Tullbergia alcirae, Palacios-Vargas, Jose G. & Martinez, Ana E. Salazar, 2014

Palacios-Vargas, Jose G. & Martinez, Ana E. Salazar, 2014, A new species of Tullbergia (Collembola, Tullbergiidae) from Buenos Aires, Argentina, ZooKeys 416, pp. 23-30 : 24-27

Taxon classification Animalia Poduromorpha Tullbergiidae

Tullbergia alcirae sp. n. Figs 1-8

Material examined.

Type locality: Argentina: Bs As: Punta Lara, 34°48'S; 58°00'0"W, ex soil, grassland dominated by grasses ( Poaceae ) and sedge ( Cyperaceae ), May 2010. The specimens were extracted from soil samples in Berlese’s funnels. A. Salazar Martínez collector.

Holotype. Female mounted on slide. Original label: 5404/1 deposited at Colección División Entomología, Museo de la Plata. Paratypes: 2 females paratypes, 2 males paratypes, all of them mounted on slides. Original label: 5404/2-4 deposited at Colección División Entomología, Museo de la Plata. 6 females, 4 males and 11 juvenil paratypes with the same collecting data are kept at senior’s author institution with catalog number 2436.

Diagnosis.

Ant. III organ with 3 thick curved dorsal sensilla, one ventral sensillum; 6 dorsal sensilla on Ant. IV; about 72 vesicles on postantennal organ; pseudo cellar formulae 11/122/22221: one minute empodial appendix, two slightly clavate tenent hairs ventrally on each tibiotarsus.

Description.

Body length (n=12) 1.2 mm (range 0.83-1.4 mm), with moderately long macrosetae 61 µm (range 56-66), and short microsetae 18 µm (range 15-23), all of them smooth and thin. Relatively uniformly distributed fine intergumentary granules, interspersed with somewhat coarser granules on Abd. VI. Antennal bases well delimited.

Ratio head: antenna = 1: 0.8. The relative lengths of Ant. I: II; III; IV are as 1: 1.6; 1.9; 1.8. Ant. III and IV fused dorsally (80 µm). Sense organ of Ant. III with two small sensory rods concealed behind one of the two integumentary folds; in addition there are three thick sensilla clubs, which are rounded at tip; two strongly bend towards each other and not concealed by cuticule. At bases of cuticle, the third sensillum concealed by one tegumentary fold. There is a ventral straight sensillum protected by three setae longer than other ventral setae. Ant. IV furnished with 6 sensilla, 3 of them very thin and long, three thick and short, one distinct subapical pit, one microsensillum and one slightly trilobed apical bulb (Fig. 1). Postantennal organ elliptical 35 µm (range 28-51), as long as width of the Ant. I, consisting of 72 (65-86) simple vesicles lying in two regular rows (Fig. 5).

Legs chaetotaxy from I to III, coxae, 2,7,7; trochanters 5,5,5; femora, 9,9,9 (each with one ventral acuminate tenent hair); tibiotarsi (13,13,12), each with 2 ventral slightly clavate tenent hairs). Tibiotarsi short, 28 µm (range 22-31). Pretarsus with two setae each. Ungues untoothed. Empodial appendage rudimentary, in shape of a minute claw-like process (Fig. 4). Dorsal pseudocelli on the body arranged as follows: 11/122/22221. The pseudocelli are crescentic with 4-5 rows of granulations (type III of Weiner and Najt 1991).

Dorsal chaetotaxy of thorax and abdomen in Figs 5 and 8 and Table 1. Th. II and III with one lateral microsensillum on each side. Dorsal chaetotaxy of abdomen on Fig. 8. Head ventrally mainly with microsetae, three pairs of postlabial setae, posterior one is macroseta (Fig. 7). Th. II and III ventrally with one pair of setae each and four setae of different sizes on each pleural side.

Ventral tube with 6 + 6 setae (4 + 4 distal and 2 + 2 basal setae, Fig. 2). Pseudocelli of Abd. V are guarded by sensory setae similar to normal setae. Abd. IV tergite without a surrounding semicircular narrow ridge. Two anal spines relatively short, 37 µm (range 34-42) and weak, but usually slightly curved and placed on high pa pillae which touch at their bases (Fig. 8). Ratio anal spine: unguis III: 1: 1.5. Genital female plate with 3 pairs of pregenital setae, 2 pairs of circumgenital and one pair of eugenital setae. Males with 3 pairs of pregenital setae, 6 pairs circumgenital setae and 1 + 1 eugenital setae (Fig. 6).

Etymology.

The new species is named in memory of Dr. Alcira Bischoff, soil fauna researcher from Facultad de Ciencias Naturales y Museo of Buenos Aires, Argentina.

Distribution. Known only from Punta Lara, the type locality in Buenos Aires Province, Argentina.

Ecology.

Tullbergia alcirae sp. n. was found in soil samples. The specimens were taken from the first 10 cm in horizon A, with a density of 624 ± 30 individuals per m2. Fredes et al. (2009) have pointed Tullbergia sp. as a good trampling indicator in a recreation area from Miramar, Buenos Aires, Argentina. Tullbergia species in Argentina come from an extensive area with different environmental conditions but the low sampling intensity doesn`t allow to develop any biogeographic hypothesis about its distribution.

Discussion.

Tullbergia alcirae sp. n. is similar to Tullbergia paranensis because they share the presence of 3 thick curved sensilla on Ant. III, isolated by digitations of the tegumentary fold, and also by the presence of one ventral sensillum and the same shape of pseudocelli. Tullbergia alcirae sp. n. differs from Tullbergia paranensis in having more vesicles in the postantennal organ (72 vs. 30), the presence of a minute empodial appendix (versus none). It also differs in the pseudocellar formulae (11/122/22221 vs /111/11111). The number of dorsal sensilla on Ant. IV is also different (6 vs. 5). Tullbergia is supposed to have pseudocelli of type I ( Weiner and Najt 1991), but it is of type III in these two species, pointing to the need of a revision of the Tullbergiidae from Argentina.

Variation.

Tenent hairs are very slightly capitated and often leg one has one capitated and one acuminate tenent hairs.