Munina Chen, 1976

K, Jan Bezd Ě, 2009, Revision of the genus Munina (Coleoptera: Chrysomelidae: Galerucinae), with the description of M. laotica sp. nov. from Laos, Zootaxa 2032, pp. 55-62 : 56-57

Genus Munina Chen, 1976

Munina Chen in Chen et al., 1976: 210, 221; Seeno & Wilcox, 1982: 113.

Type species: Munina donacioides Chen, 1976 (by original designation and monotypy).

Redescription. Body elongate, dorsum metallic blue, distinctly opalescent, head and pronotum sometimes reddish, legs and antennae black.

Head small, measured with eyes slightly narrower or as wide as anterior margin of pronotum, eyes large, distinctly projecting beyond the outline of the head. Labrum transverse, with anterior margin shallowly incised, covered with several long setae laterally. Clypeus with obtuse keel posteriorly reaching the interantennal space. Genae very short, 0.3 times as long as the diameter of the eye. Frontal tubercles convex, distinctly elevated, subtriangular, apices elongate, separated from vertex and also from each other by deep sulci. Frons with shallow depression behind frontal tubercles. Vertex flatened, covered with fine, almost indistinct punctures. Antennae slender, slightly shorter to slightly longer than the body, male with segments 2 and 3 very short, antennomere 4 3–4 times as long as two preceding ones together; female with segment 3 twice longer than the second one.

Pronotum subquadrate, slightly wider than longer, much narrower than the base of elytra. Lateral and posterior margins distinctly bordered, anterior margin with very thin, but distinct border. Surface of pronotum distinctly concave, lustrous, with more or less distinct shallow depressions laterally, covered with very fine, indistinct punctures. Anterior angles prominent, bulged; posterior angles prominent, triangular, situated at lateral sides, posterior margin just behind posterior angles oblique. All angles with setigerous pore bearing long pale seta.

Scutellum subtriangular, with rounded tip, subopaque to lustrous, covered with microsculpture or indistinct fine punctures.

Elytra with well developed humeral calli. Surface densely covered with large punctures arranged in irregular striae and with long pale hairs. Interspaces between punctures slightly swelling. Postscutellar area with shallow depression. Epipleurae well developed, initially wide, tapered at one quarter of elytral length and then gradually narrowed posteriad, dissapearing before apex. Macropterous.

Legs long, narrow, middle and posterior tibiae unarmed at apex. First segment of posterior tarsi 1.5 times longer than the following two segments together.

Anterior coxal cavities closed behind, prosternum well visible between coxae.

Aedeagus long and thin, with slightly extended and flatened apical part ( Figs. 5–6 ). Spermatheca with hook–like cornu, nodulus bulbous, collum tubular, constricted, ductus receptaculi very long, not coiled. Tignum thin, very long, with apex slightly extended.

Sexual dimorphism. Males can be easily separated from females by the length of the second and third antennomeres, which are very short and equal in length in males, while the third antenomere is twice to three times longer than the second one in females. Last male ventrite with two small short incisions (ventrite entire in females). Although the number of specimens examined is low, the colour difference seems to be distinct – females have opalescent reddish pronotum, while males are almost completely opalescent blue.

Discussion. The insufficient description of genus Munina has not allowed the correct generic placement within Galerucinae . Based on the long basimetatarsus it was compared only with the genera Monolepta Chevrolat, 1837 , and Pseudosepharia Laboissière, 1936 , in the original description ( Chen, 1976). Seeno & Wilcox (1982) adopted this information and included Munina in the section Monoleptites, within the tribe Luperini Leng, 1920.

The examination of Munina specimens enables me to resolve its tribal placement. The combination of several characters (widely closed prothoracic coxal cavities, unarmed middle and posterior tibiae, structure of both male and female genitalia, last ventrite in male with only shallow incisions, antennomeres 2 and 3 very short and equal in length in males while antennomere 3 much longer than second one in females) clearly shows the generic position out of Monoleptites. According to the galerucine system proposed by Seeno & Wilcox (1982), the same characters indicates the close relationship with genera Proegmena Weise, 1889 , Dercetina Gressitt & Kimoto, 1963 , Dercetisoma Maulik, 1936 , and Arthrotus Motschulsky, 1857 , within the section Antiphites Chapuis, 1875 (tribe Sermylini Wilcox, 1965).

The genus Munina can be distinguished from the habitually similar genera Proegmena , Dercetina , Dercetisoma and Arthrotus by elytral surface densely covered with large punctures arranged in irregular striae and with long pale hairs (species of other genera has elytra glabrous and covered with fine confused punctures).

Distribution. China (Yunnan), Laos.

Figures

FIGURES 5 – 10. Details of males of Munina. 5 – 6: aedeagus (dorsal view at left, lateral view at right); 7 – 8: pronotum; 9 – 10: last ventrite. 5, 7, 9 — M. donacioides; 6, 8, 10 — M. laotica sp. nov. Scale bar 1 mm.