Songmachilis, Zhang & Zhou, 2011

Zhang, Jiayong & Zhou, Kaiya, 2011, Descriptions of one new genus and six new species of Machilidae (Insecta: Archaeognatha) from China: morphological and molecular data, Journal of Natural History 45 (19 - 20), pp. 1131-1164 : 1137-1151

Songmachilis gen. nov.

Diagnosis

Songmachilis gen. nov. resembles Afromachilis Mendes, 1981 ( Mendes 1981) , Heteropsontus Silvestri, 1911 ( Silvestri 1911; Mendes 1990a), Metamachilis Silvestri, 1911 ( Silvestri 1936; Mendes 1990a), Paramachilis Wygodzinsky, 1941 ( Wygodzinsky 1941; Mendes 1990a), Lepismachilis s.s. Verhoeff, 1910 ( Verhoeff 1910; Mendes 1990a) and Lepismachilis (Berlesilis) Verhoeff, 1910 ( Verhoeff 1910) , but can be distinguished from them as follows. For Afromachilis : parameres on the VIIIth and IXth abdominal segments (paramere only on the IXth abdominal segment in Songmachilis ), abdominal sternites with rectangle to acute angle (abdominal sternites with obtuse angle in Songmachilis ). For Heteropsontus : parameres on the VIIIth and IXth abdominal segments (paramere only on the IXth abdominal segment in Songmachilis ), abdominal sternites with acute angle (abdominal sternites with obtuse angle in Songmachilis ). For Metamachilis : coxal stylets only on hind leg (coxal stylets on mid and hind legs in Songmachilis ), ovipositor of the secondary type (ovipositor of the tertiary type in Songmachilis ). For Paramachilis : parameres on the VIIIth and IXth abdominal segments (paramere only on the IXth abdominal segment in Songmachilis ), abdominal sternites with rectangle (abdominal sternites with obtuse angle in Songmachilis ). For Lepismachilis s.s.: parameres on the VIIIth and IXth abdominal segments (paramere only on the IXth abdominal segment in Songmachilis ), abdominal sternites with acute posterior angle (abdominal sternites with obtuse angle in Songmachilis ). For Lepismachilis (Berlesilis) : abdominal sternites with acute posterior angle (abdominal sternites with obtuse angle in Songmachilis ), two pairs of eversible vesicles (2+2 eversible vesicles) in the abdominal segments II–VI (two pairs of eversible vesicles in the abdominal segments II–V in Songmachilis ), parameres on the VIIIth and IXth abdominal segments (paramere only on the IXth abdominal segment in Songmachilis ).

0.1

BI

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ML

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MP

/

NJ

Description

Adult body length: 7.8–9.0 mm. Antennae longer than the body, distal chains with seven to nine annuli. Flagellum of antenna provided with scales. Compound eyes rounded, slightly wider than or equal to long. Paired ocelli brownish, shoe-shaped, ventral to the compound eyes. Frons swollen between the paired ocelli. Mandibles with four typical apical teeth. Thorax normal. Coxal stylets present on mid and hind legs. Spiniform setae of legs bright or black. Fore leg of male widened. Tarsal scopula absent. Abdominal segments I, VI and VII each with a pair of eversible vesicles, segments II–V with two pairs of eversible vesicles. Abdominal sternites with obtuse posterior angle. Spiniform setae present in the hind coxites. Apical spine of abdominal stylets thin and long. Paramere only on the abdominal segment IX with divisions. Penis opening large and round, subapical. Male genitalia completely covered by the IXth urosternite. Ovipositor of the tertiary type. Terminal filament and cerci without piliform scales.

Etymology

The genus is named Songmachilis for Academician Da-Xiang Song for remembering him.

Revised key of Machilidae in Mendes (1990a)

50 Two pairs of eversible vesicles in the abdominal segments II–VI........ 51

50 ′ Two pairs of eversible vesicles in the abdominal segments II–V........ 55

55 Spiniform setae present on the ventral surface of legs. Paired ocelli wider than half of the compound eyes width. P I of male swollen............ 56

56 ′ Paired ocelli light, brownish to reddish. Femur I of male with an inner field of abundant thin setae............................................ 56 ′ A

56 ′ A Parameres on the VIIIth and IXth abdominal segments.............................................................. Paramachilis Wygodzinsky

56 ′ A′ Paramere on the IXth abdominal segment........ Songmachilis gen. nov.

Songmachilis xinxiangensis sp. nov.

