Meligethes difficiloides, Audisio & Jelínek & Cooter, 2005

Audisio, Paolo, Jelínek, Josef & Cooter, Jonathan, 2005, New and little-known species of Meligethes Stephens, 1830 from China (Coleoptera: Nitidulidae), Acta Entomologica Musei Nationalis Pragae 45, pp. 111-127 : 14-18

Meligethes difficiloides sp. nov.

( Figs. 1-2, 17 , 20 , 24 )

Type material. HOLOTYPE: J, CHINA: YUNNAN, 10 km SW Lijiang , 5.vii.1994, Schillhammer leg. ( NHMW) . PARATYPES: CHINA: YUNNAN, Weibao Mts. (= Weibaoshan), 25° 12´N, 100° 24´E, 2800-3000 m a.s.l., 29/ 30.vi.1992, V. Kubáň leg., 3 JJ 1 ♀ ( NHMB, CAR). SHAANXI, Qin Ling Mts. (= Oin Ling Shan), road Baoji-Taibai, pass 35 km S of Baoji (= Gochzhen), 21/ 23.vi.1998, O. Šafránek & M. Trýzna leg., 7 JJ 7 ♀♀ ( NMPC, CAR).

Diagnosis. Medium-sized (length 2.5-2.6 mm), blackish-brown with yellowish to orange legs and antennae (antennal club orange-brown), and relatively short golden pubescence. General appearance ( Fig. 24 ) similar to shortened specimens of the Euroasiatic M. difficilis (Heer, 1841) , but with pronotal surface slightly more convex, with slightly deeper and coarser pronotal punctures, and truncate anterior margin of clypeus. Metasternum in male with shallow triangular impression in posterior two thirds, with two moderately raised and wide prominences in the middle, each separated from the other by nearly the same distance separating the mesocoxae. Last ventral sternite in male with a distinct emargination in the middle of posterior margin, which is slightly raised and markedly shining. Front tibiae as in Fig. 20 , similar to those of M. difficilis , but slightly narrower. Male genitalia as in Figs. 1-2 . Ovipositor as in Fig. 17 .

Description. Male holotype. Length 2.50 mm; breadth (at widest point of elytra) 1.38 mm. Scarcely elongate and rather convex ( Fig. 24 ); blackish-brown, with short golden pubescence. Legs yellowish to orange. Antennae yellowish to orange, with slightly darker club.

Head with dorsal punctures slightly larger than eye facets, strongly impressed, separated by less than one diameter, surface between them smooth; front margin of clypeus completely and distinctly bordered, distinctly truncate and with obtusely pointed lateral angles. Frontogeneal furrows distinct and complete. Antennae of normal size for the species group ( Fig. 24 ), third antennomere slender, slightly shorter than second; antennal club medium-sized.

Pronotum 1.85 times as wide as long, broadest at posterior fourth ( Fig. 24 ), narrowed anteriorly; sides narrowly bordered, not explanate; with posterior angles obtuse but distinct. Base slightly sinuate near scutellum; punctures larger, coarser, and deeper than on head, separated by less than one diameter, surface between them smooth and shining.

Scutellum medium-sized, densely punctate throughout; surface between punctures with faint trace of microreticulation. Elytra 1.05 times as long as wide, broadest at basal second fifth, distinctly wider than pronotum (1.18 times); humeri feebly raised, humeral striae indistinct; elytral punctures as on pronotum, surface between them smooth, without microreticulation.

Ventral surface blackish-brown, with fine short pubescence. Prosternal antennal furrows strongly impressed. Prosternal process rather long and sub-parallel, slightly wider than antennal club, with slightly wider and obtusely rounded apex; punctures similar to those on head, surface between them rather shining. Mesosternum with hind margin straight. Metasternum with shallow triangular impression in posterior two thirds, in the middle with two moderately raised and wide prominences separated by nearly the same distance separating the mesocoxae; punctures and the spaces between as on frons, but sparser. Caudal marginal line of hind coxal cavity following closely to posterior edge of cavity and turning back prior to outer end. Last visible abdominal sternite in male with distinct emargination in the middle of posterior margin, which is slightly raised and markedly shining.

