Pseudachorutes janstachi, Kaprus’, Ighor J. & Weiner, Wanda M., 2009

Kaprus’, Ighor J. & Weiner, Wanda M., 2009, The genus Pseudachorutes Tullberg, 1871 (Collembola, Neanuridae) in the Ukraine with descriptions of new species, Zootaxa 2166, pp. 1-23 : 9-11

Pseudachorutes janstachi sp. nov.

Figs 32–41 , 81

Description. Body length without antennae 0.65-0.70 mm. Colour in alcohol bluish-grey, ocular plate bluishblack. Tegumental granulation fine.

Antennae shorter than head. Ant. I with 7 setae, Ant. II with 12 setae and Ant. III with 19 ordinary setae. Ant. III and IV fused dorsally, ventral separation well marked. Sensory organ of Ant. III consisting of two small, slightly bent internal sensilla, two subcylindrical guard sensilla (ventral sensillum is 1.2 times as long as dorsal one) and two guard setae between them; ventral microsensillum present. Ant. IV with about fifty ordinary setae and six distinct subcylindrical sensilla; dorsoexternal microsensillum and subapical organite present; apical vesicle simple or slightly bilobated ( Figs 33–34 ).

PAO round, with 7 vesicles, 1.8 times larger than ocellus B ( Fig. 38 ). 8+8 eyes. Buccal cone short. Mandible with three teeth, tooth in the angle of mandible small ( Fig. 36 ). Styliform maxilla with two lamellae, one of them hooked ( Fig. 37 ). Labral formula: 2/2,3,4 ( Fig. 81 ). Labium with 2+2 organites x and papillate setae L, with 12+12 ordinary setae ( Fig. 35 ). Perilabial area with 5+5 subequal setae.

Dorsal chaetotaxy as in Fig. 32 , with mesosetae and longer sensory setae s. Formula per half tergum as: 022/11111. Some setae on abdominal tergites IV–VI slightly thickened. Microsensilla on Th. II present. Head with unpaired seta d1, without a0 setae. Th. I with 3+3 setae. Th. II with 12+12 setae (a2 and a5 setae present, m4 absent) and Th. III with 11+11 setae (a2 and m4 setae absent, a5 setae present). Abd. I–III with 8+8 setae (m-row and a3 setae absent) and Abd. IV with 9+9 setae (m-row setae absent), seta s = p5. Abd. V with a2 and without p2 setae, seta s = p3.

Ventral chaetotaxy: thoracic sterna without setae, VT with 4+4 setae, Abds. II–VI as in Fig. 41 . Abds. I without setae, Abds. II with 4+4 setae, Abds. III with 7+7 setae.

Dens with six setae ( Fig. 40 ). Mucro hooked with broad lateral lamella. Manubrium with 13+13 setae. Tenaculum with 3+3 teeth. Each anal valve with two setae hr ( Fig. 41 ).

Tibiotarsi with one blunt tenent hair (A1 seta). Tibiotarsi I, II and III with 19, 19 and 18 setae, respectively, B7 seta absent on tibiotarsus III ( Fig. 39 ). Femora I, II and III with 13, 12 and 11 setae, trochanters I, II and III with 6, 6 and 6 setae, coxae I, II and III with 3–4, 7 and 7 setae, subcoxae 2 of legs I, II and III with 0, 2 and 2 setae, subcoxae 1 of legs I, II and III with 1, 2 and 2 setae, respectively. Claw with inner tooth and without lateral teeth ( Fig. 39 ). Empodial appendage absent.

Type material. Holotype: female (on slide), Ukraine, Donets’k district, Velyko-Anadyrsky lis, oak forest, leaf litter, 7.V.2001, leg. N. Sandul. Paratype: female (on slide), the same data as holotype. The material is preserved in SNHMU.

Etymology. The new species is dedicated respectfully to Professor Jan Stach, in his 130 anniversary of birthday.

Biology. Pseudachorutes janstachi sp. nov. has been collected only in leaf litter of oak forest. Only females are known.

Discussion. Pseudachorutes janstachi sp. nov. is related to P. parvulus Börner, 1901 and P. corticicolus Schäffer, 1896 (see Table 1). All species have the same type of mucro (hooked with long and broad lamella) and claw (with inner teeth and without lateral ones), the same number of setae on Th. I and on dens, seta a2 present on Th. II and small number of vesicles in the PAO. They differ distinctly in the labral formula and the shape of tenent hair. Besides, P. janstachi and P. parvulus possess the 2+2 small organites x and papilate seta s on the labium, while P. coriticicolus lacks these structures.

These three species differ also in the shape of mandible. In P. janstachi mandible has three teeth, the tooth in the angle of mandible small. The mandible in P. parvulus has four teeth: the subapical tooth is quite large and the tooth in the angle of mandible is minute, whereas P. corticicolus has also four teeth, but both inner teeth are large. The new species and P. corticicolus have setae m5 on the terga of Th. II and III, while in P. parvulus this seta is absent. Setae m4 are absent on the Abd. I–III in the new species and in P. parvulus ; P. corticicolus has these setae.

Figures

FIGURES 32 – 41. Pseudachorutes janstachi sp. nov. 32, dorsal chaetotaxy of body; 33, Ant. III and IV dorsally; 34, Ant. III and IV ventrally; 35, labial chaetotaxy; 36, mandible; 37, maxilla; 38, PAO and eyes; 39, distal part of leg III; 40, furca; 41, chaetotaxy of Abds. I – VI.

FIGURES 76 – 84. Shape and chaetotaxy of labrum: 76, Pseudachorutes corticicolus (Schäffer, 1896); 77, Pseudachorutes parvulus Börner, 1901; 78, Pseudachorutes subcrassus Tullberg, 1871; 79, Pseudachorutes pratensis Rusek, 1973; 80, Pseudachorutes scythicus sp. nov.; 81, Pseudachorutes janstachi sp. nov.; 82, Pseudachorutes palmiensis Börner, 1903; 83, Pseudachorutes vasylii sp. nov.; 84, Pseudachorutes vitalii sp. nov.