Hesperentomon yangi, Bai, Yi & Bu, Yun, 2013

Bai, Yi & Bu, Yun, 2013, Hesperentomon yangi sp. n. from Jiangsu Province, Eastern China, with analyses of DNA barcodes (Protura, Acerentomata, Hesperentomidae), ZooKeys 338, pp. 29-37 : 30-33

Hesperentomon yangi sp. n. Figs 1-25, Table 2

Material examined.

Holotype, female (No. NJ-8), East China, Jiangsu Province, Nanjing City, extracted from the soil samples under some big trees of Qixia Mountain, 32°09.45'N, 118°57.60'E, elev. 200 m, 29-XI-2012. coll. Y. M. Yang. Paratype, 6 females (Nos. NJ-2, NJ-3, NJ-4, NJ-7, NJ-12, NJ-13), 6 males (Nos. NJ-1, NJ-5, NJ-6, NJ-9, NJ-10, NJ-11), same data as holotype. Other materials, 1 maturus junior (No. NJ-14) and 1 larva II (No. NJ-15). Specimens NJ-13, NJ-14 and NJ-15 are voucher specimens with DNA barcodes sequenced. Type specimens are deposited in Shanghai Entomological Museum (SEM), Institute of Plant Physiology & Ecology, Chinese Academy of Sciences.

Description.

Adult body length 1300-1400 µm (n=13), yellow-brown, and foretarsus with deeper color (Fig. 1).

Head. Oblong, length 125-130 µm, width 85-95 µm. Dorsal setae long, other setae short. Setae d6 and sd6 present, sd4 absent. Seta d6 14-15 µm, d7 6-7 µm in length. Paired pores cp, ip and op present, pore fp absent (Fig. 12). Pseudoculus pear-shaped, with short posterior extension, length 12-15 µm, width 8-9 µm. PR=9-11 (Figs 2, 13). Canal of maxillary gland with sausage-like calyx, posterior dilation about equal to length of calyx. CF=7-9 (Fig. 14). Labial palpus well developed, without basal sensillum (Fig. 15). Maxillary palpus with two tapering sensilla, dorsal one (8-9 µm) distinctly longer than lateral one (5-6 µm) (Fig. 16).

Foretarsus. Length 73-83 µm, claw length 18-23 µm, without inner flap, TR=3.5-4.4; empodium length 3-4 µm, EU=0.14-0.18. Dorsal sensilla t-1 and t-2 slender and long (14-15 µm), BS=1.1; t-3 slengder, not reaching base of claw. Exterior sensilla all sward-like and in different length, a surpassing base of c, b and c subequal in length, d close to t2, e broad, f short, g long. Interior sensilla also sward-like in different length, a’ short, b’ -1 longer than b’ -2, c’ -2 longer than c’ -1. Relative length of sensilla: b’ -2 < c’ -1 <f< a’ <t3< b’ -1<(b=c=e) <d<(g= c’ -2) <a <t2 <t1 (Figs 17, 18). Length of middle tarsus 35-37 µm, claw length 18-20 µm. Length of hind tarsus 38-40 µm, claw length 20-23 µm.

Thorax. Thoracic chaetotaxy given in Table 2. Setae 1 and 2 on pronotum subequal in length; mesonotum with eight pairs of posterior setae, P5a and P5 a’ minute; metanotum with seven pairs of posterior setae, P5a minute; setae P1 and P2 on mesonotum 13-15 µm and 17-20 µm respectively. (Figs 3-5). Prosternum without anterior seta A2, mesosternum and metasternum with 6 and 8 anterior setae respectively (Figs 8-10). All setae on thoracic sternites setiform. Pronotum and prosternum without pores. Mesonotum and metanotum with pores sl (Figs 4, 5). Mesosternum and metasternum each with single median pore, situated anterior to level of setae M (Figs 9, 10).

