Dinaphorura nerudai, Arbea, Javier I., 2016

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

Dinaphorura nerudai sp. nov.

Figs 27–35 ; Table 6

Type locality. Argentina, Tierra del Fuego, near Rio Grande (53º 36’ S, 68º 04’ W).

Type material. Holotype female, Tierra de Fuego, near Rio Grande, Argentina, Chiliotrichum dense scrub, with Festuca gracillima and Chiliotrichum diffusum (after Collantes et al. 1999), S.M. Bonaventura and V. Mascitti leg., February 2001. Paratypes: All specimens from same locality as holotype, 44 females, 23 males and 46 juveniles. Holotype and 10 paratypes deposited in MACN, 10 paratypes in MNCN, and 93 paratypes in JIAP.

Description. Body shape elongate. Length 1.25 mm (female holotype), 1.1–1.4 mm (female paratypes), 0.9– 1.0 mm (male paratypes). Colour white. Cuticular granulation of whole body relatively uniform but larger on posterior dorsum of Abd VI. Ungranulated cuticular ridges on dorsolateral anterior margins of Th III to Abd IV. Dorsal chaetae well differentiated into micro- and macrochaetae ( Fig. 27 ).

Antennae slightly shorter than head length ( Fig. 27 ), ratio of lengths 1:1.1. Ant I, II, and III with 7, 11, and 18 ordinary chaetae respectively. AIIIO consists of three large sensory clubs with papillate protecting integumentary fold covering two small sensory rods between two outermost of these clubs; 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; apical vesicle absent ( Fig. 32 ).

PAO elongate, consisting on about 20 simple vesicles lying in two parallel rows. Coarse secondary cuticular granules form anterior margin of PAO ( Fig. 29 ). Labial palp with only papilla B (papillae A, C, D and E absent), 6 proximal chaetae and 3 hypostomal chaetae; basal parts of labium with 4+4 and 5+5 chaetae ( Fig. 33 ). Maxillary palp simple, without sublobal hair ( Fig. 33 ).

Pso semielliptical to circular, with crescent shaped opening with five distinct ridges (type III after Weiner & Najt 1991) ( Fig. 29 ). Pso formula 11/011/11111 ( Fig. 27 ).

Dorsal chaetotaxy as in Fig. 27 . Th pleurites I, II, III with 2, 3, 3 chaetae respectively. Chaetae s on Th and Abd slightly thickened, similar in form to ordinary chaetae. Th II and III with 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 6 . Abd VI with two large, curved anal spines placed on low papillae. Ratio anal spine:claw III as 1–1.25:1. Seven spiniform processes on Abd VI, located as follows: 1+1 dorso-medial (dm), 2+2 latero-dorsal (ld) and 1 unpaired medio-ventral (mv) ( Fig. 35 ).

Ventral chaetotaxy as in Fig. 28 . 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. Chaetotaxy of anal lobes as in Fig. 34 .

Legs chaetotaxy from I to III, coxae, 3,4+7,4+7; trochanters 6,6–7,6–7; femora, 11,11,11; 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 0.15–0.25 the length of claw ( Figs 30–31 ).

Etymology. The new species is dedicated to the late Chilean poet Pablo Neruda for his 111 birthday (July 12, 1904).

Discussion. The new species belongs to the group of species with pso formula 11/011/11111, Abd VI with 7 spiniform processes and elongate PAO, D. chazeaui Weiner & Najt, 1991 , D. harrisoni Bagnall, 1948 , D. laterospina Salmon, 1941 , D. matileorum Najt, 1988 , D. pefauri Rubio & Najt, 1979 and D. spinosissima (Wahlgren, 1906) (Table 8). They differ in the number of vesicles on PAO (more than 26 vesicles in D. laterospina and D. pefauri ), the apical vesicle on Ant IV (present and conspicuous in D. laterospina , D. pefauri , D. harrisoni and D. spinosissima ) and the dorsal chaetotaxy (Table 8).

