Paranura cassagnaui Smolis & Deharveng, 2015, sp. nov.

Paranura cassagnaui sp. nov.

Figs 39–47, Tables 7–8

Etymology. The new species is dedicated to the excellent French collembologist Paul Cassagnau who established the genus Paranura and the tribe Paranurini.

a) Cephalic chaetotaxy––dorsal side.

b) Chaetotaxy of antennae.

Terga Legs

Di De Dl L Scx2 Cx Tr Fe TT th. I 1 2 1 – 0 3 6 13 19 th. II 3 3+s 3+s+ms 3 2 7 6 12 19 th. III 3 4+s 3+ s 3 2 8 6 11 18

Sterna

abd. I 2 3+ s 2 3 VT: 4

abd. II 2 3+ s 2 3 Ve: 5; Vel present

abd. III 2 3+ s 2 4 Ve: 5; Fu: 4–5 me, 8 mi

abd. IV 2 2+ s 3 7 –8 Vel: 4; Vec: 2; Vei: 2; Vl: 4

abd. V (3+3) 7+s Ag: 3; chaetae L‘ and Vl present abd. VI 7 Ve: 12–13; An: 2 mi

Diagnosis. Body white. 2+2 eyes on head. Tubercles developed on dorsal side of abdomen, reticulations absent. Head with chaetae O, A and E. Head with three ocular chaetae. Thorax I with 2 chaetae De. Thorax II–III with 3 chaetae Di. Thorax II–III with 3 and 4 ordinary chaetae De respectively. Abdomen V with 3+3 chaetae Di. Abdomen V slightly longer than VI. Abdomen without clavate chaetae. Furca rudimentary with microchaetae. Male ventral organ absent. Tibiotarsi with chaetae M.

Description. Habitus typical for Paranura Axelson, 1902 genus. Buccal cone elongated. Body length (without antennae) 0.55 (juvenile)–1.4 mm (holotype: 1.15 mm). Colour of body when alive and in alcohol white. Development of tubercles as in Fig. 39. Ordinary dorsal chaetae (Figs 39, 44) differentiated into short, thin, acuminate microchaetae, medium size, smooth, acuminate mesochaetae and long, nearly smooth (with small denticles visible under large magnification, Fig. 44), relatively thick, rounded or arc-like at apex macrochaetae Ml and Mc. No plurichaetosis on body.

Head. Antennae slightly shorter than head (Fig. 39). S-chaetae of ant. IV relatively long and thin, S1 and S2 thinner than others, and S1distinctly longer (Fig. 42). Apical bulb trilobed (41). Chaetotaxy of antennae as in Fig. 42 and Tab. 7. Buccal cone relatively long and rounded at apex (Fig. 40). Maxilla needle-like, mandible simple with three teeth. Chaetotaxy of labium as in Fig. 43, labial papillae x absent. Labrum chaetotaxy 4/2,4 (Fig. 40). Group Vi with 6+6 chaetae (Fig. 43). Groups Vea, Vem and Vep with 4, 3 and 4 chaetae respectively. Dorsal chaetotaxy of head as in Tab. 7. and Fig. 39. Dorsal chaetotaxy of central area on head complete, with 3 chaetae Oc and chaetae A, B, C, D, E, F, G, O. Line of chaetae Di2–De2 crosses line Di1–De1 on head (cross-type, Deharveng 1983). 2+2 relatively large black eyes with diameter about three times as large as the diameter of chaeta Ocm socket (Fig. 39).

Thorax, abdomen, legs. Dorsal chaetotaxy as in Fig. 39 and in Tab. 8. Ventral chaetotaxy as in Tab. 8 and Figs 46, 47. S-chaetae long, equal to nearby macrochaetae (Figs 39, 45). S-chaetae formula of body: 022/11111, smicrochaeta on Dl of th. II present. Furcal remnant with 4–5 mesochaetae and 8 microchaetae (Fig. 47). Male without ventral modified chaetae (“male ventral organ”). Claw without internal tooth. Chaeta M present on tibiotarsus, chaetae B4 and B5 short. Chaetotaxy of legs as in Tab. 8.

Types. Holotype: female on slide, United States of America: Oregon, Blue River Ranger District of Willamette National Forest, neighborhood of H. J. Andrews Experimental Forest, “Wolf Rock” site, old-growth forest of Tsuga heterophylla Zone (tree species: Douglas fir Pseudotsuga menziessi, western red-cedar Thuja plicata), litter, 27.IX. 2006, leg. A. Smolis. Holotype deposited in DIBEC. Paratypes: female, male and 4 juveniles on slides, same data as holotype. Two paratypes (female and juv.) are housed in MNHN, the others in DIBEC.

Other material. 3 females and 4 juveniles on slides (DIBEC), USA: Oregon, Blue River Ranger District of Willamette National Forest, neighborhood of H. J. Andrews Experimental Forest, 6.5 km East of Blue River town, c. 520–550 m above sea level, “Cougar 1” site, old-growth forest of Tsuga heterophylla Zone, litter, 27.IX– 3.X.2006, leg. A. Smolis.

Remarks. The following morphological characters: white body, 2+2 eyes, complete chaetotaxy of central area of head, tubercle De of th. III with 5 chaetae and tubercle Di of abdomen V with 3+3 chaetae place the new species near P. modesta Deharveng, 1989, described from Northern Thailand (Deharveng 1989). Paranura cassagnaui sp. nov. differs from it in the presence of microchaetae on furcal remnant (in modesta absent), the absence of male ventral organ (in modesta present), the presence of chaeta Ve1 on abd. II (in modesta absent) and the fusion of tubercles Di on abd. V (in modesta separate). In general appearance (especially chaetotaxy of body) the new species seems to be very similar to Alaskan specimens of Paranura recorded by Fjellberg (1985) as P. quadrilobata Hammer, 1953.

Biology. The new species is resident in montane (from 700–1400 m) conifer old-growth forest (Fig. 27) of the Tsuga heterophylla Zone (Franklin & Dyreness 1988). It inhabits only thick litter and it was not found in soil/dead wood samples. Bisexual species.