Chaetocnema (Udorpes) ingenua ( Baly, 1876 )

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 : 160-162

66. Chaetocnema (Udorpes) ingenua ( Baly, 1876)

( Fig. 93 )

Plectroscelis ingenua Baly, 1876: 594 . TL: China. TD: BMNH.

Chaetocnema japonica Jacoby, 1885: 732 . TL: Japan. TD: BMNH. Synonymized by Gressitt & Kimoto, 1963: 780. Chaetocnema aurifrons Jacoby, 1885: 733 . TL: Japan. TD: BMNH. Synonymized by Kimoto & Takizawa 1994: 320. Chaetocnema fulvipes Jacoby, 1885: 732 . TL: Japan. TD: BMNH. Synonymized by Gressitt & Kimoto, 1963: 780. Chaetocnema ingenua: Weise, 1922: 130 .

Chaetocnema micans Palij, 1961: 11 (nomen nudum).

Chaetocnema ogloblini Palij, 1970: 197 . TL: North–East China. TD: ZIN. Synonymized by Konstantinov et al., 2011.

Distribution: China (Heilongjiang, Jilin, Inner Mongolia, Hebei, Shanxi, Shaanxi, Shandong, Henan, Gansu, Jiangsu, Hubei, Jiangxi, Hunan, Fujian, Sichuan, Yunnan), Mongolia, Russia, Korea, Japan, India, Sri Lanka.

Host plants: Oryza sativa , Triticum aestivum , Zea mays , Setaria italica ; Carex kobomugi ( Chûjô & Kimoto, 1961) ; Digitaria adscendens ( Ohno & Hirano, 1970) , Panicum miliaceum ( Palij, 1961) .

Description: Body length: 1.90–2.40 mm. Body width: 0.90–1.30 mm. Ratio of length of antenna to length of body: 0.55–0.65 mm. Ratio of elytron length (along suture) to width (maximum): 2.30–2.40. Ratio of pronotum width (at base) to length: 1.60–1.70. Ratio of length of elytron to length of pronotum (along middle): 2.95–3.10. Ratio of width of elytra at base (in middle of humeral calli) to width of pronotum at base: 1.10–1.15.

Dorsum variable, usually blue green to coppery, varied. Antennomeres 1–5 yellow to light brown, 6–11 brown to dark brown. Tibiae yellow to light brown. Pro- and mesofemora light brown. Metafemora dark brown with metallic luster.

Head hypognathous. Frontal ridge flat, not wide. Frontolateral sulcus absent. Suprafrontal sulcus poorly developed. Orbital, supraorbital sulci obsolete, covered with punctures. Ratio of width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 1.55–1.65. Punctures on frons, orbit and vertex extremely close. Number of setae on clypeus: more than 20. Number of setae on labrum: 6. Anterior margin of labrum straight or slightly convex at middle.

Pronotum without longitudinal impressions near basal margin. Deep row of large punctures at base of pronotum absent. Pronotal base evenly convex. Lateral margins of pronotum slightly convex, converging forward. Anterolateral prothoracic callosity poorly developed. Posterolateral prothoracic callosity poorly developed. Pronotal punctures close, diameter of pronotal punctures 1 to 2 times smaller than the distance between them.

Elytra convex laterally. Elytral punctures larger than those on pronotum. Scutellar punctures form 2 to 3 (occasionally 4) confused rows, remaining rows of elytral punctures regular and single. Interspaces between rows of punctures smooth and glabrous. Number of rows of minute punctures on each interspace: 2. Humeral callus well developed.

First male protarsomere slightly larger than second. Excavation on metatibia moderately deep.

Apex of aedeagus in ventral view narrowing abruptly. Ventral longitudinal groove well developed, wide in distal half, narrowing basally. Apical denticle in ventral view extremely wide, with apex almost truncate or slightly concave. Minute transverse wrinkles on ventral groove present throughout. Aedeagus in lateral view unevenly curved, straight near apex and base, maximum curvature situated basally.

Types: Chaetocnema ingenua : Lectotype (1 female, BMNH): 1) Type, H.T., 2) Baly Coll., 3) Plectroscelis ingenua Baly , China, 4) [reverse side of label illegible: Trans......., Dec: 1876, 1–594, Type] 5 ) Lectotype Chaetocnema ingenua Baly des. A. S. Konstantinov et al. 2009.