Dinaphorura najtae sp. nov.

Figs 36–43 ; Table 7

Type locality. Argentina, Tierra del Fuego, near Rio Grande (53º 36’ S, 68º 04’ W).

Type material. Holotype female, Tierra de Fuego, near Rio Grande, Argentina, Chiliotrichum dense scrub, with Festuca gracillima and Chiliotrichum diffusum (after Collantes et al. 1999), S.M. Bonaventura and V. Mascitti leg., February 2001. Paratypes: All specimens from same locality as holotype, 41 females, 7 males and 6 juveniles. Holotype and 10 paratypes deposited in MACN, 10 paratypes in MNCN, and 34 paratypes in JIAP.

Description. Body shape elongate. Length 0.7 mm (female holotype), 0.6–0.9 mm (female paratypes), 0.6–0.7 mm (male paratypes). Colour white. Cuticular granulation of whole body relatively uniform but larger on posterior dorsum of Abd VI. Ungranulated cuticular ridges on dorsolateral anterior margins of Th III to Abd IV. Dorsal chaetae well differentiated into micro- and macrochaetae ( Fig. 36 ).

TABLE 8. Main diagnοstic characters οf Dinaphorura nerudai sp. nov., Dinaphorura najtae sp. nov. and related species in the genus Dinaphorura with 11⁄011⁄11111 dοrsal psο. "?"‾‾denοtes∶ nο data available. (1) SP-Spinifοrm prοcesses οn Abd vI∶ N‾‾Τοtal number (anal spines nοt included), dm‾‾dοrsοmedial, ld‾‾laterοdοrsal and mv‾‾mediοventral prοcesses, a∶p‾‾Ratiο anteriοr∶pοsteriοr laterοdοrsal prοcesses; (2) PAΟ-Fοrm, E‾‾elοngate, Τ‾‾triangular, and Number οf vesicles; (3) Av-Apical vesicle οn Ant Iv, B‾‾bilοbed, S‾‾simple, Τ‾‾trilοbed; (4) AS ∶C-Ratiο anal spine∶claw length; (5) Dοrsal chaetοtaxy∶ m, ca, p chaetae series.

(*) Abd vI with 2 large curved anal hοrns οn papillae and nine shοrt fat spines after οriginal descriptiοn, but οnly 7 spinifοrm prοcesses are shοwn in the οriginal drawing (Fig. 134).

Antennae slightly shorter than head length ( Fig. 36 ), ratio of lengths 1:1.15. Ant I, II, and III with 7, 11, and 18 ordinary chaetae respectively. AIIIO consists of three large sensory clubs with papillate protecting integumentary fold covering two small sensory rods between the two outermost of these clubs; 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; apical vesicle absent ( Fig. 42 ).

PAO triangular, consisting on 18–20 irregularly shaped vesicles in two rows. Coarse secondary cuticular granules form anterior margin of PAO ( Fig. 43 ). Labial palp with only papilla B (papillae A, C, D and E absent), 6 proximal chaetae and 3 hypostomal chaetae; basal parts of labium with 4+4 and 5+5 chaetae ( Fig. 41 ). Maxillary palp simple, without sublobal hair ( Fig. 41 ).

Pso semielliptical to circular, with crescent shaped opening with five distinct ridges (type III after Weiner & Najt 1991) ( Fig. 43 ). Pso formula 11/011/11111 ( Fig. 36 ).

Dorsal chaetotaxy as in Fig. 36 . Th pleurites I, II, III with 2, 3, 3 chaetae respectively. Chaetae s on Th and Abd slightly thickened, similar in form to ordinary chaetae. Th II and III with 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 7 . Abd VI with two large, curved anal spines placed on low papillae. Ratio anal spine:claw III as 1–1.17:1. Seven spiniform processes on Abd VI, located as follows: 1+1 dorso-medial (dm), 2+2 latero-dorsal (ld) and 1 unpaired medio-ventral (mv) ( Fig. 39 ).

