Isotomiella uai, Mendonca, Maria Cleide de, Abrantes, Eduardo A. & Neves, Ana Carolina R., 2012

Mendonca, Maria Cleide de, Abrantes, Eduardo A. & Neves, Ana Carolina R., 2012, New species of Isotomiella Bagnall, 1939 from Southeast of Brazil (Collembola, Isotomidae), ZooKeys 233, pp. 21-30 : 25-27

Isotomiella uai sp. n. Figs 1425

Material.

Holotype: Female (2109CM/MNRJ), Southeast Brazil, State of Minas Gerais, Caeté municipality, Rain forest litter with about 1.500 meters a.s.l., 09. VII. 2011, Abrantes, EA and Silveira, TC leg.

Paratype: five females (2109CM/MNRJ) and six females (2110CM/MNRJ) same data as holotype, all material deposited in Collembola Collection of Museu Nacional da Universidade Federal do Rio de Janeiro, (Brazil).

Description.

Body length size 0,77-0,97mm. Habitus typical of the genus. Color white. Integument dorsally without craters, with primary granules. Pseudopores and integument channels not observed. Antennae subequal to head diagonal. Length of Ant I to IV (30 µm, 35 µm, 39 µm, 58 µm). Ant IV with one microsensillum protected by a curved chaeta, six small and subequal sensilla (5 µm), supplementary very thin sensilla (3-4 dorsal lateral external and one dorsal internal) (Figs 14-15). Ant III with 26 ordinary chaetae, two very small sensory rods (2 µm), three small guard sensilla (3 µm), one below short sensillum and one lateral internal additional sensillum (Fig. 14). Ant II with 23-24 smooth ordinary chaetae, two basal microsensilla (one dorsal lateral and one ventral lateral) and one microsensillum lateral external. Ant I with about 13 dorsal ordinary chaetae, two ventral and unequal sensilla (5 µm and 3 µm) and two basal microsensilla (one ventral and one dorsal). Labral chaetae pattern 4/5,5,4, four very little anterior spinules; two antero lateral chaetae of labrum (11 µm) thickened with apical filament (Fig. 16). External lobe of maxilla with bifurcate palp and 3 sublobal chaetae. All chaetae of head smooth. Axial chaetotaxy pattern from Th II to Abd IV with 8-10,5/3,3,3,3 by half tergite (Figs 17, 18). Th II with 1+1 lateral macrochaetae slightly ciliated (22 µm) and 3+3 lateral sensilla, sl 3 (5 µm) migrated far from the others two (5 µm and 3 µm); Th III with 1+1 lateral slightly ciliated macrochaetae (22 µm) and 2+2 lateral sensilla (5 µm) (Fig. 17). Abd I with 1+1 lateral slightly ciliated chaetae (17 µm) and 1+1 sensillum (4 µm); Abd II with 1+1 lateral slightly ciliated macrochaetae (22 µm), 1+1 ventral-lateral sensillum, without area devoid of chaetae (Figs 18, 19). Abd III with 1+1 slightly ciliated macrochaetae (22 µm), few slightly ciliated chaetae (18 µm) and 2+2 sensilla (5 µm), one dorso-lateral and one ventral. Abd IV with 2+2 ciliated macrochaetae (23 µm) and 1+1 ventral-lateral sensilla (7 µm). Abd V-VI with some slightly ciliated (30 µm) and some smooth macrochaetae; 1+1 dorso-lateral sensillum spl, short and thin (5 µm); 1+1 ventral sensillum sv (6 µm) and unpaired chaetae smooth, ao (15 µm), mo (19 µm) and po (20 µm) (Fig. 18).

Proximal whorl of tibiotarsi with seven chaetae (Fig. 20). Tibiotarsus III without tenent hair or thickened apical chaetae. Unguis thin and toothless (15 µm), unguiculus lanceolate (5 µm) (Figs 20, 21). Ventral tube with 3+3 anterior, 4-5 posterior and 4+4 distal chaetae (Fig. 22). Tenaculum with 4+4 teeth and one chaeta. Subcoxae anterior with seven chaetae of which one ciliated; subcoxae posterior with seven chaetae, of which one ciliated. Manubrium (55 µm) with 1+1 ventro-distal and 14+14 dorsal chaetae, without lateral chaetae (Fig. 23). Dens longer than manubrium (65 µm), slightly crenulated, with 10+10 - 13+13 anterior and 4+4 posterior chaetae. Mucro small and falcate (5 µm) (Fig. 23, 24). Female genital plate as in Figure 25.

Remarks.

Isotomiella uai sp. n.belongs to the nummulifer group sensu Kovác and Palacios-Vargas (2008) that is defined by sensillary pattern 3,2/1,1,2,1,2 from Th II to Abd IV, reduced body chaetotaxy, manubrium usually with 1+1 to 2+2 ventral chaeta, mucro usually bidentate or falcate mucro and 3 external sublobal chaetae. This new species is closest to Isotomiella fellina Mendonça & Fernandes, 2003 by its reduced general chaetotaxy and short sensilla on both antennae and tergites, but differs from it by the 1+1 ventral chaetae on manubrium, 10-13 ventral and 4 dorsal chaetae on dens and falcate mucro, against 2+2 ventral chaetae on manubrium, 19-21 ventral and 5 dorsal chaetae on dens and bidentate mucro in Isotomiella fellina . The falcate mucro of the new species is also similar to that of Isotomiella barrai Deharveng & Oliveira, 1990, Isotomiella annae Deharveng & Suhardjorno, 1994 and Isotomiella falcata Mendonça & Fernandes, 2003 and Isotomiella proxima Mendonça & Fernandes, 2003, but other characters are quite distincts. Therefore, Isotomiella uai sp.n. differs from all species of the genus by a singular set of characters, including short sensilla on both antennal IV and tergites, two anterolabral chaetae of labrum thickened and acuminate and falcate mucro.

Name derivation.

The species is dedicated to the people of Minas Gerais by the unique and local interjection “uai” used by its inhabitants.