A review of the genus Serangium Blackburn (Coleoptera, Coccinellidae) from China

Abstract The genus Serangium Blackburn from China is reviewed. The genus Catanella Miyatake is removed from synonymy with Serangium. Serangium baculum Xiao is transferred to Catanella, as Catanella baculum (Xiao), comb. n. Twelve species of Serangium are described, keyed and illustrated, including eight new species, Serangium magnipunctatum Wang & Ren, sp. n., Serangium trimaculatum Wang & Ren, sp. n., Serangium centrale Wang & Ren, sp. n., Serangium leigongicus Wang & Ren, sp. n., Serangium latilobum Wang & Ren, sp. n., Serangium digitiforme Wang & Ren, sp. n., Serangium dulongjiang Wang, Ren & Chen, sp. n., and Serangium contortum Wang & Ren, sp. n. Serangium punctum Miyatake is newly recorded from China.


Introduction
The genus Serangium was erected by Blackburn (1889) with S. mysticum Blackburn, 1889, from Australia as the type species. Chapin (1940) pointed out that Serangium and its allied genera form a coherent group, but he did not proposed a tribal name for of Catanella formosana Miyatake, 1961a and found that Catanella's 8-segmented antenna and 3-segmented tarsus are constant, while male and female genitalia are also different from Serangium. Thus, Catanella should be a valid genus. Pang et al. (2004) recorded S. lygacum Iablokoff-Khnzorian, 1972 from China. After our re-examination of this specimen, we conclude that it was an incorrect identification of S. drepnicum Xiao, 1992. In addition, Xiao and Li (1992) described a new species S. baculum with 9-segmented antenna and 4-segmented tarsus. We have examined type materials of S. baculum and found that its antenna has 8-segments and tarsus is 3-segmented which is similar to the characters of the genus Catanella. Therefore we consider that S. baculum is wrongly placed in Serangium and should be moved to Catanella (C. baculum (Xiao) comb. n.) Pronotum and elytra reddish brown, with a dark spot in the middle of elytral suture (Fig. 17). TL: 2.08-2.27mm, TW: 1.88-1.98mm ... S. centrale sp. n. -Pronotum distinctly darker than elytra, elytra burgundy without spot (Fig. 18) Penis has a small pominence at 1/5 length (Fig. 57). Penis guide wide at basal half, sharply narrowed in middle, with a finger-shape apex (Fig. 59). TL: 2.14-2.18mm, TW: Penis distinctly broadening at apical 1/5-2/5 length (Fig. 63). penis guide widest at base, gradually narrowing to middle, with a finger-shape apex (Fig. 65). TL: 2.14-2.21mm, TW: 1.80-1.85mm ........S. digitiforme sp. n. 10
Pronotum short and strongly transverse, 0.58× elytral width (PW/EW=1: 1.72), densely covered in fine punctures associated with long sparse setae, punctures slightly larger than those on head, separated by 1.0-3.0 times their diameter. Punctures on elytra fine and sparse, similar to those on pronotum, with a few long setae at humeral angles and a row of evenly spaced setae along margin. Prosternum shiny, glabrous and impunctate with sparse setae. Mesoventrite small, transverse, surface mat weakly fur-rowed, sparsely setae. Metaventrite shiny, basal half with distinctly median discrimen; punctures around median discrimen very large and dense, with short thick setae, and on other parts fine and sparse, separated by 2.0-6.0 times their diameter, with short sparse setae.
Male genitalia. Penis strongly curved in whole length, apex shortly narrowing and rounded, penis capsule indistinct (Fig. 26). Tegmen rather slender and strongly asymmetrical . Penis guide in ventral view flattened and elongate tongue-shape. Left paramere in ventral view flat and short bearing a few long setae, and right piece short but distinctly projecting, bearing a few long setae (Fig. 28). Penis guide in lateral view long and thin, almost straight, apex pointed. Right paramere in lateral view about 1/2 of penis guide (Fig. 27).
