Chaetocnema semicoerulea (Koch)

Ruan, Yongying, Konstantinov, Alexander S., Ge, Siqin & Yang, Xingke, 2014, Revision of Chaetocnemasemicoerulea species-group (Coleoptera, Chrysomelidae, Galerucinae, Alticini) in China, with descriptions of three new species, ZooKeys 463, pp. 57-74 : 59-60

Taxon classification Animalia Coleoptera Chrysomelidae

Chaetocnema semicoerulea (Koch) Figure 1

Chaetocnema semicoerulea Koch, 1803: 40 (type locality: Germany, Rheinland, "Kusel und Meisenheim"; type missing teste Doguet, 1994); as Haltica .

Chaetocnema saltitans Stephens, 1831: 327 (type locality: “Suffolk”; type depository: unknown); Weise 1886: 760 (synonymized).

Chaetocnema meridionalis Allard, 1859: cv (type locality: "France méridionale”; type depository: unknown); as Plectroscelis ; Heikertinger 1951: 211 (synonymized).

Chaetocnema saliceti Weise, 1886: 758 (as variety of semicoerulea ; type locality: not given; type depository: ZMHB); Heikertinger 1951: 211 (synonymized).

Chaetocnema femoralis Weise, 1886: 758 (as variety of semicoerulea ; type locality: not given; type depository: ZMHB); Heikertinger 1951: 211 (synonymized).

Distribution.

China (Heilongjiang); Russia [Siberia ( Heikertinger 1951), Far East ( Bukejs 2008)]; Middle Asia ( Heikertinger 1951); Europe ( Konstantinov et al. 2011).

Host plants.

Salix alba , Salix purpurea , Salix triandra , Salix incana , Salix viminalis , Calamagrostis sp., Phalaris sp. (Heikertinger, 1925); Salix alba , Salix purpurea , Salix triandra , Salix viminalis , Salix elaeagonos (Doguet, 1994); Salix alba , Salix purpurea (Fogato & Leonardi, 1980).

Description.

Body length: 2.05-3.00 mm, without head: 2.08-2.70 mm; body width: 1.24-1.67 mm. Ratio of elytron length at suture to maximum width: 2.26-2.46. Ratio of pronotum width at base to length at middle: 1.61-1.65. Ratio of length of elytron at suture to length of pronotum at middle: 3.13-3.16. Ratio of width of both elytra at base to width of pronotum at base: 1.15-1.16.

Elytron bronzish, blueish or copperish. Pronotum bronzish, greenish or copperish. Antennomere 1-2 completely yellow. Antennomeres 3-4 completely yellow or partly brown. The remaining antennomeres brown. Tibia and tarsi yellow. Pro- and meso-femur dark yellow. Metafemur brown. Tarsi dark yellow.

Head hypognathous. Frontal ridge between antennal sockets narrow and convex. Frontolateral sulcus present. Orbital sulcus deep. Suprafrontal sulcus relatively deep, well-defined, retuse. Ratio of width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 1.35-1.45. Vertex flat, situated on same level as orbit. Surface of vertex covered with 15-20 punctures next to each eye.

Base of pronotum with two longitudinal impressions. Deep row of large punctures at base of pronotum present on sides, lacking in middle. Pronotal base evenly convex. Sides of pronotum slightly convex with maximum width near base. Anterolateral prothoracic callosity protruding laterally forming a round angle. Posterolateral prothoracic callosity poorly developed. Diameter of pronotal punctures 2-4 times smaller than distance between them.

Elytra with convex sides. All rows of punctures of elytra regular. Elytral humeral callus well-developed. Interspace between stria of punctures on the elytra smooth. Numbers of lines of minute punctures on each interspace: 2-3.

First male protarsomere length to width ratio: 2.20-2.25. First and second male protarsomeres length to length ratio: 1.13-1.19. First and second male protarsomeres width to width ratio: 1.61-1.67. Length of metatibia to distance between denticle and metatibial apex: 2.37-2.45. Large lateral denticle on metatibia sharp. Metatibial serration proximal to large lateral denticle present, sharp. First male metatarsomere length to width ratio: 2.97-3.06. First male protarsomere maximum width to width at base ratio: 2.12-2.19. First and second male metatarsomeres length to length ratio, 1.71-1.78. First and second male metatarsomeres width to width ratio: 1.00-1.06. Third and fourth male metatarsomeres length to length ratio: 1.54-1.59.

Apical part of median lobe narrower than middle. Apical part in ventral view narrowing gradually with polygonal line on sides. Ventral longitudinal groove poorly developed, shallow or absent. Apical and basal parts of longitudinal groove usually subequal in width, wider than middle. Apical denticle in ventral view absent. Minute transverse wrinkles on ventral side present. Median lobe in lateral view sinusoidal near apex with maximal curvature situated medially.

Spermathecal receptacle pear-shaped. Spermathecal pump much shorter than receptacle. Apex of spermathecal pump cylindrical. Spermathecal receptacle piriform. Spermathecal pump attached to middle of receptacle top. Maximum width of receptacle situated at about middle. Basal part of receptacle wider than apical. Posterior sclerotization of tignum spoon shaped, wider than midsection. Midsection of tignum curved. Sides of midpart of vaginal palpus narrowed. Anterior end of anterior sclerotization narrowly rounded. Length of posterior sclerotization greater than width. Width of anterior sclerotization greater than width of posterior sclerotization.

Material.

1♂, China, Wuyiling, Yichun, Heilongjiang, 31.VIII.1970 (IZCAS).

Remarks.

Chaetocnema semicoerulea from the Palearctic Region has been recently revised by Konstantinov et al. (2011). This species is recorded in China for the first time. Only found one male specimen was found in China with all the characters in accordance with the European specimens that are available for study except the reduced body size (2.05 mm in body length).