Chaetocnema aurifrons : Lectotype (1 female, BMNH): 1) Type H.T., 2) Japan, G. Lewis, 1910–320, 3) Chaetocnema aurifrons Jac. , 4) Lectotype Chaetocnema aurifrons Jacoby des. A. Konstantinov 2010, 5) Chaetocnema ingenua Baly det. A. Konstantinov 2010 (BMNH). Chaetocnema fulvipes : Lectotype female: 1) Type H.T., 2) Japan, G. Lewis, 1910– 320, 3) Chaetocnema fulvipes Jac. , 4) Lectotype Chaetocnema fulvipes Jacoby des. A. Konstantinov 2010, 5) Chaetocnema ingenua Baly det. A. Konstantinov 2010.

Chaetocnema japonica : Lectotype (1 female, BMNH): 1) Type H.T., 2) Japan, G. Lewis, 1910– 320, 3) Chaetocnema japonica Jac. , 4) Lectotype Chaetocnema japonica Jacoby des. A. Konstantinov 2010, 5) Chaetocnema ingenua Baly det. A. Konstantinov 2010; Paralectotype (1, BMNH): 1) Japan Lewis; 2) Jacoby coll. Paralectotypes (2, BMNH): 1) Japan, G. Lewis, 1910–320. The rest of the labels are the same as lectotype.

Chaetocnema ogloblini : Paratypes: 1 ( ZIN), 1) Blagoveschensk, 20.VI.27 , 2) Paratypus, Ch. ogloblini Palij ; 1 ( ZIN), 1) Blagoveschensk, 28.VI.27, na prose, 2 ) Paratypus, Ch. ogloblini Palij ; 1 ( ZIN), 1) na prose, Amurskaya opyt. stantsiya, 19.VII , 2) Paratypus, Ch. ogloblini Palij ; 9 ( ZIN), 1) Voroshilov, Ussur. 15.VI.31, T. Samojlov, 2 ) Paratypus, Ch. ogloblini Palij.

Material: 1♂ ( USNM), China, Tsinan , Shantung, A. P. Jacot, Sept. 10.1922, Chaetocnema ingenua det. Yongying Ruan, 2016 ; 1♂ 1♀ ( IZCAS), China: Shanghai, IX.1951 ; 1♂ ( IZCAS), Tongmuguan, Wuyi Mountain , Fu- jian ( China), alt. 1100m, 11.X.1997, leg. Jiashe Wang ; 1♂ ( IZCAS), China: Shaanxi, Foping, Liangfengya , alt. 1900–2100, 24.VII.1998, leg. Jun Chen ; 1♂ ( IZCAS), China: Hunan, Sangzhi, Tianping Mountain , alt. 1370, 15.VIII.1988, leg. Jun Chen ; 23 ( IZCAS), China: Sichuan, Wushang, Jiangdong village , 2.VIII.1993, alt. 140m, leg. Xingke Yang et al.; 25♂ 16♀ ( IZCAS), China: Yunnan, Weixi, Pantiange , alt. 2920m, 17.VII.1981, leg. Shuyong Wang.

Remarks: Color is highly variable in C. ingenua , even amongst specimens collected at the same locality and season. The following variants of metallic colors were observed in our study: 1) dorsum entirely coppery; 2) metallic blue pronotum and elytra, coppery head; 3) metallic green pronotum and elytra, coppery head; 4) metallic purple pronotum and elytra, coppery head.

Variation was also observed in the structure of aedeagus. Transverse wrinkles on the ventral side of the aedeagus varied considerably in prominence. Apical denticle too varied in length. This species is close to C. modiglianii and C. bella . In C. modiglianii , aedeagus in ventral view is robust and basally distinctly wider compared to the same in C. ingenua . Punctation on vertex is denser in C. ingenua compared to C. bella . In C. bella , lateral margins of promotum are almost straight, or slightly rounded and the diameter of pronotal punctures 2–4 times smaller than the distance between adjacent punctures. In C. ingenua , lateral margins of pronotum are convex and distinctly converge forward and the pronotal punctures are 1–2 times smaller than the distance between adjacent punctures. Spermathecal receptacle is widest in middle in C. bella , while it is distinctly narrowed in middle in C. ingenua .

Figures

FIGURE 93. Chaetocnema ingenua. A Male habitus. B Pronotum. C Head, frontal view. D Aedeagus, lateral view. E Aedeagus, ventral view. F Apex of aedeagus, ventral view. G Vaginal palpi. H Spermatheca. I Pygidium (tergite 7) of female. J Tignum.