Pseudosinella cansiliensis, Fanciulli, Pietro Paolo & Dallai, Romano, 2008

Fanciulli, Pietro Paolo & Dallai, Romano, 2008, Three new species of Collembola from north-east Italy, Zootaxa 1701, pp. 15-28 : 23-26

Pseudosinella cansiliensis sp. nov.

Material examined. Type material. Holotype (female) and 7 paratypes (5 females, 2 males) mounted on slides. Material was collected in the Cansiglio forest; the holotype and 4 paratypes from a sample collected along the road from S. Anna to Col Indes, 24.xi.1979. Samples consisted of leaves and humus from beech wood. Three paratypes from a moss sample collected on the steep slope along the path to the locality Crosetta, 11.xi.1976. Holotype and paratypes conserved in the collembolan collection of the Department of Evolutionary Biology of the University of Siena.

Description. length 0,9–1,2 mm, habitus as in Fig. 40 A. Body pigment as minute granules scattered all over the body and particularly concentrated in the ocular plate, where 6+6 eyes are evident ( Fig. 40 B). Antennal segment ratios I:II:III:IV approximately 1:1,67:1,29:2,38; second antennal segment slightly longer than the third; ratio antenna:cephalic diagonal = 1,46. Antenna without scales with 5–6 types of setae ( Fig. 31 ). Ordinary ciliated setae (medium and long) regularly distributed on all segments. Antennal segment IV without apical vesicle and provided with numerous medium subcilindrical curved sensilla ( Figs. 31 , 40 F) and several meso-microsetae. Antennal organ III consisting of two short thick sensilla partially hidden in a small cuticular pocket; close to them, a microsensillum and 3–4 thicker sensilla are present ( Fig. 35 ); moreover, Ant. III has 2–3 short thick curved s-setae and a few subcilindrical sensilla ( Fig. 31 ). Antennal segment II with 7/8 subcilindrical and two short curved sensilla, these latter appearing striated in scanning electron microscopy ( Figs 40 G–H); moreover, a few others sligthly s-setae and microsetae are present ( Fig. 31 ). Ant. I with one microsensillum, one thick sensillum and 13/14 meso-microsetae. Clypeo-labrum with 4/5,5,4 smooth setae. Formula of the labial base: M1M2REL1L2; R is a small ciliated seta shorter than M (ratio M/R=1,8) ( Fig. 40 E). Legs without scales, claw with three teeth, the basal ones have a different size, with the posterior tooth about two times larger than the anterior one ( Figs 32 , 40 D); the unpaired tooth at 55/60% of the inner edge. Empodial appendage lanceolate and untoothed. Dorsal tibiotarsal tenent hair spatulate; ventrodistal seta smooth. Trochanteral organ consisting of 14 straight, thin, smooth and pointed setae ( Fig. 34 ). Ventral tube with 11/12 lateral-distal smooth setae ( Fig. 36 ); 12/15+12/15 anterior ciliated setae and 7/8+7/8 on the posterior side. Retinaculum with 4+4 teeth and one ciliated setae. Furca scaled in the ventral side; manubrium with 2+2 and 5/6+5/6 ventro-distal and dorso-distal ciliated setae, respectively. Many other ciliated setae of different size are scattered on the dorsal part of the manubrium. Dens with three ventral rows of ciliated setae (one internal and two external). Mucro bidentate as in Figs 37 and 40 C. Chaetotaxy of abdominal tergite II: -aBq1q2 ( Fig. 38 ). Accessory setae “s” in the anterior trichobotrial complex of abdominal tergite IV absent ( Fig. 39 ). Formula of the dorsal macrosetae: R000/00/0101+2.

Etymology. The species name is derived from the area where it was first collected: the Cansiglio Natural Reserve.

Discussion. Pseudosinella is one of the largest collembolan genera, including more than 300 species all over the world. Their diagnosis is based on several characters such as the formula of the dorsal macrochetae, the chaetotaxy of the second and fourth abdominal segment, the type and disposition of labial setae, etc ( Christiansen et al. 1983, 1990). A preliminary screening can be conducted by considering the number of ocelli in the ocular plate, that vary from 0 (blind species) to a maximum of 6 ( Christiansen et al. 1983, Gama 1984). Pseudosinella cansiliensis sp. nov. has 6 eyes, as other 29 species do. Inside this group the comparison can be limited to 7 species that appear more closely related to the new species. Most of them were originally described from caves, especially from France and Spain, and several of them show, as the new one, the same formula of dorsal macrosetae which is the following: R000/00/0101+2 ( Tab. 2 ); they are: P. luquei Beruete et al., 2002 , P. superoculata Gisin & Gama, 1969 , P. mucronata Gouze & Deharveng, 1987 , P. duodecimoculata Bonet, 1931 , P. goughi Gisin & Gama, 1972 , P. suboculata Bonet, 1931 and P. duodecimpunctata Denis, 1931 . The earliest species to be described ( P. duodecimoculata , P. suboculata and P. duodecimpunctata ) have been, more or less recently, revised by other authors ( Gisin & Gama 1970, 1972, Stomp 1986, Jordana & Baquero 2005), whose descriptions we used for a comparison. Although they share the same formula of dorsal macrosetae, specific diagnosis revealed one or more differences between P. cansiliensis sp. nov. and each one of the above-mentioned species. For instance P. luquei , P. superoculata , P. duodecimoculata , P. goughi and P. suboculata have the accessory “s” seta in the anterior trichobotrial complex of abdominal tergite IV, while this is absent in the new species. In addition P. superoculata , P. mucronata , P. goughi , P. suboculata and P. duodecimpunctata have the labial chaetotaxy with one or more smooth setae, while these are all ciliated in P. cansiliensis sp. nov. Furthermore, P. cansiliensis sp. nov. can be separated from P. duodecimoculata , P. goughi and P. superoculata for the shape of the tibiotarsal tenent hair that is spatulate in the new species, but pointed in the others. Body length is also different; P. cansiliensis sp. nov. is 0,9–1,2 mm, long while in the other species body length is greater than 1,5 mm ( Tab. 2 ).

Figures

FIGURE 40. Scanning electron microscopy of Pseudosinella cansiliensis sp. nov.: A, habitus; B, ocular plate, asterisks indicate the ocelli; C, shape of mucro; D, foot complex III; E, labium; F, subcylindrical sensilla of Ant. IV. G – H, sensilla of Ant. III.

FIGURES 31 – 39. Pseudosinella cansiliensis sp. nov.: 31, chaetotaxy of the antenna; 32, foot complex III; 33, dorsal chaetotaxy, black point macrochetae, circle pseudopores; 34, trochanteral organ; 35, antennal organ III; 36, lateral distal setae of ventral tube; 37, distal part of dens and mucro; 38, dorsal chaetotaxy of Abd. II; 39, chaetotaxy of abdominal tergite IV.