Males

Body length: 7.8–8.5 mm; antennae: 8.6–10.8 mm; terminal filament: 8.6–10.5 mm; cerci: 3.4–4.6 mm. Body brownish, covered densely with scales. Terga mostly covered with blackish brown scales. Terga I and IX black, and black spots present on both sides of terga III and VI. Epidermic pigment on head capsule, maxillae, legs.

Head ( Figure 3A ) brown between antennae, clypeus and labrum. Clypeus and labrum covered with numerous short, thin setae. Frons convex moderately, scaled between antennae and ocelli. Compound eyes large and black (in alcohol), contact line/length: 0.61; length/width: 1.00. Paired ocelli shoe-shaped, enlarged in ventral area; brownish (in alcohol).

Antennae longer than body length, antennal length/body length about 1.1– 1.3. Scapus, pedicellus and flagellum of antennae densely scaled. Scapus long (length/width about 1.5–1.6); pedicellus as long as wide. Colour of divisions of flagellum uniformly light-brownish, junctions between divisions pale. The distal chains ( Figure 3B ) with seven to nine annuli, which are about 1.5 times as long as wide. The distal chains with sensillum and sensorial points.

Mandibles with four typical apical teeth. Maxillary palp ( Figure 3C ) provided with numerous long setae on the ventral side. Setae in articles IV–VII denser than those in articles I–III. Articles I–VII scaled densely. External apophysis of article I cone-shaped and slightly curved backwards with long setae densely on ventral surface. Article II curved inwards, not extending beyond article III, with three to five long setae on dorsal surface and many long setae densely on ventral surface, which are as long as the width of article II. Article III with six to eight setae on dorsal surface and one blackish spine on internal distal end, and with long setae densely on ventral surface which are as long as the width of article III. Articles IV–VII with many long setae on ventral surface, and article VII cone-shaped. Dorsal surface of the articles V–VII with hyaline spines as follows: V: 6–8; VI: 15–16; VII: 12–14. Ratio of length article VII/VI: 0.76–0.80; article IV/V: 0.60–0.63.

Labial palp as in Figure 3D . Articles I–III not scaled, article III slightly swollen and obtuse angled, with sensorial cones apically. Articles I–III densely covered with light long setae, which are as long as the width of the articles.

Legs ( Figure 3E–G ) and coxal stylets scaled. Mid and hind legs (legs II–III) with coxal stylets. Femur of fore leg swollen, length/width: 1.63. Bright spiniform setae present on legs except ventral surface of femur of fore leg. The femur of fore leg with a field of dense black spiniform setae on ventral surface, but the femur of mid and hind legs without those black spiniform setae. Length of tibia I: 0.50–0.52 mm; tibia II: 0.50–0.51 mm; tibia III: 0.80 mm. Fore legs stronger than others, the tibia of hind legs obviously elongated.

Urosternites not pigmented; abdominal stylet of segments not especially elongated except IXth segment. Abdominal segments I, VI and VII each with a pair of eversible vesicles, segments II–V with two pairs of eversible vesicles. Posterior angle of sternum V obtuse (95–105 ◦); length/basal width of sternum V ( Figure 3H ): 0.35. Urosternite VII ( Figure 3I ) not swollen on its inner posterior part.

A penis and a pair of parameres with 1+7 divisions (or eight divisions) extending backward to length of the urosternite IX ( Figure 3J ). Penis normal, as long as paramere, ratio of the length of base/tip: 0.6–0.7, the opening of penis large and round, subapical. Male genitalia completely covered by the IXth urosternite. Almost three-quarters of parameres covered with thin setae, basal part of penis covered with three rows of thin setae and terminal two-thirds of penis with numerous short, thin setae. Apical spines of abdominal stylets strong. IXth coxite provided with five spines near apex. Length ratios of stylet (excluding apical spine) to coxite, V: 0.61; VIII: 0.68; IX: 0.88–0.91; length ratios of apical spine to stylet, V: 0.18–0.20; VIII: 0.2; IX: 0.11–0.13.

Terminal filament and cerci without piliform scales, with numerous scales, a few cilia and strong spines.

Females

Body length: 8.0– 9.1 mm; antennae: 8.6–11.3 mm; terminal filament: 8.0– 9.5 mm long; cerci: 4.0– 4.1 mm. Scale pattern and epidermic pigment as in male.

