Xenylla andrzeji, Buşmachiu & Weiner, 2008

Buşmachiu, Galina & Weiner, Wanda Maria, 2008, Species of the genus Xenylla Tullberg, 1869 (Collembola: Hypogastruridae) from the Republic of Moldova, Zootaxa 1959 (1), pp. 65-68 : 65-67

Xenylla andrzeji sp. nov.

Figs 1–8

Diagnosis. Habitus and buccal cone typical for the genus Xenylla . Seta c1 and c2 on the head present. Labrum with 4/254 setae. Labium with seta F 3.3 times longer than seta E. Furca short, mucrodens with 1 posterior seta.

Description. Holotype length (male): 0.91 mm, length of female paratypes 0.94–1.1 mm, males: 0.88–0.95 mm. Colour: dorsal side grey-blue, ventral side spotted blue, ocular plate dark. Tegumental granulation rather fine.

Antennae as long as head. Antennal segment I with 7 setae, antennal segment II with 12 setae. Sensory organ of antennal segment III consisting of: two small subcylindrical internal sensilla conspicuous, two small subcylindrical guard sensilla and ventral microsensillum. Antennal segment IV with 4 short subcylindrical sensilla in the same size, small microsensillum between two latero-external sensilla, small subapical organite; simple apical vesicle ( Fig. 2 ).

5+5 eyes present, postantennal organ absent. Buccal cone typical for the genus. Chaetotaxy of labrum: 4/2,5,4 ( Fig. 3 ). Maxillary outer lobe with three sublobal setae ( Fig. 5 ). Labium with seta F 3.3 times longer than seta E ( Fig 4 ).

Dorsal chaetotaxy as in Fig. 1 with rather short, serrated setae and a pair of long setae on abdominal tergum VI. Thin long sensory setae s present, with formula per half tergum: 022/11111. Head with seta a0, setae d1, c1 (absent in one specimen) and c2 present. Seta l3 as long as seta l1. Ventral side of head with setae p1 and m3. Thoracic terga II and III with seta a2 displaced posteriorly compared with seta a1; seta p2 displaced anteriorly compared with seta p1, with setae la1–la3, m3 and p3 present. Thoracic sterna II and III with 1+1 setae (rarely 2+2 on thoracic sternum III). Abdominal tergum IV with setae a3 and a4, setae p4 displaced anteriorly, p5=s. Setae a2 on abdominal tergum V absent. Abdominal tergum VI with small anal spines (ratio claw III: anal spines = 0.8). Ventral abdominal chaetotaxy as in Fig. 8 . Ventral tube with 4+4 setae. Abdominal sternum II with setae a6 (setae a5 absent) and setae p1–6 (setae p3 longest), abdominal sternum III with setae a1–6 and setae p3–6 present (setae p4 longest). Abdominal sternum IV with setae a1–2 (3), setae m1(0)–3, setae p1–4(3) (setae p1 displaced anteriorly). Two anterior anal valves with 2 setae hr each.

Tibiotarsi I, II and III with 19, 19 and 18 setae respectively, with setae A1 and A7 (after Deharveng 1983) capitate (ratio claw III: capitate setae = 1:2–2.3), setae M present. Seta B7 absent on the tibiotarsus III ( Fig. 6 ). Femora I, II and III with 12, 11 and 10 setae respectively, trochantera with 5, 5 and 5 setae respectively, coxae I, II and III with 3, 8 and 8 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 3 setae respectively.

Furca short, mucrodens with 1 posterior seta ( Fig. 7 ). Ratio claw III: mucrodens = 1:0.6. Retinaculum with 2+2 teeth.

Type material. Holotype: male ( MDA –08–6/3), paratypes three males and two female ( MDA –08–6/1,2,4,5,6), paratypes two females and a male ( MDA –08–7/1,2,3) in ISEA . Paratypes 8 females and 10 males ( MDA –08–1, MDA –08-2, MDA –08–3, MDA –08–4, MDA –08–5) in IZM .

Type locality. Republic of Moldova, Plaiul Fagului State Nature Reserve , village Radenii Vechi, (N 47°17´, E 28°01´), 23.iv.2008, in moss on rotten oak log, coll. G. Buşmachiu.

Other material. The species is recorded from two other localities in the Republic of Moldova, from litter and moss of natural deciduous forests: Butuceni (N 47°18´, E 28°57´), 22.iv.2008, 1 ex., coll. G. Buşmachiu ; Ivancea (N 47°17´, E 28°45´), 25.iii.2007, 3 ex., coll. G. Buşmachiu.

Etymology. We have the honour of dedicating the new species to Professor Andrzej Szeptycki, the eminent taxonomist in Collembola and Protura, and our friend, who passed away on September 29, 2008.

Discussion. The new species belongs to group III of the genus Xenylla ( Babenko et al. 1994) that is distinguished by the presence of setae c1 and c2 on the dorsal surface of head, and by seta a2 displaced posteriorly, seta p2 displaced anteriorly on thoracic terga II and III (characters h 1 and h 2). Xenylla andrzeji sp. nov. is close to Xenylla myrmecophila described by Stebaeva and Potapov (in: Babenko et al. 1994) from East Siberia ( Russia). Both species share the following characters (besides those mentioned previously): body with serrated setae, seta l1 as long as l3, seta a2 on abdominal tergum V and seta a5 on abdominal sternum II absent, short mucrodens with one seta each. They differ in size of the body (0.7 mm for X. myrmecophila and 0.9–1.1 mm for the new species), in the chaetotaxy of abdominal tergum IV in that setae a3 and a4 on abdominal tergum IV is present in X. andrzeji and absent in X. myrmecophila . The new species can be easily recognized by the length of the labial seta F, being 3.3 times longer than seta E, while in X. myrmecophila they are equal in length. Xenylla andrzeji is frequent in moss and litter, while X. myrmecophila was found in nests of Formica pratensis Retzius.

Figures

FIGURES 1–8. Xenylla andrzeji sp. nov.: 1, dorsal chaetotaxy; 2, antennal segments III and IV, dorsally; 3, labrum; 4, mental, submental and perilabial chaetotaxy; 5, maxillary outer lobe; 6, distal part of leg III; 7, furca; 8, ventral chaetotaxy of abdominal sterna I–VI.