Chaetocnema (Udorpes) malayana Baly, 1877

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 : 166-168

69. Chaetocnema (Udorpes) malayana Baly, 1877

( Fig. 96 )

Chaetocnema malayana Baly, 1877: 318 . TL: Malaysia. TD: BMNH. Lectotype designated here.

Chaetocnema birmanica Jacoby, 1892: 939 . TL: Myanmar. TD: BMNH. (Syn. Nov.) Lectotype designated here.

Distribution: China: Taiwan, Yunnan ( Ruan & Yang, 2015), Vietnam, Thailand, Myanmar, Malaysia.

Host plants: Unknown.

Description: Body length 2.20–2.55, body width 1.10–1.30. Ratio of elytron length (along suture) to width (maximum): 2.50–2.60. Ratio of pronotum width (at base) to length: 1.40–10.45. Ratio of length of elytron to length of pronotum (along middle): 2.50–2.60. Ratio of width of elytra at base to width of pronotum at base (in middle of humeral calli): 1.15–1.25. Ratio of maximum width of elytra to maximum width of pronotum: 1.30–1.40.

Dorsum usually metallic green to bronzy, occasionally coppery. Antennae slender, passing beyond humeral callus. Antennomeres 1–4 yellow, 5–11 yellow brown to dark brown. Pro- and mesotibia partially brown. Metatibia yellow brown. Pro- and mesofemora light brown. Metafemora brown.

Head hypognathous. Frontal ridge wide and flat. Frontolateral sulcus absent. Suprafrontal sulcus deep, obcordate. Ratio of width of frontal ridge to width of antennal socket (counting surrounding ridges): 2.10–2.20. Frons evenly covered with relatively short white setae. Vertex flat, situated on same level as orbit. Vertex densely and evenly covered with punctures.

Base of pronotum without short longitudinal impressions. Deep row of large punctures at base of pronotum absent. Pronotal base only slightly convex. Area adjacent to mid basal margin of pronotum covered with punctures. Pronotum without shallow antebasal transverse impression. Lateral margins of pronotum convex with maximum width near base. Anterolateral prothoracic callosity poorly developed, truncate, facing anterolaterally. Posterolateral prothoracic callosity poorly developed. Diameter of pronotal punctures slightly larger than distance between adjacent punctures.

Elytra with convex lateral sides. Peri-scutellar punctures tripled. Besides scutellar row, there are 15–16 regular rows of punctures on each elytron, extremely closely placed. Humeral callus well developed.

First male protarsomere extremely enlarged. First and second male protarsomeres, length to length ratio: 1.30– 1.40. First and second male protarsomeres, width to width ratio: 1.70–1.80. First male protarsomere, maximum width to width at base ratio: 1.90–2.00. Large lateral denticle on metatibia obtuse. Metatibial serration present, obtuse.

Apex of aedeagus in ventral view narrowing abruptly. Ventral surface of apex of aedeagus deeply concave. Ventral longitudinal groove in apical half wide, narrowing towards basal opening. Apical denticle of aedeagus in ventral view well differentiated, short, apex truncate. Apical denticle of aedeagus in lateral view strongly curved ventrally. Minute transverse wrinkles on basal part of ventral side of aedeagus absent. Aedeagus in lateral view evenly and slightly curved.

Spermathecal pump much shorter than receptacle. Apex of spermathecal pump flattened. Spermathecal receptacle sinuate. Maximum width of receptacle situated at apex. Anterior sclerotization of tignum wider than mid-section. Apex of vaginal palpus rounded. Vaginal palpus parallel-sided in middle. Anterior sclerotization of vaginal palpus slightly widening anteriorly. Posterior sclerotization about as wide as long. Posterior sclerotization obviously wider than anterior.

Types: Chaetocnema malayana Baly , Lectotype: 1 (BMNH), 1) Type H. T.; 2) Malaysia, Archipelago; 3) Baly, Coll.; 4) Chaetocnema malayana Baly , Malaysia, Archipelago; 5) Lectotype Chaetocnema malayana Baly, 1877 Des. Ruan et al., 2016 .

Chaetocnema birmanica Jac. Holotype: ♂ (BMNH), labels: 1) Type H.T.; 2) Bangoon Birmania Fea. XII 1888; 3) Jacoby Coll. 1909–28 a; 4) Chaetocnema birmanica Jac.

Material: 1♂ ( USNM), Thailand, Nakhon, Ratchasima Prov. , 9km SE Non Sung, 9.III.1971, P. & P. Spangler ; 2♂ ( USNM), Myanmar, Tenasserim , MUS. PRAGENSE, Coll. Helfer, Chaetocnema concinnipennis det. I. Lopatin , 1961; 1♀ ( USNM), India, New Delhi, 8.VII.1967, leg. K. E. Gibson, light trap ; 1 ( BMNH), India, with Morus seed, X.6.36, EQ#045164, 36: 31866, PrinceCdl .

Remarks: C. malayana resembles C. concinnipennis , it is very easy to confuse these two species. However, in C. concinnipennis , apical denticle of aedeagus is absent in ventral view, while the same is distinctly developed in C. malayana . Punctures on dorsum in C. malayana is much smaller and distantly placed compared to those in C. concinnipennis .

Figures

FIGURE 96. Chaetocnema malayana. A Male habitus. B Pronotum and peri-scutellar area. C Head, frontal view. 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.