Abdomen. Abdominal chaetotaxy given in Table 2. Tergite I with two pairs of anterior setae (A1, A2) and five pairs of posterior setae. Tergites II–VI with four pairs of anterior setae (A1, A2, A4, A5) and six pairs of posterior setae, P1a, P2a and P3a absent. Tergite VII with 8 posterior setae, P2a absent. Posterior central seta Pc absent on sternites IV–VI (8 posterior setae) (Fig. 7), present on sternite VII (Figs 11, 20). Bases of setae on segments X–XII without surrounding ciliation. Tergites IX–XI, and sternite X with broad, coarsely serrated posterior lamella (Figs 23, 25).

Tergites I–VI with pores psm and al, VII with pores psm, psl and al (Fig. 19), VIII with pores psm and pl, IX, X and XII each with single posteromedial pore (pm), XI without pores (Figs 23, 25). Sternites I–VI each with one medial pore (Fig. 6), VII with one medial pore and one pair of lateral pores (Figs 11, 20), VIII–X each with single medial pore, XI without pores, XII with 3+3 pores.

Abdominal appendages typical of the genus, each with two segments and four setae. Striate band on abdominal segment VIII reduced and only single serrate line present (Fig. 23). Comb on abdomen VIII rectangular, with 7-8 teeth (Fig. 21).

Female squama genitalis robust. Each acrostylus with one slender flap on its outer side (Fig. 22). Male squama genitalis with 2+2 setae on dorsal side and 2+2 setae on ventral side (Fig. 24).

Etymology.

The species is named after Mr. Yi-Ming Yang who collected the specimens and in remembrance of his great contribution to the collection of Protura in China.

Chaetal variability.

Chaetal variations were observed in 5 specimens: on pronotum, with 5 seate, presence of 1 additional seta on left side (No. NJ-2); on prosternum, asymmetrical absence of A1 of right side (No. NJ-3); on sternite I, presence of Pc (Nos. NJ-4, NJ-6, NJ-12); on sternite IV and V, presence of Pc (No. NJ-12).

Distribution.

Jiangsu (Nanjing), China.

Diagnosis.

Hesperentomon yangi sp. n. is characterized by 12 posterior setae on tergites II–VI, 8 posterior setae on sternites IV–VI (seta Pc absent), absence of seta sd4 on head, absence of seta P2a on tergite VII, 6 and 8 anterior setae on mesosternum and metasternum respectively, and few teeth on comb.

Remarks.

Hesperentomon yangi sp. n. is similar to Hesperentomon xiningense Bu & Yin, 2007 and Hesperentomon nanshanensis Bu & Yin, 2007 in having 8 posterior setae on sternites IV–VI (seta Pc absent), 12 posterior setae on tergite IV–VI, and the absence of seta P2a on tergite VII. It can be distinguished from those two species by the chaetotaxy of mesosternum and metasternum (6 and 8 anterior setae in Hesperentomon yangi sp. n. respectively vs. 4 and 6 anterior setae in Hesperentomon xiningense and Hesperentomon nanshanensis ), chaetotaxy of head (setae sd4 absent in Hesperentomon yangi sp. n. vs. present in the later two species), porotaxy of head (frontal pores fp absent and interpseudocular pores ip present in Hesperentomon yangi sp. n. vs. fp present and ip absent in the later two), porotaxy of sternite VII (3 pores in Hesperentomon yangi sp. n. vs. 1 pore in the later two). It also differs from Hesperentomon xiningense in the length of foretarsal sensillum b subequal length to c (b distinctly longer than c in Hesperentomon xiningense ), short sensillum b’ -2 which not reaching base of seta α 7 ( b’ -2 surpassing base of seta α 7 in Hesperentomon xiningense ), and the presence of regular teeth on hind margin of striate band (with sparse unregular teeth in Hesperentomon xiningense ). It also differs from Hesperentomon nanshanensis in the chaetotaxy of abdominal segment X (10 and 6 setae on tergite and sternite repectively in Hesperentomon yangi sp. n. vs. 8 and 4 setae in Hesperentomon nanshanensis ) and shape of maxillary gland (posterior dilation about equal length of the calyx in Hesperentomon yangi sp. n. vs. about 1/2 length of the calyx in Hesperentomon nanshanensis ).