Orogastrura tetrophthalma, Deharveng & Bedos & Duran, 2015

Deharveng, Louis, Bedos, Anne & Duran, Vanesa, 2015, Two new species of Poduromorpha (Collembola) from the Mercantour National Park (Alpes-Maritimes, France), with comments on pseudopore patterns, Zoosystema 37 (1), pp. 179-191 : 181-184

Orogastrura tetrophthalma n. sp.

( Figs 1-4 )

TYPE MATERIAL. — France. Alpes-Maritimes, Saorge, Tête de la Poudrière, 30.VI.2010, soil near the crest, in open forest of Larix decidua Mill., Berlese extraction, L. Deharveng, A. Bedos & Sun Xin leg. (sample M100630-DB08; 7.42459E, 44.01388N; altitude 1992 m.), ♀ holotype on slide (collection number MNHN-EA021550). — Same data as holotype (sample M100630-DB03), ♂ paratype on slide (collection number MNHN-EA021551). — France. Alpes-Maritimes , Saint-Dalmas-le-Selvage, Sestrière forest, 08.VI.2009, moss on rocks, in open forest of Larix decidua Mill., Berlese extraction, L. Deharveng & A. Bedos leg. (non-standard sample M090608- DB18; 6.8235944E; 44.2926706N; altitude 1995 m.), 3 paratypes on slides (1 ♂, collection number MNHN-EA021552; 2 ♂, collection numbers MNHN-EA021553 and 021554) ; 8 barcoded paratypes (collection numbers MNHN-EA021174 to 021181, but vouchers not retrieved after extraction; 5 of them with CO1 sequences). All types deposited in MNHN .

NAME DERIVATION. — From the Greek roots tetra (four) and ophthalm - (eyes), in reference to the four eyes per side of the new species.

DISTRIBUTION AND ECOLOGY. — In its two occurrences, Orogastrura tetrophthalma n. sp. was found in moss on rocks and on soil among heath vegetation in open forest of Larix decidua Mill. at high elevation in the southwestern Alps.

DESCRIPTION

General

Length: 650-800 µm. Body stocky-elongate, rather flat ( Fig. 1 ). Antennae subcylindrical, equal to head diagonal. Colour: beige-violet to reddish-beige, pale. Eyes black, 4 + 4. Second-

New Poduromorpha (Collembola) from Mercantour ( France)

ary granulation regular, granules the size of ordinary chaeta sockets or smaller. Six secondary granules between chaetae p1 of Abd. V.

Chaetal morphology

Ordinary chaetae of medium size, smooth, acuminate, subequal on tergites, except on head and Abd. V-VI, where the ratio long - est/shortest chaetae reaches 2.5-3.0. S-chaetae of four types: 1) long on tergites, slightly thickened, subparallel, slightly longer than, or subequal to, longest ordinary chaetae, similar to blunt chaetae of Ant. IV ; 2) medium size, thickened on Ant. III-IV; 3) a pair of short ms, bent and swollen in AIIIO; and 4) short ms, quenelle-like, thick, but thinner than type iii, present at three locations: a lateral one lying in an elongate depression on Th. II, a lateral one in AIIIO and a distal one on Ant. IV.

Ocular area ( Fig. 2C ).

With 4 + 4 black ocelli. PAO with 4 lobes, 3.5 × as long as ocellus diameter; each lobe oval-fusiform, anterior lobes larger than posterior ones.

Mouthparts ( Fig. 2B, D )

Clypeo-labral formula a0 + 2 + 4/5,5,4, with four anterior chaetae longer. Four more or less distinct subapical papillae dorsally on labrum and a very fine row of microvillosities on its apical edge. Labium not examined in detail, with rather short chaetae. Maxillary outer lobe with one sublobal hair. Mandible with five (right) or four (left) teeth. Maxilla stocky, with short lamellae, not examined in detail.

Antennae ( Fig. 2 E-H)

Ant. I and II with 7 and 13 ordinary chaetae, respectively; Ant. III with 19 ordinary chaetae; AIIIO constituted by two small ms flanked by two thickened guard S-chaetae and a small external ms ( Fig. 2H ). Ant. IV dorsally with 14 blunt chaetae (chaetae “mou”), two ordinary chaeta (i and a distal one), 5 S-chaetae thickened and curved (S1, 2, 4, 7 and 8), of same size as the guard S-chaetae of Ant. III, and one ms lying in elongate socket ( Fig. 2G ); subapical organite very small; apical exsertile vesicle simple, very large ( Fig. 2F ); ventrally, various chaetae present but no sensorial rasp.

