Acerentulus shrubovychae, Galli, Loris & Capurro, Matteo, 2013

Galli, Loris & Capurro, Matteo, 2013, Acerentulus shrubovychae sp. nov. from Italy (Protura: Acerentomidae), Zootaxa 3609 (4), pp. 431-436 : 431-436

Acerentulus shrubovychae sp. nov.

Figures 1 –20, Tables 1 , 2

Type material. Holotype male from a mixed forest of Testa d’Alpe, Valle della Serra (1165 m elev.), 43°55’N 7°34’E, Rocchetta Nervina, Ligurian Alps, northwestern Italy, August 2009, coll. Matteo Capurro; 4 male, 17 female, 5 pre-imago, 3 maturus junior paratypes from the same locality as the holotype, August and October 2009. Type specimens are deposited in the Genoa Natural History Civic Museum (MSNG).

Diagnosis. Foretarsal sensillum a reaching the base of d, b and c subequal in length, e short slightly surpassing the base of g, f slightly nearer to e than to g, apices of both f and g surpassing base of tarsus, f longer than g, c' long and thin, its apex surpassing base of tarsus. Tergites II–V with 8 anterior setae (A1, A2, A4 and A5) and missing setae P1a, P3 and P3a; A1 and P1a absent on tergite VII. Connecting line on sternites IV–VI only barely visible in few specimens or generally absent. Pores absent on meso- and metasternum and sternite I; asymmetrically situated pore on sternites II and III; groups of pores on sternite VI. Female squama genitalis with long pointed acrostylus.

Description. Body length of males 1211 ± 77 μm (range: 1120–1310; n = 5), female length 1326 ± 39 μm (range: 1260–1390; n = 8).

Head of male 119 μm long in dorsal view (113–125; n = 2), that of female 124 μm long in dorsal view (range: 121–129; n = 3); setae sd4 and sd5 present, seta d6 (Rusek et al. 2012) absent ( Figs. 1 .A–1.B). Single median pore anterior to the level of the pseudoculi ( Fig. 1 .A–1.B). Rostrum protruded. Pseudoculus almost circular, diameter 9.0 μm (range: 8.5–10; n = 12), longitudinally divided ( Fig. 2 ); PR = 12.1 (range 10.6–13.4, n = 5). Canal of maxillary gland simple ( Fig. 3 ), the proximal part 25 μm long in males (range: 22.0–27.5; n = 5) and 27.5 μm long in females (range: 25–31; n = 8), with distinct tripartite posterior dilation, CF = 4.5. Maxillary palpus with two sensilla, both seta-like ( Fig. 4 ). Labial palpus with apical tuft of setae and slender sensillum ( Fig. 5 ).

Foretarsus length 91.4 μm (range: 87–99; n = 13), claw 24.5 μm (range: 22–28; n = 11), without inner tooth or outer flap, TR = 3.7 (range 3.3–4.0; n = 1); empodium length 6.9 μm (range: 6–9, n = 9), EU = 0.28 (range 0.22–0.35, n = 9); S-shaped seta as long as claw, 24.3 μm (range: 22–27; n = 9). Sensillum t1 claviform, BS = 0.35 (range 0.34–0.37, n = 13); t2 thin, t3 shaped like a willow leaf. Sensillum a reaching base of d; sensillum b long, subequal to c in length, base at same level as that of c; apices of b and c reaching base of γ 3, b and c close to each other; tip of sensillum d between bases of e and f; e slightly surpassing the base of g; base of sensillum f slightly closer to e than to g, apices of f and g reaching base of claw; f longer than g. Sensillum a' broad and distal to t1, short, not reaching base of t2; b' thin, just reaching base of c'; c' thin, its apex reaching base of claw. Ventral seta β 1 and interior seta δ 4 subequal; δ 4 situated proximally to c’ ( Figs. 6–7 ). Foretarsal pores present near sensillum c and between g and t3 ( Fig. 6 ). Middle tarsus length 35.3 μm (range: 35–36; n = 3) in males and 36.5 μm (range: 35–38; n = 6) in females; claw length 17.6 μm (range: 16–19; n = 9). Hind tarsus length 39.7 μm (range: 39–40; n = 3) in males and 41.8 μm (range: 39–44; n = 6) in females; claw length 19.2 μm (range: 17–21; n = 9). Single glands originating in femora visible in middle and hind legs.

