Verrucoentomon montanum ( Martynova, 1970 ) Martynova, 1970

Shrubovych, Julia, 2011, Redescription of Verrucoentomon montanum new status (= Acerella montana Martynova) (Protura: Acerentomidae, Nipponentominae), Zootaxa 2743, pp. 63-67 : 63-67

Verrucoentomon montanum ( Martynova, 1970) new status

Figs. 1–20 , Table 1 .

Acerella montana Martynova 1970: 239 .

Specimens examined. Holotype female and one additional female, Inner Tian-Shan, Kyrgyzstan, 3600 m elev., high mountain plateau in the upper region of Karasai and Bol'shoj Naryn rivers, 22.07.1966, coll. P. A. Zlotin.

Head with short setae, additional setae absent, anteropseudocular (ap), postpseudocular (pp) and lateral (ls) setae present; labrum slightly protruded ( Figs. 1, 2 ). Setae of hind margin of head slightly differentiated, their length ratio 1: 2: 3 as 1.4: 1.7: 1. Pseudoculus abbreviated, with distinct posterior projection, PR = 22 ( Fig. 7 ). Maxillary gland with small, distinctly granulated calyx, long posterior filament and distinct posterior dilation, CF = 5.6 ( Fig. 8 ). Maxillary palps with slender subequal sensilla; labial palps with terminal tuft and broad sensillum ( Figs. 5, 6 ). Granulation on inner margin of labium not visible in holotype, but in other female distinct granulation present.

Nota with short setae; accessory setae P1a and P2a very short, sensillum-like ( Fig. 3 ), P3a distinctly longer and setiform ( Fig. 20 A). Pronotal seta 2 nearly equal in length with seta 1. Setae M short, thin. Length ratio of mesonotal setae P1: P1a: P2 as 6.7: 1: 9.3. P2a situated nearer to P3 than to P2. Seta M2 on prosternum absent; A2 on thoracic sternites short, sensillum-like ( Fig. 20 E); other setae of normal shape. Meso- and metanotum with pores sl and al. Thoracic sternal pores not seen.

Foretarsus without sensillum b'; sensillum t1 filiform, short; a, b, g and a' linear, g the thickest ( Figs. 10, 11 ). Sensilla c and e strongly broadened, short; d, f, t2 and c' thin, nearly seta-like; t3 very small, leaf-like. Sensillum d situated closer to e than to c; a' slightly distal to level of t2 insertion. Relative lengths of sensilla: t3 <e <(t1 = c) <(d = g = a') <c'<a <(b = t2) <f. Seta β 1 slightly shorter than δ 1 and setiform, δ 4 distinctly shorter than δ 1 and blunt. Claw relatively short, without inner tooth, empodial appendage short. BS = 0.7, TR = 3.4, EU = 0.2.

Seta P4 on tergite I short ( Fig. 20 B). Accessory setae on tergites I–VI longer than those on nota, thin, longest on tergite VII ( Figs. 20 C, D). Pores psm present on tergites I–VIII, al on tergites II–VII; pores psl weakly visible, present on tergite VII ( Figs. 13–15 ).

Abdominal legs with 4, 2, 2 setae. Subapical seta on second and third pairs of abdominal legs slightly longer (19 µm) than apical seta (15 µm) ( Fig. 12 ).

Sternal accessory setae on sternites I–VII slightly shorter than those on tergites ( Figs. 20 F, G). Sternite I with pair of anterolateral single pores ( Fig. 12 ). Pores not observed on sternites II–VI; sternite VII with simple median pore near hind margin of tergite, anterior to Pc seta ( Figs. 17, 18 ).