Dorsal chaetotaxy ( Fig. 2A )

Chaeta a0 present on head. Abdominal tergites I, II and III with 3 + 3, 14 + 14 and 14 + 14 chaetae. Chaetae m1 present on Th. II-III and Abd. IV. Chaeta m2 absent on Th. sII-III and Abd. IV. Lateral ms of Th. II relatively large, lying in a depression. S-chaetae position from axis on tergites: 4,4/5,5,5,5,3. Thoracic sternites without chaetae. Male genital plate not observable; female genital plate with nine circumgenital chaetae and 1 + 1 genital chaetae.

Legs ( Fig. 3 )

Tibiotarsi I,II, III with 19,19, 18chaetae,each with one,pointed, tenent hair, slightly longer than other chaetae. Femora I, II, III with 13, 12, 11 chaetae. Trochantera with 6, 7, 7 chaetae, of which one is thinner. Coxae I, II, III with 3, 7, 8 chaetae. Subcoxae 2 of legs I, II, III with 0,2,2 chaetae.Subcoxae 1 of legs I, II, III with 1, 2, 3 chaetae. Secondary granules not developed on large parts of trochanter and femur, being absent dorsally, posteriorly and ventro-distally on femur. Claw untoothed; unguiculus short, 3.5 × shorter than inner edge of claw.

Sixth abdominal segment ( Fig. 4A, B )

Abd. VI with two very short anal spines, without distinct papillae. Three short mesochaetae hr on each anal valve, those of the upper valve longer. Two strong Mac above upper chaetae hr, bent toward axis and converging proximally. An uneven chaeta just above these Mac, another one just below.

Abdominal appendages

Ventral tube with 4 + 4 chaetae.

Furca as in Fig. 4C . Tenaculum with 3 + 3 teeth. Manubrium with 12-14 + 12-14 posterior chaetae. Dens reduced, with three dorsal chaetae; mucro small, 4-5 × shorter than dens, triangular, separated from dens.

Ratios: GIII:eIII:GI:eI:d:m:eA = 22:6:21:5:29:6:6

REMARKS

The genus Orogastrura now includes eight species ( Deharveng & Gers 1979; Arbea & Jordana 1990; Babenko et al. 1994): five species from the Pyrenees, one from Siberia, one ( O. parva (Gisin 1949)) widespread in central Europe, mostly in eastern Alps and Carpathians, but also present in the Abruzzo ( Italy), and O. tetrophthalma n. sp., which is the only species restricted to the Alps. The latter is also the only species with four ocelli per side, i.e. the most reduced number in the genus. The ocelli are arranged in an unusual pattern, with none being posterior to chaeta Oca. Apart from the ocular plate characters, this species is very similar to O. dilatata and O. fusca Gers, 1980 from the Pyrenees in most morphological characters (see key), as well as in its ecology, since all three species live at high altitudes in the upper subalpine or Alpine zone.

Figures

FIG. 1. — Orogastrura tetrophthalma n. sp.: habitus, specimens from sample M090608-DB18. Body size: 650-800 µm.

FIG. 2. — Orogastrura tetrophthalma n. sp.: A, dorsal chaetotaxy; B, maxillary outer lobe; C, ocular area; D, labrum; E, right antenna in dorsal view with numbers of Ant. IV S-chaetae; F, apical vesicle of Ant. IV; G, s-microchaeta of Ant. IV; H, s-microchaeta of Ant. III organ. Abbreviations: see material and methods.Scale bars: A, 150 µm; C, E, 20 µm; B, D, 10 µm.

FIG. 3. — Orogastrura tetrophthalma n. sp. leg II. Pale grey, area without secondary granules (primary granules only). Scale bar: 20 µm.

FIG. 4.— Orogastrura tetrophthalma n. sp.: A, dorsal side of Abd.V-VI;B, ventral side of Abd.VI;C, posterior side of furca.Scale bars:A, 30 µm;B, 20 µm; C, 25 µm.