Head as in male ( Figure 3K ). More setae present in the labrum and the clypeus. Compound eyes large and black (in alcohol), contact line/length: 0.50–0.52; length/width: 1.00. Paired ocelli shoe-shaped, brown-reddish (in alcohol).

Antennae less robust than in male, antennal length/body length about 1.1– 1.3. The distal chains with 11–12 annuli, which are about twice as long as wide ( Figure 3L ).

Maxillary palp ( Figure 3M ) without long setae. Articles I–VII scaled densely, article I only with scales on ventral surface; dense setae on articles IV–VII, and article VII cone-shaped. Dorsal surface of the articles V–VII with hyaline spines as follows: V: 4–5; VI: 13–16; VII: 12–14. Ratio of length article VII/VI: 0.76–0.84; article IV/V: 0.60–0.63.

Labial palp without long setae ( Figure 3N ). Article I light ivory-white without scales, articles II–III with few scales, articles I–III with few short setae. Article III not swollen and nearly club in shape.

Legs ( Figure 3O–Q ) as in male. Mid and hind legs with coxal stylets. Legs and coxal stylets scaled. Femur of fore leg swollen, with bright spiniform setae on ventral surface, ratio of length to width: 1.63. Length of tibia I: 0.48–0.50 mm; tibia II: 0.50– 0.53 mm; tibia III: 0.77–0.80 mm.

Urosternites not pigmented. Abdominal stylets not elongated. Abdominal segments I, VI and VII with a pair of eversible vesicles and segments II–V with two pairs of eversible vesicles. Posterior angle of sternum V nearly obtuse (95–105 ◦); length/basal width of sternum V: 0.35. Medial posterior part of urosternite VII ( Figure 3R ) projected and swollen, exceeding posterior margin.

Ovipositor of the tertiary type, slightly exceeding beyond the stylet of urosternite IX. Gonapophysis VIII ( Figure 3S,T ) with 74 divisions with sensilla except basal 3–4 divisions. Gonapophysis IX ( Figure 3U,V ) with 64–66 divisions except the basal 23– 25 divisions with some short setae. IXth coxite provided with three to five spines near apex. Length ratios of stylet (excluding apical spine) to coxite, V : 0.60; VIII: 0.60; IX: 0.94; length ratios of apical spine to stylet, V: 0.18–0.20; VIII: 0.18; IX: 0.12–0.14.

Terminal filaments and cerci similar to those of male.

Etymology

The specific name refers to the type locality.

Coreamachilis Mendes 1991

Coreamachilis songi sp. nov.

Material examined

Holotype. NNUSB0298 , an adult male; China: Mt Yuntaishan, Lianyungang City , Jiangsu Province, on dry granite rocks covered with lichen, 34 ◦ 41 ′ N, 119 ◦ 18 ′ E, at an elevation of 100–300 m, 25 August 2005, coll. J.Y. Zhang.

Paratypes. NNUSB0299–0315 , 17 adult males ; NNUSB0316–0330 , 14 adult females; China: Mt Yuntaishan, Lianyungang City , Jiangsu Province, on granite rocks covered with lichen, 34 ◦ 41 ′ N, 19 ◦ 18 ′ E, at an elevation of 100–300 m, 25 August 2005, coll. J.Y. Zhang. NNUSB0331–0355 , 25 adult males ; NNUSB0356–0369 , 14 adult females; China: Mt Zhaoshan, Lianyungang City , Jiangsu Province, on dry rocks covered with lichen, 34 ◦ 50 ′ N, 119 ◦ 30 ′ E, at an elevation of 200 m, 20 June 2003, coll. X.M. Wen and Z. Fu NNUSB0370–0390 , 21 adult males ; NNUSB0391–0400 ; 10 adult female; China: Lianyungang City , Jiangsu Province, on granite rock, 34 ◦ 44 ′ N, 119 ◦ 18 ′ E, at an elevation of 100 m, 30 May 2004, coll. J.H. Dai.

Males

Body length: 7.0– 7.6 mm; antennae: 4.4–5.0 mm; terminal filament: 7.4–8.0 mm; cerci: 2.6–3.1 mm. Body brownish black, with black and white spots, covered densely with scales and with pigment not especially dark. Terga mostly covered with blackish brown scales. White spots present on both sides of terga II – VII. Epidermic pigment on head capsule, mandibles, maxillae, maxillary palp, labium and legs.

