Pseudachorutes pratensis Rusek, 1973

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 : 18-21

Pseudachorutes pratensis Rusek, 1973

Figs 65–75 , 79

Redescription. Body length without antennae 0.70–1.70 mm. Colour bluish-grey (on slides), ocular plate bluish-black. Tegumental granulation strong.

Antennae shorter than head. Ant. I with 7 setae, Ant. II with 12 setae and Ant. III with 18 (rarely 19) ordinary setae. Ant. III and IV fused dorsally, ventral separation well marked. Sensory organ of Ant. III consisting of: two small, globular internal sensilla, two subcylindrical guard sensilla (ventral sensillum longer 1.3 times than dorsal one) and two guard setae between them; ventral microsensillum present. Ant. IV with about forty ordinary setae and 6 distinct subcylindrical sensilla; dorsoexternal microsensillum present and subapical organite present; apical vesicle slightly divided on three lobes ( Figs 66–67 ).

PAO with 6–9 vesicles, 1.4–1.8 times larger than ocellus B ( Fig. 68 ). 8+8 eyes. Buccal cone short. Mandible with two teeth, styliform maxilla with three lamellae; one of them hooked ( Figs 71–72 ). Labral formula: 4/2,3,4 ( Fig. 79 ). Labium with 2+2 small organites x, without papillate setae L and with 11+11 ordinary setae (A, C, D, F, E, G, f, e, d, b, a present; B absent) ( Fig. 69 ). Perilabial area with 4+4 subequal setae.

Dorsal chaetotaxy as in Fig. 65 with mesosetae and with longer sensory setae s. Formula per half tergum as: 022/11111. Microsensilla on Th. II present. Head with paired setae d1 and without a0. Th. I with 3+3 setae. Th. II and III with 10+10 setae (a2, a5 and m4 setae absent). Abd. I–III with 8+8 setae (m-row setae and a3 setae absent), Abd. IV with 9+9 setae (m-row setae absent), seta s = seta p5. Abd. V with a2 setae, without p2 setae and s = p3.

Ventral chaetotaxy: thoracic sterna without setae, VT with 4+4 setae, Abds. II–VI as in Fig. 75 . Abds. I without setae, Abds. II with 4+4 setae, Abds. III with 5–7+5–7 setae.

Dens with six setae ( Fig. 73 ). Mucro slightly hooked with lamella which obtain apex. Manubrium with 12+12 setae. Tenaculum with 3+3 teeth. Each anal valve with two setae hr ( Fig. 75 ).

Tibiotarsi I, II and III with 19, 19 and 18 setae, respectively, seta B7 absent on tibiotarsus III ( Fig. 70 ). 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, 6 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 small tooth and without lateral teeth ( Fig. 70 ). Empodial appendage absent. Male genital plate as in Fig. 74 .

Material examined. 6 males and 5 females (on slides), Ukraine, Kherson district, Chornomorsky Biosphere Reserve, “Solenoozerna” part, halophyte plants near water, soil, 1.V.2006, leg. Ighor Kaprus’; 2 males and 2 females (on slides), Ukraine, Kherson district, Chornomorsky Biosphere Reserve, “Volyzhyn lis” part, oak forest near water, leaf litter, 26.IV.2006, leg. Ighor Kaprus’; 1 male and 4 females (on slides), Ukraine, Crimea, near Krasnoperekops’k town, steppe vegetation, soil, 15.IX.1998, leg. I. Kaprus’; 1 female (on slide), Ukraine, Dnipropetrovs’k district, near Novomoskovs’k, steppe with domination of Stippa sp., soil, 18.VI.1985, leg. O. Makarova; 2 females (on slides), Ukraine, Donets’k district, Kamiani Mohyly Reserve, steppe vegetation, soil, 25.VI.1998, leg. O. Starostenko; 5 females (on slides), Ukraine, Donets’k district, Proval’sky step Reserve, steppe vegetation, soil, 8.V.2000, leg. O. Starostenko; 2 females (on slides), Ukraine, Lugans’k district, Strilets’ky step Reserve, steppe vegetation, soil, 6.IX.1997, leg. O. Starostenko; 5 males and 8 females (on slides), Ukraine, Donets’k district, near Donetsk town, postindustrial area, black mould soil, 9.VII.1985. Coll. N. Kuznetsova; 1 female (on slide), Ukraine, Ternopil’ district, Medobory Reserve, meadow with steppe vegetation, soil, 24.V.1994, leg. I. Kaprus’.

Biology. The species has been collected in xerophytic habitats. It is probably restricted to steppe communities of South-East Europe. Bisexual.

Remarks. Pseudachorutes pratensis was described by Rusek (1973) on the base of some specimens from the Central Moravia in Czech Republic. Later, Smolis and Twardowski (2006) supplemented description of this species on the base of Polish material. This species is characterized by the paired d1 setae on the head, the absence of setae B on labium and setae a2 on Th. II. Morphological characters of the Ukrainian specimens fit the original description, however there are some differences that extend the range of variability of this species (J. Rusek pers. comm.).

Pseudachorutes pratensis is close to P. libanensis ( Cassagnau & Delamare, 1955) sensu Ellis 1976 from Lebanon and Crete. These two species have similar type of body chaetotaxy (3+3 setae on Th. I, absence setae a2 on Th. II), the small PAO and furca with 6+6 setae on the dens. P. p r a t e n s i s differs from P. libanensis in the absence of setae B and papillate setae L on labium, the shape of mandible (two teeth in P. pratensis , three teeth in P. libanensis ) and also in the structure of the mucro (typical for the genus in P. pratensis , crooked in P. libanensis ).

Figures

FIGURES 65 – 75. Pseudachorutes pratensis Rusek, 1973. 65, dorsal chaetotaxy of body; 66, Ant. III and IV dorsally; 67, Ant. III and IV ventrally; 68, PAO and eyes; 69, labial chaetotaxy; 70, distal part of leg III; 71, mandible; 72, maxilla; 73, furca; 74, male genital plate; 75, 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.