Machilontus, Silvestri, 1912

Song, Zhi-Shun, Mendes, Luis F. & Huang, Fu-Sheng, 2012, A Review Of Microcoryphia Fauna From Vietnam, With New Subgenus, New Species Of Machilontus Silvestri (Machiloidea: Meinertellidae), And New Data For Sexual Dimorphism In The Order, Raffles Bulletin of Zoology 60 (2), pp. 313-327 : 315-320

Machilontus (s. str.) phami, new species

( Figs. 2 A–K, 3A–F, 4A–G, and 5A–J)

Material examined. — Holotype. male, Vietnam: Ninh Binh, Cuc Phuong National Park (20°20'56.6"N, 105°36'02.4"E), natural forest, 408 m, canopy fogging, coll. D. S. Pham, G. Zheng & S. Q. Li, 21 Jul.2008 ( IZCAS) . Paratypes. 2 females, same data as holotype ; 2 females, Vietnam: Vinh Phuc, Tam Dao National Park (21°30'36.4"N, 105°33'48.9"E), shrub land, 440 m, canopy fogging, coll. D. S. Pham, G. Zheng & S. Q. Li, 27 Jul.2008 ; 1 male, 2 females, Vietnam: Hai Phong, Cat Ba National Park (20°48'25.8"N, 107°00'58.1"E), natural forest, 24 m, canopy fogging, coll. D. S. Pham, G. Zheng & S. Q. Li, 15 Jul.2008 (all in IZCAS) .

Diagnosis. — Lateral ocelli with a small dark patch on inner edge. Frons without V-shaped stripes above median ocellus. Antennae very long, more than three times longer than body length; scapus with a long dark stripe on inner and outer surfaces. Maxillary palps as follows: article I with dorsal triangular process elongate, as long as the maximum diameter of article I; article II in males with dorsal hook-like process relatively short and small, incurved internally and ventrally; articles VI and VII respectively with 18–20 and 41–43 hyaline spines from base to apex along dorsal surface in males and 22–28 and 32–38 in females. Legs with pigmented stripes on femora and tibiae. Penis relatively big, nearly as long as half of coxites IX. Ovipositor tertiary type, slightly extended beyond terminal spines of stylets IX.

Description of males. — Body length (from apex of head to tip of abdomen) 9.4–9.7 mm; maximum antennae length 34.4 mm; cerci length 12.9 mm; caudal filament incomplete, not measured. Scale pattern unknown. General colour with dark brown dense scales. Head and appendages devoid of scales, with dark brown or violet-brown epidermic patches or stripes ( Fig. 2A ).

Compound eyes black, large and convex, with ratios of length to width 0.86–0.87 and line contact to length 0.50–0.57 ( Fig. 2B, C ). Lateral ocelli reddish, with a small dark pigmented patch on inner edge; ocelli long sole-shaped, more or less constricted in middle, the outer area slightly wider than the inner one, nearly 3.5 times as wide as its length ( Fig. 2B ). Frons with a small dark patch and several setae between lateral ocelli and a relatively large dark spot on inner base of antennae ( Fig. 2C ).

Antennae very long, the maximum length more than three times longer than body length ( Fig. 2A ); scapus about 2.5 times as long as its width, with a long dark stripe on inner and outer surfaces, respectively ( Fig. 2C, E ).

Mandible with four distinct teeth in incisor portion ( Fig. 2D ). Maxillary palps as follows ( Fig. 2F, G ): article I with dorsal triangular process elongate, as long as the maximum diameter of article I, two small inner processes above dorsal process and a small process on inner apex; article II with dorsal hook-like process relatively short and small, incurved internally and ventrally, with some black strong setae on dorsal base; article III with dense black strong setae on inner surface; article IV with distinct preformed breaking point at base; articles IV–VII slender than proximal articles; article V with dense black strong setae on ventral surface and with 1–3 hyaline spines near dorsal apex; articles VI and VII with 18–20 and 41–43 hyaline spines from base to apex along dorsal surface, respectively; distal article distinctly elongate, with ratio of length of articles VII: VI: V = 1: (0.71–0.77): (0.80–0.89). Distributions of pigmented patches of maxillary palps on inner surface as in Fig. 2F and on outer surface as in Fig. 2G .

Labium with some dark strong setae on base ( Fig. 2H ). Labial palps with distal article clavate and slightly expanded apically, with numerous sensory cones.

Legs with fore coxae, femora and tibiae slightly thicker than middle and hind ones; hind tibiae longer than fore and middle ones. Femora and middle and hind tibiae with long pigmented stripes. Fore tibiae with characteristic field of numerous brownish strong setae on ventral border, trochanters and femora with numerous translucent long setae on ventral surface, and middle and hind tibiae with numerous brownish strong setae and translucent long setae on ventral surface. Distributions of pigmented patches and chaetotaxy of legs as in Fig. 2 I–K.