Head ( Figure 4A ) brown between antennae, clypeus and labrum. Clypeus and labrum covered with numerous short, thin setae. Frons convex moderately, scaled between antennae and ocelli, with two long and two short setae on frons. Compound eyes large and brownish black (in alcohol), contact line/length: 0.60; length/width: 1.00–1.08. Paired ocelli ( Figure 4A ) yellow, oval-shaped, lateral, about twice as wide as long, the distance between ocelli longer than the length of ocellus.

The antennae are shorter than body length, antennae length/body length about 0.58–0.70. Scapus, pedicellus and flagellum of antennae densely scaled. Scapus rather long (length/width about 2.00) ( Figure 4B ); pedicellus as long as wide. Colour of divisions of flagellum uniformly light-brownish, junctions between divisions pale. Division number of flagellum maximum observed 28. The distal chains ( Figure 4C ) with eight or nine annuli, each one about twice as wide as long. The distal chains with sensillum and sensorial points.

Mandibles quite robust with four typical apical teeth. Maxillary palp ( Figure 4E ) provided with numerous setae of moderate size. Setae in articles IV– VII denser than those in articles I– III. Articles II – VII scaled densely. External apophysis of article I finger-like, slightly curved backwards and small setae sparsely on ventral surface. Article II curved inwards, not extending beyond article III, with about ten to twelve light, short spines on its ventral surface. Article III with one sclerotic black spiniform short setae on ventral surface. Article IV with two or three sclerotic black spines on ventral surface and few setae on dorsal surface. Article V with dense setae onventral surface and few setae on dorsal surface. Article VI with three sclerotic black spines on ventral surface. Article VII also with three sclerotic black spines on ventral surface and article VII cone-shaped. Dorsal surface of the articles V – VII with hyaline spines as follows: V: 4–6; VI: 12–14; VII: 14–18. Ratio of length article VII / VI: 1.00; article IV/ V: 0.50.

Labial palp as in Figure 4D . Articles I– III not scaled, articles II – III with densely small and long setae; article III swollen and obtuse angle in shape, with sensorial cones apically.

Legs ( Figure 4F–H ) and coxal stylets scaled. Only hind leg with coxal stylets. Femur of fore leg obviously wider, length/width: 1.6. Femur with long spine present, black-coloured. Length of tibia I: 0.39–0.40 mm; tibia II: 0.55–0.57 mm; tibia III: 0.60–0.61 mm. Fore legs stronger than others, the tibia of hind legs obviously elongated. Number of spines on fore leg: femur 15; tibia 2; tarsus 14; on mid leg: femur 6; tibia 12–18; tarsus 16–18; on hind leg: femur 6; tibia 10; tarsus 20–24.

Urosternites not pigmented. Abdominal stylets not especially elongated except IXth segment. Abdominal segments I– VII with a pair of eversible vesicles. Posterior angle of sternum V ( Figure 4I ) obtuse (120 ◦); length/basal width of sternum V: 0.56–0.57. Urosternite VII ( Figure 4J ) not swollen on its inner posterior part.

A penis and a pair of parameres with 1+7 divisions (or 8 divisions) extending backward to the length of the urosternite IX ( Figure 4K ). Penis normal, as long as paramere, ratio of the length of base/tip: 0.5–0.6, opening of penis large and pyriform. Male genitalia completely covered by the urosternite IX. Apical spine of abdominal stylets is strong and medium-sized. IXth coxite without spines near apex. Length ratios of stylet (excluding apical spine) to coxite, V: 0.50; VIII: 0.75; IX: 1.00; length ratios of apical spine to stylet, V: 0.18–0.20; VIII: 0.14–0.15; IX: 0.11–0.12.

Terminal filament and cerci without piliform scales, with numerous scales, a few cilia and strong spine.

Females

Body length: 8.0–9.0 mm; antennae: 5.0–6.0 mm; terminal filament: 8.0–9.0 mm; cerci: 3.0– 3.5 mm. Terga mostly covered with light brown scales. No white spots present on terga. Epidermic pigment on head capsule, mandibles, maxillae, maxillary palp, labium and legs.

Head as in male ( Figure 4L ). More setae present in the labrum and the clypeus. Compound eyes large and brownish black (in alcohol), contact line/length: 0.60; length/width: 1.00–1.01. Paired ocelli as in male.

Antennae as in male ( Figure 4M ). Antennal length/body length about 0.67.