Chaetotaxy given in Table 1 . Thoracic tergite I with two pairs of setae. Thoracic tergites II–III ( Fig. 8 ) each with two pairs of dorsal anterior setae (A2, A4); setae P2a nearer to P3 than to P2. Seta P5 very short. Length ratio of setae P1: P2 on mesonotum as 1:1.3 (range 1.2–1.5, n = 12). Tergite I with three pairs of anterior setae (A1, A2, A5); seta A5 very short; setae P1a, P3a, P4a and P5 absent. Tergites II–VI each with four pairs of anterior setae (A1, A2, A4, A5), with seta A4 posterior to the others; setae P1a and P3a absent, seta P4a nearer to P5 than to P4. Setae P3 absent on tergites II–V. Setae P3 on tergite VI anterior to the posterior row. Tergite VII (Fig. 10) with 3 pairs of anterior setae (A2, A4, A5); P3a present. Tergite VIII with 3 pairs of anterior setae (A1, A4, A5); P1a present, P4 and P4a absent. Setae P2a on tergites VI–VIII very short, close to P2. Tergites IX and X with 12 setae; tergites XI and XII with 6 and 9 setae, respectively (Fig. 12). Mesosternum formula typically 5 + 2 / 4 (Ac, A2, A3 + M / P2, P3) ( Fig. 9 ). Sternites I–VII with 3 anterior setae (Fig. 11); sternite VIII with 4 anterior setae and 2 posterior setae; sternites IX–X with 4 setae; sternites XI–XII with 6 setae (Fig. 13). Setae A2 on sternites II–III very short.

Chaetotaxic variability: presence of a third asymmetrical seta on thoracic tergite I (one adult); asymmetrical absence of seta P1 on tergite I (one adult); asymmetrical presence of a doubled seta A2 on tergite II (one adult); one P1 seta on tergite V shifted forward and laterally with respect to P1a (one adult); asymmetrical absence of seta A2 on tergite VII (one pre-imago); asymmetrical absence of seta P3a on tergite VII (one maturus junior); presence of a P0 seta on tergite VIII instead of setae M1 (formula: 6/15) (two adults); absence of seta Mc on tergite VIII (formula: 6/14) (one maturus junior); asymmetrical presence of a supernumerary posterior seta medial to P1 on tergite VIII (one adult); presence of a supernumerary asymmetrical seta between A2 and P1a on sternite I (one adult); asymmetrical presence of a supernumerary anterior seta externally to A2 (one adult); asymmetrical absence of seta A2 on sternite IV (one pre-imago); asymmetrical absence of seta P1 on sternite IV (two adults); asymmetrical absence of seta P3 on sternite IV (one adult); asymmetrical absence of seta P1a on sternites V and VI (one adult each); one P1 seta shifted externally to P1a and a bit away from the hind margin on sternite V (one adult); presence of a supernumerary asymmetrical seta between Ac and A2 on sternite VI (one adult); asymmetrical presence of seta A3 on sternite VI (one adult); presence of an A0 seta on sternite VIII rather than an A1 pair (formula: 3/2) (one adult).

Porotaxy given in Table 2 . Thoracic sternites without pores. Sternites II and III with an asymmetrical psm pore between Pc and P1a. Sternite VI with two groups of psm pores (1–3) symmetrically placed anterior to P1. Sternite VII with a posterocentral pore (pc) near its hind margin, between P1 setae.

Connecting lines on anterolateral corners of sternites IV–VI weakly visible in few specimens or absent. Abdominal appendages II and III each with three setae (Fig. 14). Granular latero-dorsal area on tergite VI with a “milk bottle” shape (Fig. 11). Striate band on Abd. VIII well developed, with distinct striae (Figs. 12–13); comb with about 10–12 slender teeth (Fig. 15). Irregular row of minute granules just posterior to the striate band. Male squama genitalis with 6 + 6 setae (Fig. 16). Female squama genitalis with long, pointed acrostylus (Fig. 17).

