Mesosaimia similis ( Breuning, 1950 ) Breuning, 1950

Yamasako, Junsuke, 2014, Review of the genus Mesosaimia Breuning with description of a new species (Coleoptera: Cerambycidae: Lamiinae: Mesosini), Zootaxa 3852 (4), pp. 461-474 : 466-467

Mesosaimia similis ( Breuning, 1950) comb. nov.

( Figs 5–9 , 18–19 , 30–36 , Pl. 1)

Trichomesosa similis Breuning, 1950: 520 ,

type locality: Vietnam, Lang Son Prov, Mt. Mauson.

Type material examined. Holotype ( MHNL, Fig. 9 ): ♂, “ Tonkin / Montes Mauson / April, Mai 2 -3000’ / H. Fruhstorfer ”, “ Trichomesosa / similis / mihi Typ / S. Breuning det., 1942 ”, “ Trichomesosa / similis / Br. / P. Lepesme det.”, “TYPE”, “Coll. Lepesme / 2002 / Muséum de Lyon / 47016046 ” .

Other material examined. 1♂ ( MHNL, Figs 5–6 , 18 ), Mt. Mauson, Vietnam, IV–V, H. Fruhstorfer ; 1♂, Mt. Tamdao, Vinh Phuc Prov., Vietnam, VI–VII, 1992, Native Coll.; 1♀ ( Fig. 7–8 , 19 ), same locality, 27–29. V, 1996, T. Kurihara Coll .; 1♂, same locality, 10. VI, 1996, M. Ito leg. ; 1♀ ( NSMT), same locality, V, 1999, Native Coll .; 1♂ ( Figs 30–36 ), same locality, VI, 2006, J. Yamasako Coll .

Differential diagnosis. This species is similar to M. robusta , but distinguishable by the following features: body dominantly covered with whitish ocher pubescence in male, and orange ocher pubescence in female instead of brown pubescence; basal swellings of elytra weak; APH of endophallus rudimentary.

Redescription. Male (n = 4, Figs 5–6 , 9 , 18 ): Length from vertex to elytral apices 18.0–22.0 mm, width across humeri 6.8–9.0 mm.

Body black, covered with whitish ocher pubescence except antennae and tarsi; head, antennal scape, pronotum, elytra and femora sparsely scattered with small black spots. Head with pair of longitudinal narrow black bands on occiput behind upper eye lobes. Antennae with scape annulate with whitish ocher pubescence on middle; pedicel with same pubescence; antennomeres 3–11 annulate with whitish ocher or white pubescence on each basal half and the remainders with black pubescence. Pronotum with pair of longitudinal interrupted black bands on disk, a transversal indistinct band on each lateral side. Elytra with several large black patches transversely arranged on basal 1/3 and behind middle. Legs with femora annulate with whitish ocher pubescence except each apex; tibiae with same pubescence on middle and annulate with black pubescence on each base and apex; tarsi with tarsomeres 1–2 covered with same pubescence; tarsomere 3 with black pubescence; claw clothed with whitish ocher pubescence on basal 2/3.

Head with frons having sparse fine punctures; upper and lower eye lobes connected by 2–3 rows of ommatidia; lower eye lobe 1.1–1.2 times as long as width, 0.7–0.8 times as long as gena. Antennae 1.8 times as long as body, surpassing elytral apices near apex of antennomere 5, sparsely fringed beneath by suberect setae that become sparser toward apical segments; relative length of each segment as follows: 1.1: 0.2: 1.8: 1.2–1.3: 0.9–1.0: 0.8–0.9: 0.8: 0.7–0.8: 0.7: 0.7: 0.7. Pronotum widest near middle, 0.7–0.8 times as long as width, 0.7 times as wide as elytral base; disk provided with pair of distinct obtuse swellings, with sparse fine punctures shallow and indistinct in apical half, distinct and umbilicate in basal half. Elytra 0.6–0.7 times as long as body length, 1.6–1.7 times as long as humeral width, with several granules in basal 1/5, weakly swollen longitudinally near middle behind base, with sparse punctures distinct in basal half, reduced apically and almost disappearing in apical part; sides slightly and straightly narrowed toward apical 1/4, arcuately narrowed apically; apex rounded with subquadrate inner angle.