Maxillary palp ( Figure 4O ) as in male. Articles I– VII scaled densely, article I only with scales on ventral surface; articles II – VII with short setae, dense setae on articles IV– VII. Article II with about seven or eight light, short spines on ventral surface, articles VI with only one sclerotic black spine on ventral surface, article VII with no sclerotic black spine on ventral surface and article VII cone-shaped. Dorsal surface of the articles V – VII with hyaline spines as follows: V: 4–6; VI: 18–20; VII: 14–18. Ratio of length article VII / VI: 0.80–0.83; article IV/ V: 0.50.

Labium and labial palp as in Figure 4N , the labium with very diffuse pigment spots in the glossae and paraglossae. Article I not scaled, articles I– III sparsely scaled, article II with black strong setae, but rare on article I. Article III with claviform, with sensorial cones apically.

Legs ( Figures 4P–R ) as in male. Femur of fore leg not swollen, ratio of length to width: 1.95–2.0. Length of tibia I: 0.43–0.50 mm; tibia II: 0.38–0.41 mm; tibia III: 0.50–0.55 mm. Fore legs stronger than others, the tibia of hind legs not elongated. Number of spines on fore leg: femur 3; tibia 2; tarsus 10; on mid leg: femur 4; tibia 6–10; tarsus 14–16; on hind leg: femur 4; tibia 6; tarsus 15–16.

Urosternites not pigmented. Abdominal stylets not elongated. Abdominal segments different from male in number of eversible vesicles: abdominal segments I, VI and VII with a pair of eversible vesicles, and segments II – V each with two pairs of eversible vesicles. Posterior angle of sternum V ( Figure 4S ) obtuse (120 ◦); length/basal width of sternum V: 0.56–0.60. Medial part of urosternite VII ( Figure 4T ) projected and swollen, exceeding posterior margin.

Ovipositor robust, of the secondary type and exceeding half length of stylet of urosternite IX. Gonapophysis VIII ( Figure 4U,V ) with 24–25 divisions, with sensillum except basal divisions; fossorial spines present at the 7–8 apical divisions and strong setae substituted from 9–25 divisions. Gonapophysis IX ( Figure 4W,X ) with 24–26 divisions, with some short setae except the basal three divisions; fossorial claws restricted to the three apical divisions. IXth coxite without spines near apex. Length ratios of stylet (excluding apical spine) to coxite, V: 0.50; VIII: 0.74; IX: 0.56; length ratios of apical spine to stylet, V: 0.30–0.31; VIII: 0.18–0.20; IX: 0.14–0.15 .

Terminal filaments and cerci similar to those of male.

Diagnosis

A second species of genus Coreamachilis has been collected from Lianyungang City (Jiangsu Province, China), and described under the name Coreamachilis songi . This is the first discovery of a Coreamachilis bristletail from China. The species described in this paper is assigned to the genus Coreamachilis based on the following morphological points concerning females: paired ocelli ovoid, lateral, only hind leg with stylet, abdominal segments I, VI and VII with a pair of eversible vesicles, abdominal segments II – V with two pairs of eversible vesicles, and ovipositor of the secondary type. Males have not been found for Coreamachilis coreanus ( Mendes 1991) . This male is the first record of males of Coreamachilis and males of Coreamachilis were revealed to have a pair of eversible vesicles throughout abdominal segments I to VII without two pairs of eversible vesicles in abdominal segments II to V. This is a notable example in Order Archaeognatha . According to the literature, only three species with sexual dimorphism have been found ( Mendes 1990a). In analyses of COI gene sequences, monophyly of C. songi sp. nov. is well supported by neighbour joining, maximum parsimony, maximum likelihood and Bayesian inference analyses ( Figure 2 ). Although the females of C. songi sp. nov. are very similar to those of C. coreanus (only females were found) in morphology, C. songi sp. nov. is a sister group to C. coreanus in COI gene sequences analyses. We can distinguish C. coreanus from C. songi sp. nov. as follows in morphology: body length about 8.0–9.0 mm in C. songi sp. nov. (9.8–11.1 mm in C. coreanus ); annuli of the distal chains of antennae about twice as wide as long in C. songi sp. nov. (each one as wide as long in C. coreanus ); length ratio of stylet (excluding apical spine) to coxite in coxite V is 0.50 in C. songi sp. nov. (0.59–0.68 in C. coreanus ); posterior angle of sternum V nearly 120 ◦ in C. songi sp. nov. (105–110 ◦ in C. coreanus ); gonapophysis VIII with 24–25 divisions (gonapophysis VIII with 26–28 divisions in C. coreanus ) and gonapophysis IX with 24–26 divisions in C. songi sp. nov. (gonapophysis IX with 28–30 divisions in C. coreanus ); fossorial spines of gonapophysis VIII present on the 7–8 apical divisions in C. songi sp. nov. (fossorial spines of gonapophysis VIII present on the 12–13 apical divisions in C. coreanus ).