Female genitalia. Genital plate elongate triangular with a rounded apex, sparsely hairy on the apical portion, stylus rather long, bearing few setae (Fig. 29). Spermatheca divided into two parts, one of which is somewhat globular with a feeble constriction and two small pinch-like projections, the other is tubular, becoming slightly more slender distally (Fig. 29).
Pronotum short and strongly transverse, 0.68× elytral width (PW/EW=1: 1.46), sparsely covered in moderated large punctures associated with long sparse setae, punctures similar to those on head, separated by 2.0-6.0 times their diameter. Punctures on elytra very fine and sparse, smaller than those on pronotum, separated by 3.0-8.0 times their diameter, with a row of evenly spaced setae along margin. Prosternum shiny and glabrous, with sparse punctures and setae. Mesoventrite small, transverse, surface mat, weakly furrowed. Metaventrite shiny, basal half with distinctly median discrimen; punctures around median discrimen very large and dense, with short thick setae, and on other parts moderated large, sparse, separated by 2.0-5.0 times their diameter, with short sparse setae.
Male genitalia. Penis stout, strongly curved in whole length, apex narrowing and rounded, penis capsule indistinctly (Fig. 31). Tegmen slender and strongly asymmetrical . Penis guide in ventral view flattened and tongue-shape, slightly wider and shorter than S. japonicum (Fig. 33). Left paramere in ventral view flat and short bearing a few long setae, and right piece short but distinctly projecting, bearing a few long setae. Penis guide in lateral view thin and straight, apex pointed. Right paramere in lateral view stout, about 2/3 of penis guide (Fig. 32).
Female genitalia. Genital plate elongate triangular with a rounded apex, sparsely hairy on the apical portion, stylus rather long, bearing few setae (Fig. 35). Spermatheca divided into two parts, one of which is somewhat globular with a feeble constriction and two small pinch-like projections, the other is tubular, becoming slightly more slender distally (Fig. 34 Diagnosis. This species is similar to S. clauseni in general appearance and male genitalia, from which it differs in its dorsal color pattern, elytra with a few large inner punctures at basal margins and along elytral suture (Fig. 15). The male genitalia are also diagnostic: penis is slightly thinner than S. clauseni (Figs  Body minute, hemispherical, dorsum strongly convex, glabrous (Fig. 15). Head yellow, pronotum reddish brown to black, except light-colored anterior angles and basal margin. Scutellum reddish brown to black. Elytra red to black, sometimes elytra black with median part red. Underside reddish brown and legs yellow.
Pronotum short and strongly transverse, 0.72× elytral width (PW/EW=1: 1.39), sparsely covered in fine punctures associated with long sparse setae, punctures smaller than those on head, separated by 2.0-4.0 times their diameter. Elytra with a few large inner punctures at basal margins and two rows of large punctures along elytral suture. Pro-and mesoventrites mat and weakly furrowed, with short sparse setae. Metaventrite shiny and glabrous, basal half with distinctly median discrimen; punctures around median discrimen large and dense, with short thick setae.
Male genitalia. Penis strongly curved in whole length, apex shortly narrowing and rounded, penis capsule indistinctly (Fig. 37). Tegmen rather slender and strongly asymmetrical . Penis guide in ventral view flattened and tongue-shape (Fig. 39). Left paramere in ventral view very short bearing a few long setae, and right piece short and stout, distinctly projecting, bearing a few long setae (Fig. 39). Penis guide in lateral view thin and straight, apex pointed. Right paramere in lateral view short, about 1/3 of penis guide (Fig. 38).
Female genitalia. Genital plate elongate triangular with a rounded apex, sparsely hairy on the apical portion, stylus long, bearing few setae (Fig. 41). Spermatheca divided into two parts, one of which is somewhat globular with a feeble constriction and two small pinch-like projections, the other is tubular, becoming slightly more slender distally (Fig. 40 Diagnosis. This is a very distinctive species having three black spots on the elytra (Fig. 16). The male genitalia are similar to S. punctum, but can be distinguished from latter by long left paramere and apex of penis guide (Figs 44-45 Body minute, hemispherical, dorsum strongly convex, shiny and glabrous (Fig. 16). Head orange, pronotum and scutellum orange. Elytra orange, with three black spots: two on the center of elytra and one on the middle of suture. Underside yellowish brown, except pro-, meso-and metaventrites black. Legs yellowish brown.
