Stachorutes najtae, Fanciulli & Dallai & Frati & Carapelli, 2017

Fanciulli, Pietro Paolo, Dallai, Romano, Frati, Francesco & Carapelli, Antonio, 2017, Stachorutes najtae n. sp., a new psammophile species of Collembola from Italy (Neanuridae, Pseudachorutinae), Zoosystema 39 (1), pp. 31-36 : 32-36

Stachorutes najtae n. sp.

( Figs 1-3 ; Table 1)

TYPE MATERIAL. — Holotype. Italy, Park of Burano Lake (42°24’4.141’’N, 11°21’35.662’’E) (5. IV.2011) preserved in DSV . Paratypes. 15 paratypes mounted on slides same localities of holotype (12 ♀, 3 ♂); other paratypes from the Natural Park of Maremma (42°38’36.1’’N, 11°03’27’’E) (16.III.2013) (9 specimens mounted on slides, 6 ♀ and 3♂) and 3 specimens (♀) on slides from the Park of S. Rossore (43°47’13.1’’N, 10°16’11.1’’E) (22.V.2013). 17 paratypes deposited in the DSV (8 ♀ and 2 ♂ from the Park of Burano Lake; 4 ♀ and 1♂ from the Natural Park of Maremma; 2 ♀ from the Park of S. Rossore) ; 10 paratypes deposited in the MNHN (4 ♀ and 1 ♂ from the Park of Burano Lake ; 2 ♀ and 2 ♂ from the Natural Park of Maremma ; 1♀ from the Park of S. Rossore) .

HABITAT. — Specimens were collected by means of a corer in the coastal sandy dunes of three Tuscany Parks: Burano Lake, Maremma and S. Rossore; collecting areas are covered by herbaceous and shrubby vegetation mainly represented by psammophile and halophile plants, such as: Ammophila arenaria (L.), Echinophora spinosa (L.), Euphorbia peplis L., and Othantus maritimus (L.).

TYPE LOCALITY. — Italy, Park of Burano lake (42°24’4.141’’N, 11°21’35.662’’E).

DIAGNOSIS. — Habitus typical of the genus with 4 +4 eyes, dens with six chaetae and mucro well separated from dens.

ETYMOLOGY. — The new species is named in the memory of our dear friend Judith Najt for her valuable contribution to the knowledge of springtails.

DESCRIPTION

Habitus ( Figs 1A ; 3A )

Length of body 0.6-0.7 mm. White body colour with minute granules of blue pigment uniformly distributed. Tegument granulation fine and uniform.

Antennae

Antennae slightly shorter than the cephalic diagonal. Ant. l with 7 chaetae, Ant. II with 11 chaetae ( Fig. 2C ). Ant. III and IV dorsally fused; chaetotaxy as in Figures 2A, B ; 3C . Sensory organ of antennal segment III consisting of two small sensilla inside a cuticular pocket protected by two cylindrical guard sensillae ( Fig. 2A, B ). Apex of Ant. IV with a simple vesicle ( Figs 2A, B ; 3C ), subapical organite, microsensillum, i chaeta and 5 cylindrical sensilla ( Fig. 2A, B ). Ocular plate with 4 + 4 ocelli strongly pigmented; post antennal organ constituted by 7-9 simple vesicles ( Figs 1D ; 3B ). Buccal cone short, maxilla styliform, mandible not well visible in the slides, probably with two distal teeth. Labium with 9 chaetae (A, B, C, D, E, F, G, e, f) ( Fig. 1C ); labrum with 2/2,4 chaetae. Dorsal chaetotaxy ( Fig. 1A ; Table 1) Chaeta a0 absent on the head, unpaired chaeta d1 present. Th. III without m3. Ventral chaetotaxy of the head as in Fig. 1C . Sensillar formula 022/11111; sensilla are thicker and longer than ordinary chaetae. Thoracic sterna without chaetae; ventral tube with 4 chaetae. Ventral chaetotaxy of abdomen as in Fig. 1B . Furca relatively short, dens with 6 chaetae, mucro clearly distinct from the dens about ⅓ of its length ( Figs 2G ; 3D ). Retinaculum with 3+ 3 teeth without accessory chaetae ( Fig. 2G ). Male and female genital openings as in Figure 2H, I . Tibiotarsi I, II, III with 18, 18 and 17 chaetae respectively; femora I, II, III with 13, 11, 11 chaetae respectively ( Fig. 2 D-F). Trochanters I, II, III with 6, 6, 5 chaetae, coxae I, II, III with 3, 7, 7/8 chaetae respectively and subcoxae with 2 chaetae each. Claw without internal teeth, empodial appendage absent.

REMARKS

Stachorutes najtae n. sp. is characterized by the presence of 4+ 4 eyes in the ocular plate, six chaetae on dens; chaetae a0 on head absent, d1 present. The new species is similar to Stachorutes gracilis Smolis & Shvejonkova, 2006 with which it shares the same number of eyes, 4+ 4. However they differ for the number of chaetae on dens, four in S. gracilis and six in S. najtae n. sp. and for the different chaetotaxy of the legs; in particular there are 13, 13, 12 chaetae on tibiotarsi I, II, III of S. gracilis while there are 18, 18, 17 on those of S. najtae n. sp.; femora I, II, III with 10, 10, 9 in S. gracilis vs 13, 11, 11 in S. najtae n. sp.; trochanters with five chaetae each in S. gracilis vs 6, 6, 5 chaetae on trochanters I, II, III of the new species. Six species of Stachorutes ( S. longirostris Deharveng & Lienhard, 1983 ; S. navajellus Fjellberg, 1984 ; S. ruseki Kovác, 1999 ; S. scherae Deharveng & Lienhard, 1983 ; S. tatricus Smolis & Skarzynski, 2001 ; S. cuihuaensis Gao & Yin, 2007 ) as well as S. najtae n. sp. share six chaetae on dens, however the new species can be easily recognized from all of them for several different features including the number of eyes that appears the most simple and effective diagnostic character.

Figures

FIG. 1. — Stachorutes najtae n. sp.: A, dorsal chaetotaxy; B, ventral chaetotaxy of abdomen; C, ventral cephalic chaetotaxy; D, PAO and eyes. Abbreviations: see Material and methods. Scale bars: A-C, 50 µm; D, 10 µm.

FIG. 2. — Stachorutes najtae n. sp.: A, B, dorsal and ventral chaetotaxy of Ant. III-IV; C, chaetotaxy of Ant. I-II; D-F, chaetotaxy of femora and tibiotarsi of leg I, II and III respectively; G, chaetotaxy of furca and retinaculum; H, male genital opening; I, female genital opening. Scale bars: A-F, 10 µm; G-I, 25 µm.

FIG. 3. — Stachorutes najtae n.sp.scanning electron microscopy:A, habitus;B, PAO and eyes;C, Ant.III-IV;D, dens with mucro.Scale bars:A,100 µm;B-D,10 µm.