Etymology

The specific name is a patronym in honour of academician Song Da-Xiang, a famous Chinese arachnologist.

A revision of Coreamachilis

Flagellum of antenna scaled. Compound eyes rounded, not clearly longer than wide, poorly convex. Paired ocelli oval to subrectangular, lateral, their distance more than twice their own width, light coloured. Frons moderately convex between paired ocelli. Mandibles with four typical apical teeth. Maxillary palp, labium and labial palp without special characteristics. Stylet only in hind leg, well developed. Brownish spiniform seta present in the legs. Tarsal scopula absent. Abdominal segments I, VI and VII with a pair of eversible vesicles, abdominal segments II – V with two pairs of eversible vesicles in female, but abdominal segments I– VII with a pair of eversible vesicles in male. Sternum II – VII well developed, with obtuse posterior angle. Abdominal stylets not specially developed, those from the IXth coxite much more elongated, while shorter than the coxites. Apical spines of abdominal stylets short, clearly shorter than half of the stylet length. Ovipositor of the secondary type, with fossorial claws and fossorial spines in addition to the usual thin setae. A penis and a pair of parameres with 1+7 divisions (or 8 divisions). Terminal filament length equal to body length, cerci with scales, some thin cilia and a few spines present, the piliform scales absent.

Keys to species of Coreamachilis

1. Gonapophysis VIII with 24–25 divisions and gonapophysis IX with 24–26 divisions, fossorial spines of gonapophysis VIII present on the 7–8 apical divisions............................................... Coreamachilis songi sp. nov.

2. Gonapophysis VIII with 26–28 divisions and gonapophysis IX with 28–30 divisions, fossorial spines of gonapophysis VIII present on the 12–13 apical divisions................................... Coreamachilis coreanus Mendes

Subfamily PETROBIINAE Paclt 1970 Pedetontinus Silvestri 1943 Pedetontinus jiuzhaiensis sp. nov.

Material examined

Holotype. NNUSB0275 , an adult male; China: Mt Jiuzhaigou , Jiuzhaigou County, Sichuan Province, on the uppermost layer of the forest floor consisting chiefly of fallen leaves (pine) and other decaying organic matter, 33 ◦ 0 ′ N, 103 ◦ 8 ′ E, at an elevation of 1400 m, 6 August 2006, coll. J.Y. Zhang.

Paratypes. NNUSB0275–0280 , six adult males ; NNUSB0281–0285 , five adult females; same data as for holotype .

Males

Body length: 7.0–8.0 mm; antennae: 4.0–5.0 mm; terminal filament: 7.2–8.7 mm; cerci: 2.5–4.0 mm. Body brownish grey, covered densely with scales and with pigments. Terga mostly covered with light brown scales. No black-brown spots present on terga. Epidermic pigment on head capsule, mandibles, maxillae, maxillary palp, labium, labial palp and legs.

Head ( Figure 5A ) brown between antennae, clypeus and labrum. Clypeus and labrum covered with numerous short, thin setae. Frons convex moderately, scaled between antennae and ocelli. Compound eyes large and brownish (in alcohol), contact line/length: 0.50; length/width: 0.90–0.92. Paired ocelli shoe-shaped, enlarged in ventral area, brownish red (in alcohol) with white edge. Width of ocellus slightly narrower than that of compound eye (width of ocellus about 0.73–0.75 that of compound eye).

Antennae shorter than body length, antennal length/body length about 0.67– 0.70. Scapus and pedicellus of antennae densely scaled; flagellum not scaled. Scapus rather long (length/width about 1.50); pedicellus as long as wide. Colour of divisions of flagellum uniformly light-brownish, junctions between divisions pale. Divisions of flagellum maximum observed 24, proximal 12 divisions not annulated, divisions 13–16 annulated into three or four annuli, divisions 17–24 with five to six annuli. The distal chains with six annuli, each one about 1.5 times longer than wide ( Figure 5B ).

