Hypogastrura yosii Stach, 1964

Jia, Junli, Skarżyński, Dariusz & Konikiewicz, Marta, 2011, A taxonomic study on Hypogastrura Bourlet, 1839 (Collembola, Hypogastruridae) from China, Zootaxa 2981, pp. 56-62 : 61-62

Hypogastrura yosii Stach, 1964

Figs 12–17

Hypogastrura sheyangensis Jiang, Tang & Chen, 2007 syn. nov.

Type material. Lectotype (designed here) male on slide, formerly in alcoholic vial labeled “ Hypogastrura yosii Stach, Hangzhou , China, 2.xii.1962, leg. Kowalski”; paralectotype (designed here): juvenile on slide labeled “ Hypogastrura yosii Stach, Nanjing , 21.xi.1962, leg. Kowalski”; (formerly as syntypes, deposited in the collection of the Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Kraków, Poland). H. sheyangensis paratypes: 2 females and 2 males on slides, China, Jiangsu Province, Yancheng, Sheyang County, National Nature Reserve of Red-Crowned Cranes, 26.iv.2006, collection number C9465, leg. Ji-Qiang Qu et al. (deposited in the collection of the Department of Biology, Nanjing University, China).

Redescription. Body length up to 1.5 mm. Colour violet-black, ventrally paler, eye patches black. Granulation uniform, 5–7 granules between setae p1 on abd. V.

Chaetotaxy of head typical of the genus. Setae short and smooth. Body sensilla (s) 2 times longer than ordinary setae, fine and smooth. Dorsal chaetotaxy of th. II and abd. III–VI as in Figs 12, 13 . Th. I with 3 + 3 setae. Th. II with setae m3–4 present and m2 absent. Th. III with setae m4 present and m2-3 absent. Setae m6 sometimes present on th. II–III. Setae p3 on abd. IV absent, setae p7 present. Abd. V with setae p2 present and m-setae absent. Subcoxae I, II, III with 1, 2, 3 setae respectively. Microsensillum on th. II present.

Ant. IV with simple apical vesicle, subapical organite (or), microsensillum (ms), 9–10 curved short and moderately thick sensilla. Ant. III-organ with two long (outer) and two short (inner) sensilla. Microsensillum on ant. III present. Ant. I with 8 setae (seta p’ present) ( Jiang et al. 2007: Figs 10–11 ).

Ocelli 8 + 8. Postantennal organ 1.5–2.5 as large as nearest ocellus, with 4 lobes each with secondary projecting lobe. Small accessory boss present ( Fig. 14 ). Labrum without apical papillae. Labral setae 5, 5, 4, prelabrals 4. Maxillary head with lamella 1 longer than teeth, with long marginal, apical and subapical filaments and denticles in basal part. Lamella 2 slightly longer than teeth, with marginal filaments ( Fig. 15 ). Labium of the tullbergi type. Outer lobe of maxilla with 2 sublobal hairs.

Tibiotarsi I, II, III with 19, 19, 18 setae respectively. Tenent hair (A1) slightly longer than claw and only weakly clavate. Claws with inner tooth. Empodial appendage acuminate (without basal lamella), reaching middle of claw ( Fig. 16 ).

Ventral tube with 4 + 4 setae. Retinaculum with 4 + 4 teeth.

Furca well developed. Dorsal side of dens with coarse, uniform granulation and 7 setae. Mucro with upturned apex and outer lamella. Ratio dens/mucro 1.8–2.5 ( Fig. 17 ).

Anal spines small, situated on low basal papillae ( Fig. 13 ).

Remarks. The recently described H. sheyangensis ( Jiang et al. 2007) shares morphological characteristics with H. yosii ; therefore, we conclude that the former is a junior synonym of the latter. The following features: labrum without distal papillae and empodial appendages with narrow basal lamella place H. yosii in the H. manubrialis group. The absence of setae p3 makes H. yosii similar to two Nearctic species: H. matura (Folsom, 1916) and H. utahensis (Wray, 1953) (sensu Christiansen & Bellinger 1998). H. matura has 8 cylindrical sensilla on ant. IV and fine granules on the dens ( H. yosii : 9–10 cylindrical sensilla on ant. IV, coarse granules on the dens) and H. utahensis has 3 lobes in the postantennal organ, the m-row of setae on abd. V and only 7 setae on ant. I (in H. yosii 4 lobes in the postantennal organ, abd. V without m-setae, ant. I with 8 setae).

Key to Hypogastrura of China 1, 2

1. Retinaculum quadridentate.............................................................................. 2

- Retinaculum tridentate................................................................................. 5

2. Empodial appendage with narrow basal lamella, head of maxilla with lamellae 4 and 5 shorter than teeth.................................................................................... H. yosii (provinces Zhejiang and Jiangsu)

- Empodial appendage with broad basal lamella, head of maxilla with lamellae 4 and 5 longer than teeth.................. 3

3. Seven setae on dens......................................................... H. heptasetata (Jiangsu province)

- Six setae on dens...................................................................................... 4

4. Ant. IV with simple apical vesicle and pointed sensilla in ventral file..................... H. hexasetata (Hubei province)

- Ant. IV with trilobed apical vesicle and broadened and flattened at tips sensilla in ventral file................................................................................................ H. manghe sp. nov. (Shanxi province)

5. One weakly clavate tenent hair on tibiotarsi............................................. H. verruculata (Shanghai)

- More than one clavate tenent hair on tibiotarsi.............................................................. 6

6. Abd. IV–VI with knobbed macrochaetae, tibiotarsi I with three clavate tenent hairs, dens with 5 setae..... H. distincta (Tibet)

- Abd. IV–VI without knobbed macrochaetae, tibiotarsi I with two clavate tenent hairs, dens with more than five setae...... 7

7. Tibiotarsi I–III with 2, 4, 4 clavate tenent hairs respectively, dens with six setae........ H. quadritenenta (Jiangsu province)

- Tibiotarsi I–III with 2, 3, 3 clavate tenent hairs respectively, dens with seven setae........... H. gracilis (Jiangsu province)

1 Hypogastrura zhangi Zhao, 1998 mentioned in the checklist of Jiang & Yin (2010) has recently been transferred to the genus Ceratophysella Börner, 1932 ( Jia et al. 2010) .

2 Considering insufficient knowledge on the Hypogastrura of China, the keys of Babenko et al. (1994) and Thibaud et al. (2004) should be used in doubtful cases.

Figures

FIGURES 12 – 17. H. yosii (lectotype male): 12, chaetotaxy of th. II; 13, chaetotaxy of abd. III – VI; 14, postantennal organ and ocelli; 15, head of maxilla; 16, claw III with empodial appendage; 17, dens and mucro. Abbreviations in text.

FIGURES 6 – 11. H. manghe sp. nov.: 6, chaetotaxy of ant. III – IV, dorsal side; 7, chaetotaxy of ant. III – IV, ventral side; 8, claw III with empodial appendage; 9, postantennal organ and ocelli; 10, head of maxilla; 11, labium. Abbreviations in text.