Chaetocnema yulongensis Ruan, Konstantinov & Yang

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 : 64-68

Taxon classification Animalia Coleoptera Chrysomelidae

Chaetocnema yulongensis Ruan, Konstantinov & Yang sp. n. Figure 4

Etymology.

We named this species after the "Yulong snow mountain" in Yunnan province where the holotype was collected.

Host plants.

Unknown.

Distribution.

China, Yunnan.

Diagnosis.

Chaetocnema yulongensis and Chaetocnema deqinensis are extremely alike externally, but differ significantly in the shape of the median lobe. In Chaetocnema yulongensis , maximal curvature of the median lobe in lateral view is situated medially; apical end of the median lobe is narrowly rounded; the suprafrontal sulcus is obtuse in the middle. In Chaetocnema deqinensis , the maximal curvature of the median lobe is situated apically; the apical end of the median lobe is broadly rounded; the superfrontal sulcus is absent in the middle.

Description.

Body length: 1.66-2.15 mm, without head: 1.46-1.99 mm. Body width: 0.92-1.17 mm. Length of antenna to length of body: 0.60-0.61 mm. Elytron length (along suture) to width (maximum): 2.54-2.65. Pronotum width (at base) to length: 1.72-1.73. Length of elytron to length of pronotum (along middle): 3.25-3.30. Width of elytra at base (in middle of humeral calli) to width of pronotum at base: 1.10-1.15. Maximum width of elytra to maximum width of pronotum: 1.41-1.43.

Color of elytron copperish, similar to color of pronotum and head. Antennomere 1 partly dark brown. Antennomeres 2-4 completely yellow. Antennomere 5 partly brown. The remaining antennomeres brown. Protibia partly brown. Meso- and metatibia partly brown. Femora brown.

Head hypognathous. Frontal ridge between antennal sockets narrow and convex. Frontolateral sulcus present. Orbital sulcus deep. Suprafrontal sulcus deep laterally, shallow in middle. Suprafrontal sulcus obcordate. Ratio of width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 0.86-0.90. Width of orbital sulcus to width of frontolateral sulcus: 0.54-0.61. Numbers of punctures on vertex: 8-12. Numbers of punctures on orbit: 2. Numbers of hairs along frontolateral sulcus: 8-9. Numbers of hairs on frons (triangle area surrounded by frontolateral sulcus and clypeus): 0. Numbers of hairs on clypeus: 7. Numbers of hairs on labrum: 6. Anterior margin of labrum slightly concave in middle.

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

Elytra with convex sides. All rows of punctures regular and single including scutellar row. Elytral humeral callus well developed. Interspaces between stria of punctures smooth and glabrous. Numbers of lines of minute punctures on each interspace: 2.

First male protarsomere slightly larger than second one. First male protarsomere, length to width ratio: 1.64-1.70. First and second male protarsomeres, length to length ratio: 1.57-1.62. First and second male protarsomeres, width to width ratio: 1.03-1.04. First male protarsomere, width at apex to width at base: 1.53-1.58. Length of metatibia to distance between denticle and metatibial apex: 2.38-2.41. Large lateral denticle on metatibia sharp. Metatibial serration proximal to large lateral denticle present, obtuse. First male metatarsomere, length to width ratio: 2.63-2.73. First and second male metatarsomeres, length to length ratio: 1.91-2.04. First and second male metatarsomeres, width to width ratio: 0.93-0.96. Third and fourth male metatarsomeres, length to length ratio: 0.60-0.61.

Apical third of median lobe narrowing with polygonal line on sides. Apical part in ventral view narrowing abruptly. Ventral longitudinal groove absent. Apical denticle in ventral view absent. Minute transverse wrinkles of ventral side absent. Median lobe in lateral view evenly and slightly curved with apex sinuated. Maximal curvature in lateral view situated medially.

Spermathecal receptacle pear-shaped. Basal part of spermathecal duct straight. Spermathecal pump much shorter than receptacle. Apex of spermathecal pump cylindrical. Spermathecal pump attached to middle of receptacle top. Basal part of receptacle wider than apical. Posterior sclerotization of tignum spoon-shaped, wider than mid section. Mid section of tignum nearly straight. Anterior sclerotization of tignum narrower than mid section. Apex of vaginal palpus subdeltoid, with lateral sides slightly arching. Sides of mid part of vaginal palpus (before apex) narrowing from base, slightly widening towards apex. Anterior sclerotization of vaginal palpus narrowed at apex and base, widened at middle. Anterior end of anterior sclerotization narrowly rounded. Width of posterior sclerotization smaller than width of anterior sclerotization.

Type material.

Holotype: 1♂, 1) China: Yulong Mountain, Lijiang, Yunnan, alt.2700m. 2) 1984.VII.21, Leg.Shuyong Wang; 3) Holotype, Chaetocnema yulongensis sp. n., Des. Ruan, Konstantinov, Yang. 2014. (IZCAS)

Paratypes (all in IZCAS, except those that are indicated as USNM or SYSU): 8♂10♀, China: Yulong Mountain, Lijiang, Yunnan, alt.2700m, 1984.VII.21, Leg.Shuyong Wang, 1♀ USNM; 2♂5♀, Gezha, Zhongdian, Yunnan, alt.3150m, 1981.VIII.4, Leg.Shuyong Wang, 1♂ USNM; 1♂5♀, Xiaozhongdian, Yunnan, alt.2500-3200m, 1984.VIII.5, Leg.Shuyong Wang; 4♀, Lidiping,Weixi, Yunnan, alt.3400m, 1984.VIII.13, Leg.Shuyong Wang, 1♀ USNM); 1♂, Fengyi, Yunnan, alt.2000m, 1955.VI.1, Leg.B. Popov; 2♂, Xiaguan, Yunnan, alt.2050m, 1955.V.30, Leg.B. Popov; 6♂, Kunming, Yunnan, alt.1900m, 1940.VII.4, Leg.J. L. Gressitt (SYSU).