Ventral chaetotaxy as in Fig. 37 . 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. Chaetotaxy of anal lobes as in Fig. 38 .

Legs chaetotaxy from I to III, coxae, 3,4+7,4+7; trochanters 6,6,6; femora, 11,11,11; 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 0.23–0.28 the length of claw ( Fig. 40 ).

Etymology. The new species is dedicated to the late Judith Najt, a prominent Argentinean researcher of collembolan fauna, who passed away in 2014.

Discussion. The new species is most similar to D. americana Rapoport, 1962 and D. jarai Najt & Rubio, 1978 , they share the pso formula 11/011/11111 and triangular PAO (Table 8), but they differ in the number of vesicles on PAO (12–15 in D. americana , 10-11 in D. jarai vs 18–20 in the new species), the number of spiniform processes on Abd VI (5 in D. jarai vs 7 in D. americana and D. najtae sp. nov.), the apical vesicle on Ant IV (present in D. jarai and D. americana vs absent in the new species) and the dorsal chaetotaxy (Table 8).

Figures

FIGURES 27 – 31. Dinaphorura nerudai sp. nov.: 27, habitus and dorsal chaetotaxy; 28, habitus and ventral chaetotaxy; 29, PAO and antennal pso; 30 – 31, tibiotarsal chaetotaxy and claw of leg I (30) and III (31). Scales: 0.3 mm (27,28), 0.02 mm (29), 0.03 mm (30,31).

FIGURES 32 – 35. Dinaphorura nerudai sp. nov.: 32, Ant III – IV; 33, chaetotaxy of the labial complex; 34, chaetotaxy of Abd V – VI sternites; 35, chaetotaxy of Abd VI tergite. Scales: 0.03 mm (32,33), 0.05 mm (34,35).

FIGURES 36 – 37. Dinaphorura najtae sp. nov.: habitus and chaetotaxy, dorsal (36) and ventral (37). Scale: 0.2 mm.

FIGURES 38 – 43. Dinaphorura najtae sp. nov.: 38 – 39, chaetotaxy of Abd V – VI, ventral (38) and dorsal (39); 40, tibiotarsal chaetotaxy and claw of leg III; 41, chaetotaxy of the labial complex; 42, Ant III – IV; 43, PAO and antennal pso. Scales: 0.04 mm (38,39), 0.02 mm (40,41,42,43).

Tables

TABLE 6. Dinaphorura nerudai sp. nov. Dorsal chaetotaxy of adult specimens. 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	m	–	–
Abd I	m – – –	–	m	m	–	–
	p – m m	s	m	M	m	M
	a – m M	M	–	M	m	s
Abd II–III	m – – –	–	m	m	–	m
	p – m m	s	m	M	m	M
	a – m M	–	M	–	m	m
Abd IV	m m – –	m	m	M	M	–
	ca – – m	–	m	–	m	–
	p – m M	s	–	s	m	M
	a – m M	–	M	m	–	m
Abd V	m – – –	M	M	–	M	–
	p – – M	S	–	S	–	M
	a m m M
Abd VI	m m m M
	p – AS –

TABLE 7. Dinaphorura najtae sp. nov. Dorsal chaetotaxy of adult specimens. 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	m	–	–
Abd I	m	– – –	–	m	m	–	–
	p	– M m	s	m	M	m	M
	a	– M M	m	–	M	m	s
Abd II-III	m	– – –	–	m	m	–	m
	p	– M m	s	m	M	m	M
	a	– M M	–	M	–	m	m
Abd IV	m	m – –	m	m	M	m	–
	ca	– – m	m	m	–	m	–
	p	– M M	s	–	s	m	M
	a	– M M	–	M	–	m	m
Abd V	m	– – –	M	M	m	M	(m)
	p	– – M	S	–	S	–	m
	a	m M M
Abd VI	m	M M M
	p	– AS M