Pronotum short and strongly transverse, 0.70× elytral width (PW/EW=1: 1.43), sparsely covered in fine punctures associated with long sparse setae, punctures smaller than those on head, separated by 1.5-4.0 times their diameter. Punctures on elytra very fine and sparse, similar to those on pronotum, with a row of evenly spaced setae along margin. Prosternum glabrous, punctures fine and sparse, separated by 2.0-3.0 times their diameter, with a few short setae. Mesoventrite small, transverse, surface shiny and impunctate. Metaventrite shiny, basal half with distinctly median discrimen; punctures inconspicuous, with short sparse setae.
Male genitalia. Penis long and slender, strongly curved in whole length, apical half of siphon strongly narrowing apical, and apex very thin and sharply pointed, penis capsule broadening basally and with a distinct inner process (Fig. 43). Tegmen strongly asymmetrical and extremely complicate . Penis guide moderatedly elongate, with a finger-like apex, a small prominence at right side near the apex, bearing many distinct hairs dorsally (Fig. 45). Right lateral lobe of tegmen short, bearing dense setae. Left lateral lobe of tegmen relatively long, rounded apical without any setae (Fig. 45) Diagnosis. This species is similar to S. magnipunctatum in general appearance, but it is easily distinguished from the latter by sharply pointed penis apex and extremely com-plex tegmen (47)(48)(49). The male genitalia are similar to S. trimaculatum, but can be distinguished from latter by the shorter left paramere and the apex of penis guide (48)(49).
Body minute, hemispherical, dorsum strongly convex, shiny and glabrous (Fig. 17). Head yellowish brown, pronotum reddish brown, scutellum dark brown. Elytra reddish brown, with a castaneous area in the middle of suture. Underside yellowish brown, legs yellowish brown.
Pronotum short and strongly transverse, 0.70× elytral width (PW/EW=1: 1.43), densely covered in moderated large punctures associated with long dense setae, punctures slightly smaller than those on head, separated by 0.5-1.5 times their diameter. Punctures on elytra fine and sparse, smaller than those on pronotum, separated by 2.0-4.0 times their diameter, with a few large inside punctures at basal margins and two row of large inner punctures along elytral suture. Prosternum mat, with long dense setae. Mesoventrite small, transverse, surface mat weakly furrowed and impunctate. Metaventrite shiny and glabrous, basal half with inconspicuous median discrimen; punctures fine and sparse, separated by 2.0-4.0 times their diameter.
Male genitalia. Penis long and slender, strongly curved in whole length, apical half of siphon strongly narrowing apical, and apex very thin and sharply pointed, penis capsule broadening basally and without distinct inner and outer processes (Fig. 47). Tegmen strongly asymmetrical and extremely complicate . Penis guide relatively short with a distinctly pointed apex, a small gap at right side and a prominence at left side near the apex, bearing a tuft of setae (Fig. 49). Right lateral lobe of tegmen relatively short and wide, bearing a tuft of setae. Left lateral lobe of tegmen slightly longer and narrower than right, without any hairs (Fig. 49). Basal piece of tegmen with a long process.
Female genitalia. Genital plate elongate triangular, apical part of the plate narrow and parallel-sided with a rouned apex, stylus of the genital plate very elongate with a few long setae at its apex (Fig. 51). Spermatheca divided into two globular parts, each with a small pinch-like projection (Fig. 50) Diagnosis. This species is similar to S. centrale in male genitalia, but it is easily distinguished from the latter by minute body size, slender penis, shorter penis capsule, apex of penis guide with a triangular process at left side (Figs 47-49, 53-55).
Body minute, hemispherical, dorsum strongly convex, shiny and glabrous (Fig. 18). Head brown, except frons yellowish brown. Pronotum and scutellum dark brown. Elytra burgundy, with a dark area in the middle of suture. Underside dark red. Legs yellowish brown.