Abdominal coxites I–VII with 1+1 eversible vesicles, coxites II–IX with stylets. Coxites I distinctly shorter than coxites II, without urosternite ( Fig. 3A). Coxites II rounded and expanded laterally, with relatively large urosternite with some long hyaline setae on inner subapex; stylets II long and robust, with numerous long hyaline setae ( Fig. 3B). Coxites III–IX glabrous, stylets III–IX with numerous short setae ( Fig. 3 C–E). Ratios of stylets (without terminal spine) to corresponding coxites as follows: 0.73–0.79 for coxites II, 0.50–0.55 for coxites V, 0.51–0.60 for coxites VIII, and 0.67–0.76 for coxites IX. Ratios of terminal spines to corresponding stylets as follows: 0.14–0.25 for coxites II, 0.50–0.52 for coxites V, 0.42–0.53 for coxites VIII, and 0.49–0.55 for coxites IX.

Parameres absent. Penis relatively big, nearly as long as half of coxites IX ( Fig. 3E), aperture reddish, pointed oval ( Fig. 3F).

Description of females. — Body generally larger and longer than males, body length (from apex of head to tip of abdomen) 9.3–10.2 mm; maximum antennae length 24.0 mm; cerci and caudal filament incomplete, not measured ( Fig. 4A ).

Compound eyes with ratios of length to width 0.87–0.90 and line contact to length 0.56–0.60 ( Fig. 4B, C ). Lateral ocelli and frons similar to males. The maximum length of antennae more than twice longer than body length ( Fig. 4A ), scapus nearly 2.5 times as long as its width, with a long dark stripe on inner and outer surfaces ( Fig. 4C, D ).

Maxillary palps similar to males ( Fig. 4E, F ), article II without hook-like process and characteristic strong setae; article V with 2–4 hyaline spines near dorsal apex; articles VI and VII with 22–28 and 32–38 hyaline spines on dorsal surface, respectively; distal article distinctly elongate, with ratio of length of articles VII: VI: V = 1: (0.71–0.78): (0.83–1.05). Distribution of pigmented patches of maxillary palps on inner surface as in Fig. 4E and on outer surface as in Fig. 4F . Labial palps similar to males ( Fig. 4G ).

Legs similar to males, distributions of pigmented patches and chaetotaxy of legs as in Fig. 5 A–C.

Abdominal coxites I–VII similar to males ( Fig. 5 D–F). Ratios of stylets (without terminal spine) to corresponding coxites as follows: 0.74–0.79 for coxites II, 0.49–0.56 for coxites V, 0.57–0.61 for coxites VIII ( Fig. 5G ), and 0.65–0.69 for coxites IX ( Fig. 5I ). Ratios of terminal spines to corresponding stylets as follows: 0.10–0.23 for coxites II, 0.42–0.47 for coxites V, 0.30–0.37 for coxites VIII, and 0.45–0.60 for coxites IX.

Ovipositor tertiary type, slightly extended beyond terminal spines of stylets IX. Gonapophyses VIII with nearly 75 divisions, most them with setae: basal 1/3 divisions with 5–6 short setae, remainders with 4 long setae, apical division with a long setae ( Fig. 5H ). Gonapophyses IX slender, with nearly 65 divisions, basal 2/3 divisions glabrous, the remaining with 1–3 short setae, apical division with a long seta ( Fig. 5J ).

Etymology. — The new species is named after Dr. Dinh-Sac Pham, one of three collectors and an excellent arachnologist from Vietnam.

Biology. — The new species M. (s. str.) phami and M. (Protumidolontus) lii both maybe live in the canopy layer of tropical rainforests in northern Vietnam

Remarks. — The new species is similar to M. (s. str.) yoshii Mendes, 1989 from northern Kalimantan, but can be separated from the latter by its scapus with a long dark stripe on inner and outer surfaces (with a light patch in the basal ventral region and a dark ante-apical ring in yoshii); article II of maxillary palps in males with dorsal hook-like process relatively short and small, incurved internally and ventrally (long and large, pointed dorsally and internally, not incurved, with numerous minute denticulations at apex in yoshii); and the differences of pigmented stripes on legs.

Distribution. — Northern Vietnam (Ninh Binh, Vinh Phuc, Hai Phong).

Figures

Fig. 2. Machilontus (s. str.) phami, new species, male, holotype. A. habitus, lateral view; B. eyes and ocelli, front view; C. same, right lateral-front view; D. distal area of mandible; E. base of antenna; F. maxillary palp, inner view; G. same, outer view; H. labium and labial palp; I. fore leg, outer view; J. middle leg, outer view; K. hind leg, outer view.

Fig. 4. Machilontus (s. str.) phami, new species, female, paratype. A. habitus, lateral view; B. eyes and ocelli, front view; C. same, right lateral-front view; D. base of antenna; E. maxillary palp, inner view; F. same, outer view; G. labium and labial palp.

Fig. 5. Machilontus (s. str.) phami, new species, female, paratype.A. fore leg, outer view; B. middle leg, outer view; C. hind leg, outer view. D. coxites I; E. coxites II; F. coxites V; G. coxites VIII; H. terminal divisions of gonapophyses VIII; I. coxites IX; J. terminal divisions of gonapophyses IX.