Mandibles quite robust, provided with four typical apical teeth. Maxillary palp ( Figure 5D ) provided with numerous setae of moderate size. Setae in articles IV– VII denser than those in articles I– III. Articles II – VII scaled densely. Articles IV– VII provided with numerous short setae. External apophysis of article I cone-shaped, slightly curved backwards and setae sparsely on ventral surface. Article II curved inwards, not extending beyond article III, with about three light, short spines on its ventral surface and one short spine on its dorsal surface. Article III with nine to ten spines on ventral surface. Article IV with five or six spines on ventral surface and few setae on dorsal surface. Article V with few setae on ventral surface and eight to ten spines on dorsal surface. Article VI with many setae on ventral surface and dorsal surface. Article VII with many setae on ventral surface and article VII cone-shaped. Dorsal surface of the articles V – VII with hyaline spines as follows: V: 4–6; VI: 14–16; VII: 12–14. Ratio of length article VII / VI: 0.78; article IV/ V: 0.62.

Labium and labial palp as in Figure 5C . Article I not scaled, articles II – III sparsely scaled and dense setae; article III almost club like, with sensorial cones on apical part.

Legs ( Figure 5E–G ) and coxal stylets scaled. Mid and hind legs (legs II – III) with coxal stylets. Coxal stylet with ratio in length to coxa about 0.5. Femur of fore leg not swollen, ratio of length to width: 1.66–1.67. Spines present on femur, light-coloured. Length of tibia I: 0.40–0.42 mm; tibia II: 0.42–043 mm; tibia III: 0.54–0.55 mm. Spines in legs as follows: tibia I: 0–1; tibia II: 1–2; tibia III: 4; no. 1–3 segments of tarsus I: 4, 6–8, 8; tarsus II: 4, 6–8, 8; tarsus III: 4, 6–8, 8. Fore leg stronger than others, tibia of hind leg not obviously elongated.

Urosternites not pigmented. Abdominal stylet not especially elongated except IXth segment. Abdominal segments I– VII with a pair of eversible vesicles. Sternum V with nearly right posterior angle (87–89 ◦); length/basal width of urosternite V: 0.66–0.67 ( Figure 5H ). Urosternite VII not swollen on its inner posterior part.

A penis and a pair of parameres ( Figure 5I ) with 1+5 divisions (or 6 divisions) extending backward to two-thirds of length of the urosternite IX. Penis normal, as long as paramere, ratio of the length of base/tip: 0.7–0.8, opening of penis small and apical. Male genitalia completely covered by the IXth urosternite. Apical spine of abdominal stylets strong. IXth coxite provided with six or seven spines near apex. Length ratios of stylet (excluding apical spine) to coxite, V: 0.42–0.44; VIII: 0.48–0.50; IX: 0.52; length ratios of apical spine to stylet, V: 0.50–0.52; VIII: 0.50; IX: 0.33–0.35.

Terminal filament and cerci without piliform scales, with numerous scales.

Females

Body length: 8.5–9.0 mm; antennae: 4.0– 5.5 mm; terminal filament: 8.5–9.0 mm; cerci: 4.0– 5.5 mm. Scale pattern and epidermic pigment as in male.

Head ( Figure 5J ) as in male, more setae present in the labrum and the clypeus. Compound eyes large, brownish (in alcohol), contact line/length: 0.45–0.50; length/width: 0.88–0.90. Paired ocelli brownish red, shoe-shaped, the width of ocellus slightly narrower than that of compound eye (width of ocellus about 0.73–0.75 of that of compound eye).

Antennal length/body length about 0.60. Scapus rather long (length/width about 1.50). Division number of flagellum maximum observed 25. Proximal 10 division not annulated, divisions 11–14 annulated into three or four annuli, divisions 15–18 with five or six annuli, divisions 19–25 with seven or eight annuli. The distal chains with seven or eight annuli, each one as long as wide ( Figure 5K ). The distal chains with sensilla and thin sensorial points.

Maxillary palp ( Figure 5L ) as in male. Articles II – VII scaled densely, article I only scaled on ventral surface; dense setae on articles IV– VII, and article VII cone-shaped. Dorsal surface of the articles V – VII with hyaline spines as follows: V: 4–6; VI: 16–18; VII: 16–18. Ratio of length article VII / VI: 0.84; article IV/ V: 0.66–0.68.

Labial palp as in male ( Figure 5M ). Article I not scaled, II – III sparsely scaled, I– III with dense short setae, and numerous setae of moderate-sized present in article III, less on article II but rare on article I.