Pronotum short and strongly transverse, 0.76× elytral width (PW/EW=1: 1.32), sparsely covered in fine punctures associated with moderately dense setae, punctures smaller than as those on head, separated by 1.0-3.0 times their diameter. Punctures on elytra fine, similar as those on pronotum, separated by 2.0-4.0 times their diameter, with a row of evenly spaced setae along margin. Prosternum mat, shagreened and impunctate. Mesoventrite glabrous. Metaventrite shiny and glabrous, without median discrimen; punctures fine and sparse, separated by 2.0-5.0 times their diameter, slightly larger and denser in center.
Male genitalia. Penis long and slender, strongly curved in whole length, apical half of siphon strongly narrowing apical, and apex very thin and sharply pointed, penis capsule broadening basally and with distinct inner and outer processes (Fig. 53). Tegmen strongly asymmetrical and extremely complicate (Figs 54-55). Penis guide relatively short with a distinctly pointed apex, a small triangular process at left side and a prominence at left side near the apex, bearing dense setae dorsally and ventrally (Fig. 55). Right lateral lobe of tegmen short, bearing spaesrly setae. Left lateral lobe of tegmen slightly longer than right, without any setae (Fig. 55) Diagnosis. This species is similar to S. japonicum in general appearance, but it can be distinguished from the latter by lager body size, uniform black pronotum without other color and elytra with very conspicuous swelling (Fig. 19). The male genitalia are also diagnostic: penis is moderated stout (Fig. 57), right paramere is indistinct (Fig. 58), penis guide is wide at basal half, sharply narrowed at middle with a finger-shape apex (Fig. 59).
Pronotum short and strongly transverse, 0.70× elytral width (PW/EW=1: 1.43), covered in fine punctures associated with long dense setae, punctures similar as those on head, separated by 1.0-2.0 times their diameter. Punctures on elytra fine and sparse, similar to those on pronotum, separated by 2.0-3.0 times their diameter, with a few long setae at humeral angles and a row of evenly spaced setae along margin. Prosternum mat, with sparse setae. Mesoventrite glabrous and impunctate, with sparse setae. Metaventrite shiny and glabrous, basal half with distinctly median discrimen; punctures around median discrimen large and dense, with short thick setae, punctures on the rest parts indistinct, with sparse setae.
Male genitalia. Penis strongly curved in whole length, with a small prominence at 1/5, apex slightly curved, penis capsule broadening basally and with indistinct inner and outer processes (Fig. 57). Tegmen rather slender and strongly asymmetrical (Figs 58-59). Penis guide in ventral view wide at basal half, sharply narrowed at middle, then contort, forming a distinct gap in middle, apical half elongate finger-shape. Left paramere in ventral view indistinct, bearing a few long setae, and right piece very short, bearing a few long setae (Fig. 59). Penis guide in lateral view widest at base, gradually tapering to apex, basal 1/5 with a small angular prominence, apex sharply pointed (Fig. 58).
Head transverse and ventrally flattened, 0.39× elytral width (HW/EW=1: 2.60); punctures on frons fine, separated by 1.0-3.0 times their diameter, with sparse setae; eyes moderately large and coarsely faceted, widest interocular distance 0.52× head width. Antenna 9-segmented, terminal segment large, elongate oval and flat, apex angular. Pronotum short and strongly transverse, 0.70× elytral width (PW/EW=1: 1.43), covered in fine and dense punctures associated with moderately dense setae, similar to those on head, separated by 0.5-1.5 times their diameter. Punctures on elytra fine and sparse, slightly smaller than those on pronotum, separated by 2.0-3.0 times their diameter, with a few long setae at humeral angles and a row of evenly spaced setae along margin. Prosternum mat and shagreened, with sparse setae. Mesoventrite glabrous and impunctate, with sparse setae. Metaventrite shiny and glabrous, basal half with distinctly median discrimen; punctures around median discrimen very large and dense, with short thick setae, punctures on the rest parts moderated and sparse, separated by 2.0-4.0 times their diameter, with sparse setae. Male genitalia. Penis strongly curved in whole length, distinct distinctly broadening at 1/5-2/5, apex narrowing and slightly curved, penis capsule broadening basally and with indistinct inner and outer processes (Fig. 63). Tegmen rather slender and strongly asymmetrical (Figs 64-65). Penis guide in ventral view widest at base, strongly narrowing to middle, then contorted, apical half finger-shape. Left and right paramere in ventral view short, bearing a few long setae (Fig. 65). Penis guide in lateral view widest at base, gradually tapering to apex (Fig. 64).