Dorsal Ventral Setae Formula Setae Formula

Th. I 1, 2 4 A1, 2, M1 4+2 (Ac)—absent in holotype

Abdominal segment VIII with row of distinct denticles on tergite and two irregular rows on sternite ( Figs. 15, 19 ). Striate band well developed. Comb VIII with concave hind margin composed of 12 slender teeth ( Fig. 4 ). Pores psm without or with single accompanying tooth. Hind margin of laterotergites and sternite smooth. On tergite IX setae 1 and 1a of equal length. Seta 2a on tergites IX and X shorter than other setae. Posterior margin of segments X and XI with fine serration. Medial pore on dorsal lobe of telson and pair of anterolateral pores on ventral lobe present. Female squama genitalis with broad, blunt acrostyli ( Fig. 9 ).

Body chaetotaxy as in Table 1 . Seta Ac on sternite II absent in holotype, present on other specimen.

Body measurements (2 females) (in µm): head 145; pseudoculus about 6.5; posterior part of maxillary gland 23–26; seta 1 on posterior margin of head 12–13, seta 2 16, seta 3 9–10; pronotal seta 1 18, seta 2 14; mesonotal seta P 1 14–16, seta P1a about 2.5, seta P 2 23– 24, seta M 9–10; foretarsus 94–96; claw 26–28; empodial appendage 4.

Relationships. According to Szeptycki (2007) the species Acerella montana Martynova, 1970 is placed in subfamily Acerellinae as species “incertae sedis.” This species is transferred to Verrucoentomon Rusek, 1974 ( Acerentomidae , Nipponentominae ) on the basis of the following characters: abdominal legs with two nearly equal setae, posterior position of seta P3 on abdominal tergites, three pairs of A -setae on meso- and metanotum, shape of maxillary gland with racemose surface of calyx and without wide racemose appendices, filiform foretarsal sensillum t1 and leaflike t3, the position of sensillum d nearly to e and position of a’ distally to t2 on foretarsus, β 1 setiform, and δ 4 short and blunt showed. Verrucoentomon montanum shares the peculiar pattern of foretarsus (short and broad sensilla c and e) not only with two other species of Verrucoentomon (V. a u r i f e r Szeptycki, 1988 and V. yushuense Yin, 1980 ) but also with Nienna parvula Szeptycki, 1988 , N. quinghaiensis Bu & Yin, 2008 and Huashanentulus huashanensis Yin, 1980 ( Szeptycki 1988, Yin 1980, Bu & Yin 2008, 2010).

Huashanentulus Yin, 1980 , characterized by possession of a maxillary gland of the Acerentulus - type, seta P3 on abdominal tergites situated in anterior position and only two (A2 and A4) anterior setae on nota, probably is unrelated to V. montanum .

In the body chaetotaxy and the porotaxy of abdominal sternites V. montanum is very similar to N. parvula . However, V. montanum differs from N. parvula in some important characters: shape of maxillary gland (uniform with other Verrucoentomon species in V. montanum and relatively smaller with simple calyx in Nienna parvula ) and shape of sensillum t3 on foretarsus (leaf-like in V. montanum , globular in N. parvula ), as well as some less prominent differences, for example, the position of sensilla b, c and d (in the former b is situated on same level as c; d is not so near to e, b is relatively shorter and thicker). Verrucoentomon montanum is very similar to N. quinghaiensis in the identical chaetotaxy of the tergites, sternites and foretarsi. Only a few straightforward differences can be found between the two species: N.

quinghaiensis possesses additional setae on head, has longer foretarsal sensilla a and b but shorter foretarsus and claw (70 and 20 µm respectively); head setae appear to be shorter (Bu & Yin 2008, p. 205, fig.14); ratio of setae on mesonotum P1: P1a: P2 as 4: 1: 6; pores psl absent on tergites and sternal pores absent; female squama genitalis with short pointed acrostyli. As the result of this study, N. quinghaiensis appears to differ more from N. parvula than from V. montanum .

Nanshanentulus urumchiensis Bu &Yin, 2007 and Nosekiella sinensis Bu &Yin, 2008 are characterized by short and broadened foretarsal sensilla c and e, but their shapes are nearly claviform, not as broad as in V. montanum . In addition, these two species are characterized by the claviform shape of sensillum t1.