Front tibiae ( Fig. 20 ) similar to those of M. difficilis , but narrower, with outer edges finely crenulate from basal third, with a subapical group of 3-5 larger and sharper teeth; front tarsi as wide as antennal club; hind tibiae moderately narrow, with inner edges regularly arcuate, not sinuate ( Fig. 24 ); tarsal claws simple.

Genitalia. Tegmen ( Fig. 1 ) with characteristic calyx-shaped median excision moderately deep and rather wide; aedeagus elongate ( Fig. 2 ), narrowed from distal fifth, with apex broadly pointed.

Female. Metasternum almost simple. Front tarsi narrower, distinctly narrower than antennal club. Ovipositor as in Fig. 17 , with weakly pointed and moderately darkened apex, and long subapical styli.

Variability. Length 2.50-2.60 mm. Teeth on outer edges of front tibiae are slightly variable, but of the pattern described and figured.

Differential diagnosis. This species is probably closely related to M. difficilis , which is widespread from North Africa and western Europe in the west to the eastern Siberia and Japan in the east ( KIREJTSHUK 1992, AUDISIO 1993), but is distinguishable from M. difficilis and from the closely related Anatolian-Caucasian M. dieckmanni Audisio & Jelínek, 1984 ( Figs. 3-4 ) by the shape of male and female genitalia, shorter elytra, deeper pronotal punctures, truncate anterior margin of clypeus, and last ventral sternite in male with shining emargination in the middle of posterior margin.

Etymology. This new species is named difficiloides (= similar to difficilis in Latin) to emphasize its external similarity to M. difficilis .

Bionomy. The biology of this species is not definitively understood, however it is likely associated with Lamiaceae , probably Lamium or related genera, because the closely related M. difficilis and M. dieckmanni and several other species of the M. difficilis -group are known to be associated with these host plants ( AUDISIO 1993). Specimens were collected from late June to July by sweeping in montane mixed forests above 2000 m a.s.l.

Distribution. Known to occur in central and southern China (from Yunnan to central Shaanxi).

Figures

Figs. 1-12. Tegmen and aedeagus (dorsal aspect) of Meligethes Stephens, 1830. 1-2 – M. difficiloides sp. nov., J paratype from Yunnan, Weibao Mts. 3-4 – M. dieckmanni Audisio & Jelínek, 1984, J from Turkey, Kars province, Göle. 5-6 – M. difficilis (Heer, 1841), J from Italy, Rome. 7-8 – M. atrovirens Jelínek, 1982, J from Turkey, Giresun province, Kümbet. 9-10 – M. abditus sp. nov., J paratype from Beijing principality, Xiaolongmen. 11-12 – M. chlorocupreus sp. nov., J paratype from Yunnan, Weibao Mts. Scale bar = 0.20 mm.

Figs. 20-23. Right front tibiae of Meligethes Stephens, 1830. 20 – M. difficiloides sp. nov., J paratype from Yunnan, Weibao Mts.; 21 – M. abditus sp. nov., J holotype from Beijing principality, Xiaolongmen; 22 – M. chlorocupreus sp. nov., J paratype from Yunnan, Weibao Mts.; 23 – M. bocaki sp. nov., J paratype from Yunnan, Luo Shui (23). Scale bar = 0.20 mm.

Figs. 24-27. Body outlines of Meligethes Stephens, 1830. 24 – M. difficiloides sp. nov., J paratype from Yunnan, Weibao Mts.; 25 – M. abditus sp. nov., J holotype from Beijing principality, Xiaolongmen; 26 – M. chlorocupreus sp. nov., J holotype from Yunnan, Weibao Mts.; 27 – M. bocaki sp. nov., J paratype from Yunnan, Luo Shui. Scale bar = 1 mm.