Female genitalia. Genital plate triangular with a rounded apex, slightly concaved in middle, sparsely hairy on the apical portion, stylus rather long, bearing few setae (Fig. 66). Spermatheca divided into two parts, one of which is somewhat globular with a constriction and two small pinch-like projections, the other is short tubular, becoming slightly more slender distally (Fig. 65).
Pronotum short and strongly transverse, 0.70× elytral width (PW/EW=1: 1.43), covered in fine punctures associated with long sparse setae, separated by 1.0-3.0 times their diameter. Punctures on elytra fine and sparse, smaller than those on pronotum, separated by 2.0-4.0 times their diameter, with a row of evenly spaced setae along margin. Prosternum mat, with sparse setae. Mesoventrite glabrous and impunctate, with sparse setae. Metaventrite shiny and glabrous, basal half with distinctly median discrimen; punctures fine and sparse, separated by 2.0-5.0 times their diameter, with short sparse setae.
Male genitalia. Penis strongly curved in whole length, apex shortly narrowing and rounded, penis capsule indistinct (Fig. 69). Tegmen rather slender and strongly asymmetrical (Figs 70-71). Penis guide in ventral view flattened and elongate tongue-shape. Left paramere in ventral view indistinct bearing a few long setae, and right piece distinctly projecting, bearing a few long setae (Fig. 71). Penis guide in lateral view long and thin, straight, apex sharply pointed (Fig. 70).
Female genitalia. Genital plate elongate triangular with a rounded apex, sparsely hairy on the apical portion, stylus long, bearing few setae (Fig. 73). Spermatheca divided into two parts, one of which is somewhat globular with a feeble constriction and two small pinch-like projections, the other is long tubular, becoming slightly more slender distally (Fig. 72).
Pronotum short and strongly transverse, 0.71× elytral width (PW/EW=1: 1.40), evenly covered in moderately large punctures associated with long sparse setae, punctures slightly smaller than those on head, separated by 1.5-3.0 times their diameter. Punctures on elytra fine, slightly smaller than those on pronotum, separated by 2.0-4.0 times their diameter, with a few long setae at humeral angles and a row of evenly spaced setae along margin. Prosternum mat and shagreened. Meso-and metaventrites without distinctly median discrimen; punctures large and sparse, separated by 1.5-3.0 times their diameter, with sparse setae.
Male genitalia. Penis long and slender, strongly curved in whole length, apical half of siphon strongly narrowing apical, and apex very thin and sharply pointed, penis capsule broadening basally and without distinct inner and outer processes (Fig. 75). Tegmen strongly asymmetrical and extremely complicate . Penis guide moderatedly elongate, with a pointed apex, a small triangular process at left side near the apex and an angulate prominence at middle of left side, bearing sparse setae (Fig. 77). Right paramere relatively long, 1/2 of penis guide length, bearing minute setae. Left lateral lobe of tegmen slightly longer than right, flat and elongate oval without any hairs (Fig. 77). Paramere in lateral view arcuate, with a sharply pointed apex (Fig. 76). Basal piece of tegmen with a long process.
