Protaphorura bicampata Gisin 1956

Protaphorura bicampata (Gisin, 1956)

Figs 1–13 & 25

Onychiurus bicampatus Gisin, 1956: 344.

Material examined. 18 females and 6 males on slide, China: Heilongjiang: Honghe Farm (47°35’ N, 133°31’ E), 10 Aug. 2012, soil, Zhang Bing leg. – ibid: 15 females and 4 males on slide, 20 Mar. 2012, Zhang Bing leg.; 5 females and one male on slide, China: Heilongjiang: Xinqing national forest park (48°14’ N, 129°29’ E), 0 2 July, 2011, soil, Sun Xin et al. leg.; 3 females and one male on slide, China: Jilin: Baishan: Fusong: Manjiang (alt. 850m, 41°57’ N, 127°34’ E), 0 1 Sept. 2009, soil, Wu Donghui leg.

Description of Chinese specimens. Body color white in alcohol. Size 1.8–2.4 mm in females, 1.7–2.0 mm in males. Body slender and elongated.

Pseudocellar formula dorsally: 33/022/33332, ventrally: 10/000/00000; subcoxa 1 of legs without pso (Figs 1, 7 & 8). Parapseudocellar (psx) formula ventrally: 00/000/ 111100; subcoxa 1 of legs without psx (Figs 1, 7 & 8). Pseudopores formula dorsally: 00/011/ 111100, ventrally: 00/111/0xxx00 (Figs 1, 7 & 8).

Head. Antennae nearly as long as head. Ant. IV with a subapical organite and basolateral ms about 1/4 of segment length from base. Ant. III sensory organ composed of 5 papillae, 5 guard chaetae, 2 small sensory rods, 2 granulated sensory clubs and a lateral ms (Figs 2 & 3). Ant. I with 10–11 chaetae. Ant. II with 16–17 chaetae. Antennal bases with distinct granulation. PAO composed of 29–40 simple vesicles (Fig. 4). 4+4 p-chaetae between posterior a-pso on head (Fig. 1). Mandible with strong molar plate and 4 apical teeth. Maxilla bearing 3 teeth and 6 lamellae. Maxillary palp simple with 1 basal chaeta and 2 sublobal hairs. Labral chaetae formula 4/342. Labium with 7 proximal, 4 basomedian (E, F, G and f) and 6 basolateral chaetae (a, b, c, d, e, e’); labial type A, papillae A– E respectively with 1, 4, 0, 3, 3 guard chaetae (Fig. 5). Postlabial chaetae 5+5 along ventral groove (Fig. 8).

Body chaetotaxy. Dorsal chaetotaxy usually with some asymmetry, well differentiated into macro-, meso- and microchaetae. Chaetae s very weakly marked. Th. II–III terga with microsensilla laterally (Fig. 1). Th. I tergum with 13–14 chaetae (chaetotaxy type i 3 m) (Figs 1 & 6). Abd. I–III and V terga with chaeta s’ (Figs 1 & 25). Abd. IV tergum with m0 axial chaeta, Abd. V tergum with m0 and p0 axial chaetae, Abd. VI tergum with m0 axial chaeta (rarely with a0) (Fig. 1). Ratio M/sp on Abd. V as 1.4–1.6. Straight lines passing through the bases of chaetae a1 and m1 distinctly convergent on Abd. VI tergum (Fig. 1). Anal spines present on distinct papillae, 0.6 times as long as inner edge of unguis.

Th. I–III sterna with 1+1, 2+2, 2+2 chaetae, respectively. Ventral tube with 8–10 distal chaetae and 2+2 basal chaetae, without anterior chaetae (Fig. 11). Furca reduced to cuticular pocket with 2+2 dental chaetae––1+1 chaetae located on a cuticular fold, remaining 1+1 chaetae located distinctly below the fold; three manubrial rows of chaetae present posteriorly to dental chaetae (Fig. 10). Female genital plate with 25–40 chaetae, male genital plate with 35–50 chaetae (Fig. 12). Male ventral organ absent. Anal valves with numerous acuminate chaetae; each lateral valve with a0, 2a1 and 2a2; upper valve with chaetae a0, 2a1, 2b1, 2b2, c0, 2c1, 2c2 (Fig. 13).

Appendages. Subcoxa 1 of legs I–III with 5, 7 and 6–7 chaetae, subcoxa 2 with 1, 5 and 5 chaetae, respectively. Tibiotarsi of legs I–III with 22 (11, 8, 3), 21 (11, 8, 2) and 22–23 (11, 8, 3 or 4) chaetae, respectively. Unguis with small inner denticle. Unguiculus slender and pointed, as long as inner edge of unguis, without inner basal lamella (Fig. 9).

Ecology. In China, this species was first found in farmland planted with soya bean, but was later also found in marshland and forest.

Remarks. Protaphorura bicampata (Gisin, 1956) is characterized by the pso formula on the body, the absence of the pso on subcoxa 1 of the legs, the presence of chaeta s’ on Abd. I–III and V terga and the straight lines passing through the bases of chaetae a1 and m1 distinctly convergent on Abd. VI tergum. This species was first reported from Denmark by Gisin (1956) and later from Iceland (Bödvarsson 1967), Siberia (Martynova 1976), Britain (Hopkin 1997) and Norway (Fjellberg 1980, 1998). Pomorski (1990) considered P. islandica (Bödvarsson, 1959) to be a synonym of P. bicampata, since the only difference between them was the absence of one pso on the Abd. V tergum. Later (Pomorski 1998), he described Polish specimens as P. bicampata, but with the dorsal pso formula 33/ 022/33333 (as in P. islandica). Fjellberg (1998) mentioned P. bicampata from dry localities and P. islandica from wet localities. Specimens mentioned by Pomorski (1998) are also from wet localities. We therefore reject the synonymy presented by Pomorski (1990).