Tullbergia meridionalis Cassagnau & Rapoport, 1962

Arbea, Javier I., 2016, Three new species and one new record of Tullbergiidae (Collembola: Onychiuroidea) from Tierra del Fuego, Zootaxa 4093 (1) : -

Tullbergia meridionalis Cassagnau & Rapoport, 1962 nec Barra (1995)

Figs 20–26 ; Table 5

Material examined. Argentina, Tierra de Fuego, near Rio Grande, Chiliotrichum dense scrub, with Festuca gracillima and Chiliotrichum diffusum (after Collantes et al. 1999), S.M. Bonaventura and V. Mascitti leg., February 2001, 9 specimens.

Description of specimens from Tierra del Fuego. Habitus as in Figs 20–21 . Body length (without antennae) 0.50–0.62 mm. Body white. Cuticular granulation of whole body relatively uniform. Antennal bases not marked. Dorsal chaetae well differentiated into meso- and macrochaetae ( Fig. 20 ).

Antennae slightly shorter than head length ( Fig. 20 ), ratio of lengths 1:1.2. Ant I, II, and III with 7, 11, and 17 ordinary chaetae respectively. AIIIO consists of two sensory clubs (inner sensillum larger than outer one) and two small sensory rods between them; single sensillum located ventrally on Ant III. Ant IV with five thickened and curved sensilla (S1, S4, S7, S8 and S9 after D’Haese (2003) = e, c, b, a and d respectively after Rusek (1971)), one dorsoexternal microsensillum and one small subapical organite; with a small, simple apical vesicle ( Figs 22–23 ).

PAO narrow elliptical, in shallow depression, 4–5 times longer than diameter of the nearest pso, and slightly shorter than width of the Ant I, consisting of 36–52 simple vesicles lying in two parallel rows ( Fig. 25 ). Labial palp with 5 papillae A, B, C, D and E, 6 proximal chaetae and 3 hypostomal chaetae; basal parts of labium with 4+4 and 5+5 chaetae ( Fig. 24 ). Maxillary palp simple, with 1 sublobal hair.

Pso circular, stellate (type I after Weiner & Najt 1991). Pso formula: 11/111/11121 ( Fig. 20 ).

Dorsal chaetotaxy as in Fig. 20 . Th pleurites I, II, III with 2, 3, 3 chaetae respectively. Chaetae s on Th and Abd simple and slightly thickened, similar in form to ordinary chaetae. Th II and III with long, basally thickened chaeta s in position m7 and microsensillum ms adjacent to it. Abd I–IV with chaeta s in position p3. One chaeta s also present on Abd II–III as a7, on Abd IV–V as p5 and a pair lateral to genital opening. Full description of dorsal chaetotaxy is given in Table 5 Abd VI with two short, curved anal spines placed on papillae. Ratio anal spine:claw III as 0.69–0.72:1.

Ventral chaetotaxy as in Fig. 21 . Head with 3+3 postlabial chaetae. Th I–III sterna with 0,1+1, 1+1 chaetae respectively. Ventral tube with 4+4 distal and 2+2 basal chaetae. Abd V sternum with 1+1 slightly thickened chaeta s lateral to genital plate.

Tibiotarsi with 15(7+8),15(7+8),14(7+7) chaetae respectively (A1 to 7, B1 to 7 and M present, B7 absent on metatibiotarsus). Pretarsus with two chaetae each. Claw untoothed. Empodial appendage 0.2–0.23 the length of claw on leg III ( Fig. 26 ).

Remarks. Specimens from Tierra del Fuego conform to the original description by Cassagnau & Rapoport (1962) from Patagonia ( Argentina) and differ to the description by Barra (1995) from Natal, South Africa: number of vesicles in PAO: 20–22 in the specimens from Natal, 36–52 in the specimens from Tierra del Fuego, 30–50 in the types from Patagonia; tibiotarsus III with 14 chaetae in the specimens from Tierra del Fuego, 12 chaetae in the specimens from Natal; shape of PAO identical in specimens from Tierra del Fuego and Patagonia, different in the specimens from Natal; position of pso on Abd IV egal in the specimens from Tierra del Fuego and Patagonia,, different in the specimens from Natal; Ant. IV with sensilla S7 and S9 on the same level in the specimens from Tierra del Fuego and Patagonia, on the different level in the specimens from Natal; shape of guard papillae in AIIIO the same in the specimens from Tierra del Fuego and Patagonia, different in the specimens from Natal. Specimens from Natal are almost certainly a different species, closely related to T. meridionalis . The geographical distribution of these species corroborates the idea that southern South America shares a common history with the other austral areas, reflecting the existence of an ancient austral biota (Rapoport 1971).

Figures

FIGURES 20 – 21. Tullbergia meridionalis: 20, habitus and dorsal chaetotaxy; 21, habitus and ventral chaetotaxy. Scale: 0.1 mm.

FIGURES 22 – 26. Tullbergia meridionalis: 22 – 23, chaetotaxy of the antenna, dorsal (22) and ventral (23); 24, chaetotaxy of the labial complex; 25, PAO and antennal pso; 26, tibiotarsal chaetotaxy and claw of leg III. Scales: 0.03 mm (22,23), 0.02 mm (24,25,26).

Tables

TABLE 5. Tullbergia meridionalis. Dorsal chaetotaxy of adult animals. Abbreviations: m –– mesochaeta; M –macrochaeta; s (S) –– chaeta (macrochaeta) s; ms –– microsensillum; AS –– anal spines; “ – “ –– denotes absence of chaeta.

	Chaetal series	0 1 2	3	4	5	6	7
	a	a0
	d	m m	m	m	m	–	–
	sd	– m –	m	m	m	–	–
Head	oc	– m M	m	–	–	–	–
	v	– – m	m	–	–	–	–
	c	– m m	m	m	m	–	–
	p	– m m	m	m	M	–	–
	g	6 chaetae; g3 macrochaeta
Th I	m	m M	m	M	–	–	–
	a	– m M	m	–	M	m	–
Th II–III	m	– m –	–	m	m	–	S+ms
	p	– m m	M	m	M	–	–
	a	– m M	m	M	–	–	–
Abd I	m	– – –	–	m	–	–	m
	p	– m m	S	M	m	M	m
	a	– m M	m	m	m	m	s
Abd II–III	m	– – –	–	m	–	–	–
	p	– m m	s	M	m	M	m
	a	– m M	m	m	m	m	m
Abd IV	m	– – m	–	m	M	m	M
	ca	– – –	–	m	–	–	(m)
	p	– M m	s	–	s	M	M
	a	– m –	m	M	m	–	m
Abd V	m	– – –	–	m	–	–	–
	p	– – M	S	–	M	–	M
	a	M m M	m
Abd VI	m	m – M	M
	p	– AS M