Chaetocnema (Chaetocnema) simplicifrons ( Baly, 1876 ), 2016

Ruan, Yongying, Yang, Xingke, Konstantinov, Alexander S., Prathapan, Kaniyarikkal D. & Zhang, Mengna, 2019, Revision of the Oriental Chaetocnema species (Coleoptera, Chrysomelidae, Galerucinae, Alticini), Zootaxa 4699 (1), pp. 1-206 : 99-100

37. Chaetocnema (Chaetocnema) simplicifrons ( Baly, 1876)

( Fig. 58 )

Plectroscelis simplicifrons Baly, 1876: 594 . TL: China, “Kin Kiang” (i.e. ‘XinJiang’). TD: BMNH. Lectotype designated here.

Chaetocnema simplicifrons: Chen, 1934: 249 .

Distribution: China (Xinjiang, Jiangxi, Yunnan, Tibet), Vietnam, Nepal, India, Pakistan.

Host plants: Rubus sp.

Description: Body length: 1.65–1.80 mm. Body width: 1.01–1.04 mm. Ratio of elytron length (along suture) to width (maximum): 2.30–2.33. Ratio of pronotum width (at base) to length: 1.75–1.77. Ratio of length of elytron to length of pronotum (along middle): 2.59–2.61. Ratio of width of elytra at base (in middle of humeral calli) to width of pronotum at base: 1.08–1.10.

Dorsum black, without metallic luster. Dorsum and head not rugose. Antennae yellow brown, with distal antennomeres darker. Tibiae and tarsi yellow brown, pro- and mesofemora dark yellow brown. Metafemora dark brown.

Head hypognathous. Vertex raised, at higher plane than orbit. Frontal ridge narrow and convex. Frontolateral sulcus present. Nemerous punctures present on and below frontolateral sulcus. Suprafrontal sulcus poorly developed. Orbital, supraantennal sulci very deep. Ratio of width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 0.95–1.05. One large puncture bearing setae present on vertex on each side near eye. Several small punctures scattered on orbit on each side. Number of setae on clypeus: approximately 16. Number of setae on labrum: 6. Anterior margin of labrum almost straight at middle.

Pronotum rather convex, Pronotal punctures rugged, variable in size, with diameter 3–6 times smaller than distance between them. Pronotum without longitudinal impressions near basal margin. Pronotum depressed near basal margin. Deep row of large punctures at base of pronotum absent. Pronotal base convex, expanded posteriorly in middle. Lateral margins of pronotum slightly convex, converging forward. Anterolateral prothoracic callosity truncate, oblique and thick. Posterolateral prothoracic callosity poorly developed.

Elytra with slightly convex lateral sides. Elytral punctures larger than those on pronotum, arranged in single lines, including peri-scutellar row. Interspaces between striae of punctures smooth and glabrous. Number of rows of minute punctures on each interspace: 1–2. Humeral callus well developed.

Excavation on metatibia moderately deep. Large lateral denticle on metatibia obtuse, serration proximal to large lateral denticle absent.

Apex of aedeagus in ventral view narrowing gradually. Ventral longitudinal groove absent. Apical denticle in ventral view not prominent. Minute transverse wrinkles on ventral side absent. Aedeagus in lateral view almost straight at apex and middle, strongly curved near base.

Spermathecal receptacle pear-shaped. Spermathecal duct coiled several times. Spermathecal pump much short- er than receptacle, with cylindrical, narrowed apex. Vaginal palpus slightly narrowing from base till middle, thence approximately parallel sided. Anterior sclerotization of vaginal palpus slightly widening anteriorly. Posterior sclerotization longer than wide. Posterior sclerotization wider than anterior.

Types: Lectotype: 1 ( BMNH), labels: 1) Type H.T.; 2) China; 3) Baly Coll.; 4) Chaetocnema simplicifrons Baly , China; 5 ) Lectotype Chaetocnema simplicifrons ( Baly, 1876) Des. Ruan et al., 2016 .

Paralectotype: 1 (BMNH), labels: 1)Baly Coll.; 2) Paralectotype Chaetocnema simplicifrons ( Baly, 1876) Des. Ruan et al., 2016 .

Material: 2♀ ( IZCAS), China: Yunnan, Jinghong, Ganlanju , alt. 700m, 1957.III.21, Chaetocnema simplicifrons, Baly det. Chen ; 1♀ ( IZCAS), China: Yunnan, Damenglong , alt. 700m, 1957.IV.11, Chaetocnema simplicifrons, Baly det. Chen ; 6♀ ( IZCAS), China: Yunnan, Jingping , 21.IV.1956, alt. 420m, leg. Keren Huang et al .; 4♀ ( IZCAS), China: Yunnan, Jingping, Changpotou , leg. Keren Huang et al., 22.V.1956, alt. 1000m ; 4♂ ( IZCAS) ,

China: Sichuan, Chengdu , 11.VIII.1963, alt. 500m, NanKai University, leg. Huangguang Zhou; 1♀ ( IZCAS) , China, Tibet, 2015-VIII-29, Zhengzhong Huang leg.; 1♂ ( IZCAS) , Vietnam: Hanoi, Coll. L. BEDEL 1922, MUSEUM PARIS; 1♂ ( USNM) , Nepal: env., 08.V.2000, Kathmandu, Bonipa, agricultural fields, Konstantinov, Lingafelter, Volkovitch; 1♂ ( USNM) , India, Eastern Ghats Karnataka, 14km E. Tumkur , 13.XI.2003, 1170m, 13° 22'24" N, 77°12'05"E, leg. Konstantinov, Prathapan, Saluk, loan from USNMNH 20665634; 4♀ ( USNM) India, Assam, 10 mi N Tinsukia , in jungle, 5.IV.1944, D. E. Hardy, loan from USNMNH 20665634; 1 ( BMNH) , Pakistan, Jamalpur , 23.iv.68, Chinese paddy, CIE.A.2420, Pres by Comm Inst Ent, B. M. 1981–315, Chaetocnema simplicifrons Baly, 1876 , Det. Yongying Ruan, 2016 .

Remarks: This species resembles C. yaosanica , and C. basalis , but for the strongly raised vertex. It is also close to C. tristis and C. puncticollis . However, it can be distinguished from C. tristis by the smaller body size, and from C. puncticollis by the unusually convex pronotum and wider body.

Figures

FIGURE 58. Chaetocnema simplicifrons. A Habitus. B Pronotum and peri-scutellar area. C Head, lateral and frontal views (in lateral view, vertex strongly raised above the level of eye and orbit). D Aedeagus, ventral view. E Aedeagus, lateral view. F Apex of aedeagus, ventral view. G Vaginal palpi. H Spermatheca. I Pygidium (tergite 7) of female. J Tignum.