Within Verrucoentomon the redescribed species differs from V. a u r i f e r in the absence of P2a' on nota and the absence of P1a on abdominal tergites I–VI. Accessory setae in the latter species are distinctly longer than in the former. Verrucoentomon aurifer is characterized by a different shape of foretarsal sensillum e (broadened only in distal part) and g (slender and about twice longer), and very long sensillum c ’. In V. aurifer the medial pore on sternite VII is near the anterior margin of the segment, whereas in V. montanum it is located posteriorly.

Verrucoentomon montanum shares the body chaetotaxy, shape of accessory setae and the general pattern of foretarsus with V. y u s h u e n s e Yin, 1980. Sensilla c and e in V. y u s h u e n s e are thinner and relatively shorter, and sensillum a' is situated more distally, than in V. montanum . Acrostyli of V. y u s h u e n s e are conical in shape, not broad as in V. montanum . In the lateral region of tergites IX–X distinctly ciliated lines are present in V. yushuense and absent in V. montanum .

Figures

FIGURES 1 – 11. Verrucoentomon montanum (Martynova, 1970). 1 — rostrum, dorsal view; 2 — head (ap = anteropseudocular, pp = postpseudocular, ls = lateral setae); 3 — pro-, meso and metanotum; 4 — comb of tergite VIII; 5 — maxillary palp; 6 — labial palp; 7 — pseudoculus; 8 — canal of maxillary gland; 9 — female squama genitalis; 10 — foretarsus, exterior view; 11 — foretarsus, interior view (magnify as Fig. 10). Arrows show pores. Fig. 4 — additional female, others—holotype. Scale bars: 20 µm.

FIGURES 12 – 20. Verrucoentomon montanum (Martynova, 1970) 12 — stergites I and II with abdominal legs; 13 — tergite I; 14 — tergites VI and VII, right side; 15 — tergites VII – XI & telson, right side; 16 — pro- and mesosternum; 17 — sternite VI; 18 — sternite VII; 19 — sternites VIII—XI & telson; 20 — setae P 3 a on metanotum (A), P 4 on tergite I (B), P 2 a on tergites VI and VII (C and D), A 2 on prosternum (E), P 1 a on sternites VI and VII (F and G). Arrows show pores. Figs. 14 and 15 — additional female, others—holotype. Scale bars: 20 µm.

Tables

TABLE 1. Body chaetotaxy of Verrucoentomon montanum (Martynova, 1970)

Th. II	A2, 3, 4, M	8	P1, 2, 3 Ac, 2, 3, M	6 5+2
Th. III	P1, 1a, 2, 2a, 3, 3a, 4, 5 A2, 3, 4, M	16 8	P1, 3 Ac, 2, 3, 4, M	4 7+2
Abd. I	P1, 1a, 2, 2a, 3, 3a, 4, 5 A1, 2, 5	16 6	P1, 3 Ac, 2	4 3
Abd. II	P1, 2, 2a, 3, 4 A1, 2, 3, 4, 5	10 10	P1, 1a (Ac), 2	4 3
Abd. III	P1, 2, 2a, 3, 4, 4a, 5 A1, 2, 3, 4, 5	14 10	Pc, 1a, 2 Ac, 2	5 3
And. IV-VI	P1, 2, 2a, 3, 4, 4a, 5 A1, 2, 3, 4, 5	14 10	Pc, 1a, 2 Ac, 1, 2	5 3
Abd. VII	P1, 2, 2a, 3, 4, 4a, 5 A2, 3, 4, 5	14 8	P1, 1a, 2, 3 Ac, 2	8 3
Abd. VIII	P1, 1a, 2, 2a, 3, 4, 4a, 5 A1, 4, 5	16 6	Pc, 1, 1a, 2, 3 1, 2	9 4
Abd. IX Abd. X Abd. XI Telson	Pc, 1, 1a, 2, 2a, 3, 3a, 5 1, 1a, 2, 2a, 3, 4 1, 2, 2a, 3, 4 1, 3, 4	15 12 10 6 9	1a 1, 2 1, 2	2 4 4 6 6