Dercetina chinensis (Weise, 1889)

Lee, Chi-Feng & Bezdek, Jan, 2013, Revision of the genus Dercetina from Taiwan and their similar species, with description of a new species from Myanmar (Insecta, Chrysomelidae, Galerucinae), ZooKeys 323, pp. 1-33 : 7-9

Dercetina chinensis (Weise, 1889) stat. r.

Arthrotus chinensis Weise, 1889: 626; Ogloblin 1936: 330 (Jiangsu); Kimoto 1989b: 229 (as synonym of Dercetina flavocincta Hope, 1831)

Dercetina chinensis : Gressitt and Kimoto 1965: 802.

Antipha varipennis Jacoby, 1890: 214. synonymy confirmed

Dercetina varipennis : Gressitt and Kimoto 1963: 710 (as synonym of senior Dercetina chinensis ); Kimoto 1965: 489; Gressitt and Kimoto 1965: 802 (corrected as junior synonym of Dercetina chinensis ).

Type series.

Arthrotus chinensis : Holotype ♀ (MNHUB): "Yunnan Fischer / Yünnan Fischer / Arthrotus chinensis 89., m. / Typus (red label) / Arthrotus chinensis Wse L. N. Medvedev det. 1987". Although locality labels of the holotype didn’t fit the original description, where Peking is clearly indicated, we prefer to treat it as true holotype because the specimen perfectly fit the original description and bears also original Weise´s handwritten identification label.

Antipha varipennis : Lecotype ♂ (BMNH), here designated, labeled: "Chang Yang A. E. Pratt Coll. July 1888. / Jacoby Coll. 1909-28a / varipennis Jac". Paralectotypes: 1♂ (BMNH), same with lecotype but without determination label; 2♂♂ with black elytra and same labels are not designated as paralectotypes since Jacoby (1890) himself explicitely excluded dark specimens from the type series. Three more paralectotypes are deposited at the MCZC: 2♂♂, labeled "Chang Yang A. E. Pratt Coll. July 1888. / 1st Jacoby Coll."; 1♂, same but with additional labels: "Type 18269 (red label) / Antipha varipennis Jac. / Jan.-Jul. 2004 MCZ Image Database".

Diagnosis.

Dercetina chinensis is similar to Dercetina taiwana by the absence of lateral fovea on the pronotum and by the antennomere IV being slightly longer than III. It can be distinguished by its characteristic color patterns (yellowish brown elytra with black longitudinal bands along suture and lateral margins) and oblong elytra (1.6 times longer than wide in contrast to 1.4 times longer than wide in Dercetina taiwana ).

Redescription.

Color very variable, in pale individuals generally yellowish brown, antennae, apical 2/3 of tibiae, and tarsi dark brown, meso- and metathoracic and abdominal ventrites blackish brown, margin of scutellum, and suture and lateral margins of elytra darkened (Fig. 23); in darker individuals black areas on elytra expanding inside, scutellum blackish brown, and head sometimes darkened (Fig. 24); in some individuals entire elytra black (Fig. 25); in darkest individuals entire body black (Fig. 26). Head smooth and impunctate. Pronotum transverse, 1.8 times wider than long, evenly convex on disc and lacking fovea or punctured depression, disc with scattered fine punctures; lateral margin rounded, anterior margin slightly concave, posterior margin slightly rounded. Elytra parallel-sided, apex convergently rounded, 1.6 times longer than wide, disc with random punctures, epipleurae smooth and impunctate.

Male. Length 4.7-5.2 mm, width 2.4-2.8 mm. Atennomere II as long as antennomere III, ratio of length of antennomeres III to VIII ( IX–XI lost) about 1.0: 1.3: 1.3: 1.3: 1.5: 1.5; ratio of length to width of antennomeres III to VIII about 2.3: 2.7: 2.9: 3.3: 3.5 (Fig. 29). Penis (Fig. 31) extremely slender, about 10.6 times longer than wide, parallel-sided, basally and apically widened; apex narrowly rounded, with small process in middle; tectum membranous, with dense stout setae; moderately curved in lateral view (Fig. 32); endophallic sclerites elongate, about 0.5 times as long as penis, apex concave and membranous, with a dorsal sclerite connected at middle, almost reaching base, with a row of short setae along lateral margin at apical 1/3; in lateral view almost straight.

Female. Length 4.5 mm, width 2.5 mm. Antenna comparatively narrower than male (Fig. 30), ratio of length of antennomeres III to XI about 1.0: 1.3: 1.3: 1.3: 1.3: 1.3: 1.3: 1.3: 1.6; ratio of length to width of antennomeres III to XI about 2.9: 3.4: 3.5: 3.5: 3.5: 4.0: 4.0: 4.0: 4.9. Sternite VIII (Fig. 33) very small, weakly sclerotized subapically, setae along lateral and apical margins, spiculum short. Spermathecal receptaculum (Fig. 35) strongly swollen; pump narrow and strongly curved, apex narrowly rounded; spermathecal duct short and stout, shallowly projecting into receptaculum. Gonocoxae (Fig. 34) narrowly connected in middle, elongate, about 4.7 times longer than wide, slightly curved inwards at apical 1/4, with one short setae at apical 1/3, ten short and long setae located apically or subapically.

Distribution.

China (Yunnan).