Male genitalia (n = 2, Figs 30–36 ): Tegmen with lateral lobe about 1/4 times as long as the total length of tegmen, slightly narrowed toward apical half, slightly dilated toward rounded apex, with setae that arise from apical half of latero-ventral side, denser and longer apically, concentrated near apex, with minute setae on basal part of ventral side. Median lobe with apex roundly acuminated in ventral view; median struts dehiscent from just behind middle. Endophallus almost triple length as median lobe; BPH almost half length of median lobe; MT+CT about twice as long as median lobe; PB about half length of median lobe. MT+CT curved dorsally in basal 1/6; PB swollen in bullet shape together with APH; APH rudimentary. MSp densely distributed in apical half of MT+CT; LSp evenly and densely arranged in basal half of MT+CT except for basal part; SSp evenly and densely covered almost area of PB.

Female (n = 2, Figs 7–8 , 19 ): Length from vertex to elytral apices 20.6–22.0 mm, width across humeri 8.2–9.0 mm.

Similar to male, but body more rotund, covered with orange ocher pubescence. Head with lower eye lobe 1.2 times as long as width, 0.7–0.8 times as long as gena. Antennae 1.0 times as long as body length; scape to antennomere 5 sparsely fringed beneath by suberect setae; antennomere 11 short and conical shaped; relative length of each segment as follows: 1.8–2.0: 0.3: 2.5–2.7: 1.4–1.5: 0.8–0.9: 0.6–0.7: 0.6: 0.5: 0.4–0.5: 0.4–0.5: 0.4–0.5.

Distribution (Pl. 1). Vietnam (Lang Son Prov. and Vinh Phuc Prov.)

This is first record of this species from Tam Dao, Vinh Phuc Prov.

Taxonomical notes. This species was described on the basis of a single male specimen from “Monts Mauson, Tonkin ” under Trichomesosa as the second species of the genus ( Breuning 1950). It is however distinctly different from T. bifasciata (Pic, 1925) which is the type species of Trichomesosa in the following characteristics: body robust; eye nearly subdivided; antennae subequal to body length in female; antennal scape thick; mesosternal process ridged, with pair of small tubercles near apex; endophallus with APH rudimentary. In contrast, this species shares not only external features but also endophallic structures with Mesosaimia robusta . It is therefore transferred to Mesosaimia .

Figures

FIGURES 1 – 8. Habitus of Mesosaimia spp. 1 – 2. Mesosaimia robusta (male, lectotype); 3 – 4. ditto (female, paralectotype); 5 – 6. M. similis (male); 7 – 8. ditto (female); 1, 3, 5, 7. dorsal view; 2, 4, 6, 8. lateral view.

FIGURES 9 – 15. Habitus of Mesosaimia spp. 9. Mesosaimia similis (male, holotype); 10 – 11. M. mausoni (female, holotype); 12 – 13. M. wakaharai (male, holotype); 14 – 15. ditto (female, paratype); 9, 10, 12, 14. dorsal view; 11, 13, 15. lateral view.

FIGURES 16 – 22. Frontal views of Mesosaimia spp. 16 – 17. Mesosaimia robusta; 18 – 19. M. similis; 20. M. mausoni; 21 – 22. M. wakaharai; 16, 18, 21. male; 17, 19, 20, 22. female; 16. lectotype, 17. paralectotype, 20, 21. holotype; 22. paratype.

FIGURES 30 – 36. Male genitalia of Mesosaimia similis. 30. Tegmen in dorsal view; 31. ditto in lateral view; 32. lateral lobes in ventral view; 33. median lobe with CS in dorsal view; 34. ditto in lateral view; 35. apex of median lobe in ventral view; 36. median lobe with fully inflated endophallus without eversion in lateral view. Scale = 1.0 mm. See text for abbreviations.