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.

Figures

FIGURES 1–10. Hesperentomon bolense sp. n. (Holotype, BL1705D): 1. Habitus; 2. Head, dorsal view; 3. Striate band; 4. Urosternite I; 5. Urotergite I; 6. Urosternite II; 7. Urotergite II; 8. Urosternite IV; 9. Urosternite VII; 10. Urotergite VII (BL1702D). Scale bar: 1, 100 µm, 2–10, 20 µm.

FIGURES 11–20. Hesperentomon bolense sp. n. (Holotype, BL1705D): 11. Head; 12. Canal of maxillary gland; 13. Maxillary palpus; 14. Labial palpus; 15. Foretarsus, exterior view; 16. Foretarsus, interior view; 17. Prosternum; 18. Pronotum; 19. Mesonotum (BL1702D); 20. Mesosternum (BL1702D). Arrows show pores. Scale bar: 20 µm.

FIGURES 21–27. Hesperentomon bolense sp. n. (Holotype, BL1705D): 21. Metanotum; 22. Metasternum; 23. Female squama genitalis (BL1702D); 24. Male squama genitalis; 25. Comb. 26. Tergites VIII–XII; 27. Sternites VIII–XII. Arrows show pores. Scale bar: 20 µm.