FIGURES 10–20. Acerentulus shrubovychae sp. nov. 10) Tergites VI–VII. 11) Sternites VI–VII. 12) Tergites VIII–XII. 13) Sternites VIII–XII. 14) Abdominal appendage II. 15) Comb on abdominal tergite VIII. 16) Male squama genitalis. 17) female squama genitalis. 18) Preimago squama genitalis. 19) Foretarsus of maturus junior, exterior view. 20) Foretarsus of maturus junior, interior view. Arrows indicate pores. Figs. 10–14, 16: holotype; Figs. 15, 17–20: paratypes.

Imago Pre-imago Maturus Junior Pre-imago. Length of body 1027 μm (range: 960–1065; n = 5), foretarsus length 77 μm (range: 74–79; n = 4), TR = 3.8–4.0, BS = 0.32–0.38. Squama genitalis short, with 6 + 6 setae, as shown in Fig. 18. Chaetotaxy (Table I) and porotaxy (Table II) identical to those of adults.

Maturus junior. Length of body 1023 ± 67 μm (range: 980–1100; n = 3), foretarsus (Figs. 19–20) length 70 ± 4.6 μm (range: 66–75; n = 3), TR = 3.1–3.4. Chaetotaxy (Table I) differing from that of adults in absence of seta P3 on tergite VI, presence of a single Mc seta on tergite VIII, absence of setae P1a and P2a on tergite X, absence of setae 1 and 3 on sternite XI. Porotaxy (Table II) same as in adults.

Ethymology. This species is dedicated to Dr. Julia Shrubovych.

Remarks. Acerentulus shrubovychae sp. nov. is similar to A. gisini Condé, 1952 in the chaetotaxy, but in A. gisini foretarsal sensillum a is longer (reaching seta γ 3) and the female squama genitalis is tripartite. The maxillary gland of the new species and the chaetotaxy are similar to those of A. alpinus Gisin, 1945 , but foretarsal sensilla a and a’ are longer in A. alpinus . The porotaxy of A. shrubovychae sp. nov. differs from that of other Acerentulus spp. for which the porotaxy has been described.

*we suggest the denomination “anterocentral” ac and “anterolateral” al for these pores, respectively.

Figures

FIGURES 1 – 9. Acerentulus shrubovychae sp. nov. 1 A) Head, dorsal view. 1 B) Head, lateral view. 2) Pseudoculus. 3) Canal of maxillary gland. 4) Maxillary palpus. 5) Labial palpus. 6 A) Foretarsus, exterior view. 6 B) Foretarsus, exterior view. 7) Foretarsus, interior view. 8) Mesonotum. 9) Mesosternum. Arrows indicate pores. Figs. 1 A, 2, 6 A, 8, 9: holotype; Figs. 1 B, 3 – 5, 6 B, 7: paratypes.

Tables

TABLE 1. Chaetotaxy of Acerentulus shrubovychae sp. nov.