Female genitalia. Genital plate elongate triangular, apical part of the plate narrow and parallel-sided with a rouned apex, stylus of the genital plate very elongate with a few long setae at its apex (Fig. 79). Spermatheca divided into two parts, one of which is globular with a small pinch-like projection, the other nearly hemispherical, with a small pinch-like projection (Fig. 78 Diagnosis. This species is close to S. digitiforme in general appearance and male genitalia, but it is distinguished from the latter as follow: penis is long and slender (Fig. 81), penis guide is elongated tongue-shaped (Fig. 83), and the first part of spermatheca has a strong constriction in middle (Fig. 84). In S. digitiforme, penis is moderately long and stout, distinctly broadening at apical 1/5-2/5 (Fig. 63), penis guide is finger-shaped (Fig. 65), and the first part of spermatheca has a feebly constriction in middle (Fig. 66) Body minute, hemispherical, dorsum strongly convex, shiny and glabrous (Fig. 23). Dorsum uniformly black. Head orange to dark brown. Underside black. Legs yellowish brown to dark red, except tarsi yellow.
Pronotum short and strongly transverse, 0.71× elytral width (PW/EW=1: 1.42), densely covered in fine punctures associated with long dense setae, punctures similar to those on head, separated by 0.5-1.0 times their diameter. Punctures on elytra fine and sparse, similar to those on pronotum, separated by 2.0-3.0 times their diameter, with a row of evenly spaced setae along margin. Prosternum mat, with sparse setae. Mesoventrite glabrous and impunctate. Metaventrite shiny and glabrous, without distinctly median discrimen; punctures in center large and dense, with short thick setae.
Male genitalia. Penis very long and slender, strongly curved in whole length, apex shortly narrowing and rounded, penis capsule indistinct (Fig. 81). Tegmen rather slender and strongly asymmetrical (Figs 82-83). Penis guide in ventral view widest at base, gradually narrowing to middle, then strongly narrowed and contorted, apical elongate tongue-shape. Left paramere in ventral view short bearing a few long setae, and right piece short but distinctly projecting, bearing a few long setae (Fig. 83). Penis guide in lateral view long and thin, almost straight, with a angular prominence near the base, apex pointed (Fig. 82).
Female genitalia. Genital plate elongate triangular with a rounded apex, slightly concaved in middle of outer margin, apical portion with sparsely setae, stylus long, bearing few setae (Fig. 85). Spermatheca divided into two parts, one of which is somewhat globular with a strong constriction and two pinch-like projections, the other is tubular, becoming slightly more slender distally (Fig. 84) Diagnosis. This species is easily recognized by its metaventrite without median discrimen and the contorted penis guide (Figs 88-89).
Pronotum short and strongly transverse, 0.72× elytral width (PW/EW=1: 1.39), covered in fine inconspicuous punctures associated with long dense setae, punctures slightly smaller than those on head, separated by 1.0-1.5 times their diameter. Punctures on elytra fine and sparse, smaller than those on pronotum, separated by 2.0-3.0 times their diameter, with a row of evenly spaced setae along margin. Prosternum mat, punctures fine and inconspicuous, with sparse setae. Mesoventrite glabrous. Metaventrite shiny and glabrous, without distinctly b median discrimen; 5-6 large and dense punctures forming two cluster in the center, with short thick setae, punctures on the rest parts indistinct, with sparse setae.
Male genitalia. Penis long and stout, strongly curved in whole length, apex strongly narrowing and rounded, penis capsule indistinct (Fig. 87). Tegmen rather slender and strongly asymmetrical (Figs 88-89). Penis guide in ventral view strongly contorted in middle. Left paramere in ventral view short bearing a few long setae, and right piece short but distinctly projecting, bearing a few long setae (Fig. 89). Penis guide in lateral view wide in basal half, then sharply narrowed, apical half very thin, apex pointed (Fig. 88).
Female genitalia. Genital plate elongate triangular with a rounded apex, distinctly concaved in middle of outer margin, apical portion with sparsely setae, stylus long, bearing few setae (Fig. 91). Spermatheca divided into two parts, one of which is somewhat globular with a feeble constriction and two pinch-like projections, the other is tubular, becoming slightly more slender distally (Fig. 90).
Distribution. China (Guangxi, Hubei, Yunnan). Etymology. The specific epithet formed from the Latin adjective contortus, referring to contorted penis guide of tegmen.