Legs ( Figure 5N–P ) as in male. Femur of fore leg not swollen, ratio of length to width: 1.80. Length of tibia I: 0.47–0.50 mm; tibia II: 0.49–0.50 mm; tibia III: 0.65– 0.70 mm. Spines in legs as follows: tibia I: 1–2; tibia II: 4–6; tibia III: 4–6; number of 1–3 segments of tarsus I: 4–6, 10–14, 10–12; tarsus II: 4–6, 10–14, 10–12; tarsus III: 4–6, 10–14, 10–12.

Abdominal segments as in male. Urosternites not pigmented, abdominal stylet not elongated. Abdominal segments I– VII with a pair of eversible vesicles. Sternum V with nearly right posterior angle (87–89 ◦); length/basal width of sternum V ( Figure 5Q ): 0.66–0.67. Medial part of urosternite VII ( Figure 5R ) projected and swollen, exceeding posterior margin.

Ovipositor robust, of the tertiary type and slightly exceeding beyond the apical spine of the stylet of urosternite IX. Gonapophysis VIII ( Figure 5S–U ) with 54–55 divisions, sensilla present except 2–3 basal divisions. Gonapophysis IX ( Figure 5V–W ) with 50 divisions, basal 20–22 divisions with some short setae. IXth coxite provided with 8–10 spines near apex. Length ratios of stylet (excluding apical spine) to coxite, V : 0.49–0.50; VIII: 0.62–0.64; IX: 0.54–0.55; length ratios of apical spine to stylet, V: 0.45; VIII: 0.55–0.56; IX: 0.35–0.36.

Terminal filaments and cerci similar to those of male.

Etymology

The specific name refers to the type locality.

Figures

Figure 2. Phylogenetic tree of the relationships among 16 bristletail species based on cytochrome oxidase subunit I (COI) gene sequences. Branch lengths and topology are from the Bayesian analysis. Numbers above branches specify posterior probabilities from Bayesian inference (BI), bootstrap percentages from maximum likelihood (ML, 1000 replicates), maximum parsimony (MP, 1000 replicates) and neighbour joining (NJ, 1000 replicates) analyses.

Figure 3. Songmachilis xinxiangensis sp. nov. Male (A–J): (A) head, frontal view, (B) the distal chains of flagellum, (C) labium, (D) maxillary, (E) fore leg, (F) mid leg, (G) hind leg, (H) urosternite V, (I) urosternite VII, (J) urosternite IX with paramere and penis. Female (K–V): (K) head, frontal view, (L) the distal chains of flagellum, (M) maxillary palp, (N) labium, (O) fore leg, (P) mid leg, (Q) hind leg, (R) urosternite VII, (S) urosternite VIII, with anterior gonapophyses, (T) part of gonapophysis VIII, ventral view, (U) urosternite IX with posterior gonapophysis, (V) part of gonapophysis IX, ventral view.

Figure 4. Coreamachilis songi sp. nov. Male (A–K): (A) head, frontal view, (B) scapus of antenna, (C) the distal chains of flagellum, (D) labium, (E) maxillary palp, (F) fore leg, (G) mid leg, (H) hind leg, (I) urosternite V, (J) urosternite VII, (K) urosternite IX with paramere and penis. Female (L–X): (L) head, frontal view, (M) the distal chains of flagellum, (N) labium, (O) maxillary palp, (P) fore leg, (Q) mid leg, (R) hind leg, (S) urosternite V, (T) urosternite VII, (U) urosternite VIII with anterior gonapophyses, (V) part of gonapophysis VIII, ventral view, (W) urosternite IX with posterior gonapophysis, (X) part of gonapophysis IX, ventral view.

Figure 5. Pedetontinus jiuzhaiensis sp. nov. Male (A–I): (A) head, frontal view, (B) the distal chains of flagellum, (C) labium, (D) maxillary palp, (E) fore leg, (F) mid leg, (G) hind leg, (H) urosternite V, (I) urosternite IX with paramere and penis. Female (J–X): (J) head, frontal view, (K) the distal chains of flagellum, (L) maxillary palp, (M) labium, (N) fore leg, (O) mid leg, (P) hind leg, (Q) urosternite V, (R) urosternite VII, (S) urosternite VIII with anterior gonapophysis, (T, U) part of gonapophysis VIII, ventral view, (V) urosternite IX with posterior gonapophysis, (W, X) part of gonapophysis IX, ventral view.