	Formula	Complementary setae	Formula	Complementary setae	Formula	Complementary setae
Dorsal
Thorax I	4	1, 2	4	1, 2	4	1, 2
II–III	6/16	A2, 4, M P1, 1a, 2, 2a, 3, 4, 4a, 5	6/16	A2, 4, M P1, 1a, 2, 2a, 3, 4, 4a, 5	6/16	A2, 4, M P1, 1a, 2, 2a, 3, 4, 4a, 5
Abdomen I	6/10	A1, 2, 5 P1, 2, 2a, 3, 4	6/10	A1, 2, 5 P1, 2, 2a, 3, 4	6/10	A1, 2, 5 P1, 2, 2a, 3, 4
II–V	8/12	A1, 2, 4, 5 P1, 2, 2a, 4, 4a, 5	8/12	A1, 2, 4, 5 P1, 2, 2a, 4, 4a, 5	8/12	A1, 2, 4, 5 P1, 2, 2a, 4, 4a, 5
VI	8/14	A1, 2, 4, 5 P1, 2, 2a, 3, 4, 4a, 5	8/14	A1, 2, 4, 5 P1, 2, 2a, 3, 4, 4a, 5	8/12	A1, 2, 4, 5 P1, 2, 2a, 4, 4a, 5
VII	6/16	A2, 4, 5 P1, 2, 2a, 3, 3a, 4, 4a, 5	6/16	A2, 4, 5 P1, 2, 2a, 3, 3a, 4, 4a, 5	6/16	A2, 4, 5 P1, 2, 2a, 3, 3a, 4, 4a, 5
VIII	6/16	A1, 4, 5, M1 P1, 1a, 2, 2a, 3, 3a, 5	6/16	A1, 4, 5, M1 P1, 1a, 2, 2a, 3, 3a, 5	6/15	A1, 4, 5, Mc P1, 1a, 2, 2a, 3, 3a, 5
IX	12	1, 1a, 2, 2a, 3, 4	12	1, 1a, 2, 2a, 3, 4	12	1, 1a, 2, 2a, 3, 4
X	12	1, 1a, 2, 2a, 3, 4	12	1, 1a, 2, 2a, 3, 4	8	1, 2, 3, 4
XI	6	1, 3, 4	6	1, 3, 4	6	1, 3, 4
XII	9		9		9
Ventral
Thorax I	(4+4)/6	A1, 2, M1, 2 P1, 2, 3	(4+4)/6	A1, 2, M1, 2 P1, 2, 3	(4+4)/6	A1, 2, M1, 2 P1, 2, 3
II	(5+2)/4	Ac, 2, 3, M P2, 3	(5+2)/4	Ac, 2, 3, M P2, 3	(5+2)/4	Ac, 2, 3, M P2, 3
III	(7+2)/4	Ac, 2, 3, 4, M P2, 3	(7+2)/4	Ac, 2, 3, 4, M P2, 3	(7+2)/4	Ac, 2, 3, 4, M P2, 3
Abdomen I	3/4	Ac, 2 P1, 1a	3/4	Ac, 2 P1, 1a	3/4	Ac, 2 P1, 1a
II–III	3/5	Ac, 2 Pc, 1a, 2	3/5	Ac, 2 Pc, 1a, 2	3/5	Ac, 2 Pc, 1a, 2
IV–VII	3/8	Ac, 2 P1, 1a, 2, 3	3/8	Ac, 2 P1, 1a, 2, 3	3/8	Ac, 2 P1, 1a, 2, 3
VIII	4/2	A1, 2 P1a	4/2	A1, 2 P1a	4/2	A1, 2 P1a
IX–X	4	1, 2	4	1, 2	4	1, 2
XI	6	1, 2, 3	6	1, 2, 3	2	2
XII	6		6		6

TABLE 2. Porotaxy of Acerentulus shrubovychae sp. nov.

	Imago		Pre-imago	Maturus Junior
	Formula	Pores	Formula Pores	Formula Pores
Dorsal
Thorax I	0		0	0
II	2 + 2	al, l	2 + 2 al, l	2 + 2 al, l
III	1 + 1	l	1 + 1 l	1 + 1 l
Abdomen I	1 + 1	psm	1 + 1 psm	1 + 1 psm
II–V	2 + 2	psm, al	2 + 2 psm, al	2 + 2 psm, al
VI–VII	3 + 3	psm, psl, al	3 + 3 psm, psl, al	3 + 3 psm, psl, al
VIII	1 + 1	psm	1 + 1 psm	1 + 1 psm
IX–XI	0		0	0
XII	1	ac	1 ac	1 ac*
Ventral
Thorax I–III	0		0	0
Abdomen I	0		0	0
II–III	1 + 0	asymm. psm	1 + 0 asymm. psm	1 + 0 asymm. psm
IV–V	1 + 1	psm	1 + 1 psm	1 + 1 psm
VI	n + n	psm	n + n psm	n + n psm
VII	1	pc	1 pc	1 pc
VIII–XI	0		0	0
XII	1 + 1	al	1 + 1 al	1 + 1 al*