae on dorsal side and 2 setae on ventral side ( Fig. 24).

Distribution. China (Xinjiang).

Etymology. The specific name is derived from Bole City, where the holotype and paratypes were collected.