Chaetocnema (Udorpes) cognata 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 : 143-145

58. Chaetocnema (Udorpes) cognata Baly, 1877

( Figs. 81 , 82 )

Chaetocnema cognata Baly, 1877: 168 . TL: India. TD: BMNH. Lectotype designated here.

Chaetocnema squarrosa Baly, 1877: 169 . TL: India. TD: BMNH. synonymized by Maulik, 1926: 217. Lectotype designated here.

Distribution: China, Thailand, India, Sri Lanka, Pakistan.

Host plants: Unknown.

Description: Body length: 1.70–2.00 mm, body width: 0.95–1.05 mm. Ratio of elytron length at suture to maximum width: 2.20–2.25. Ratio of pronotum width at base to length at middle: 1.55–1.65. Ratio of length of elytron at suture to length of pronotum at middle: 2.50–2.55. Ratio of width of elytra at base to width of pronotum at base: 1.00–1.05. Ratio of maximum width of elytra to maximum width of pronotum: 1.30–1.40.

Dorsum bronzy. Antennomeres 1–5 completely yellow, 5–11 brown, apical ones darkened. Tibiae yellow. Tarsi yellow, slightly darkened distally. Pro- and mesofemur yellow brown. Metafemur dark brown.

Head hypognathous. Frontal ridge wide and flat. Frons covered with closely placed punctures, larger than those on vertex. Ratio of width of frontal ridge between outer ridge of antennal sockets to width of antennal socket (including surrounding ridge): 1.90–2.10. Frontolateral sulcus absent. Suprafrontal sulcus deep with a pit in middle. Frons evenly covered with large and closely placed punctures and with relatively short, white setae. Vertex flat, situ- ated on same level as orbit. Vertex densely and evenly covered with small punctures.

Base of pronotum without short longitudinal impressions. Pronotal base evenly convex. Deep row of large punctures at base of pronotum absent. Area adjacent to mid-basal margin of pronotum covered with punctures. Anterolateral prothoracic callosity moderately developed, truncate and oblique. Lateral margins of pronotum slightly convex, with maximum width near middle. Posterolateral prothoracic callosity projecting up to lateral margin of pronotum. Diameter of pronotal punctures 1–2 times smaller than distance between punctures.

Humeral calli weak. Hind wings reduced, not longer than elytra. Elytra with convex lateral sides. Scutellar row of elytral punctures usually paired (occasionally single or tripled) and confused. Second to eleventh rows of elytral punctures regular.

First protarsomere slightly larger in male. First male protarsomere length to width ratio: 1.10–1.20. Excavation on metatibia not deep. Large lateral denticle on metatibia obtuse. Metatibial serration proximal to large lateral denticle absent.

Aedeagus parallel-sided in ventral view. Apex of aedeagus in ventral view narrowing abruptly. Ventral longitudinal groove of aedeagus strongly developed, nearly parallel sided. Ventral longitudinal ridge in middle of aedeagus absent. Apical denticle of aedeagus in ventral view well-differentiated, narrow, apparently truncate. Minute, transverse wrinkles present at base of ventral side of aedeagus. Aedeagus in lateral view curved at base, straight at apex.

Spermathecal pump much shorter than receptacle, with apex flattened. Spermathecal receptacle sinuated. Maxi- mum width of receptacle situated at middle. Receptacle basally as wide as apically. Vaginal palpus slightly narrowing from base till apex, thence approximately parallel-sided. Anterior sclerotization of vaginal palpus slightly widening anteriorly. Posterior sclerotization longer than wide. Posterior sclerotization wider than anterior.

Types: Chaetocnema cognata Baly. Lectotype (1♂, BMNH), labels: 1) Type H.T.; 2) Baly Coll.; 3) Chaetocnema cognata Baly ; 4) Examined K. Prathapan 2005; 5) SYNTYPE; 6) Examined Ruan Yongying 2014; 7) Lectotype Chaetocnema cognata Baly, 1877 Des. Ruan et al., 2016 .

Chaetocnema squarrosa Baly. Lectotype (1♀, BMNH), labels: 1) Type H.T.; 2) Baly Coll.; 3) Chaetocnema cognata Baly ; 4) Examined K. Prathapan 2005; 5) Lectotype Chaetocnema squarrosa Baly, 1877 Des. Ruan et al., 2016 .

Material: 2♀ ( BMNH), Baly Coll. (probably, these two specimens are also part of the materials used by Baly in origiginal description) ; 1♂, Bangkok ( Thailand), Siam, Nov.1924, H.M. Smith, collected at night, Chaetocnema sp. C. R. Basu det. , Chaetocnema cognata det. Yongying Ruan, 2016; 1 ( BMNH), Thailand, Nan Province, Lainan, 22–23.ix.2012, cabbage farm, 18.579°N, 100.757°E, LN3 Light trap, leg. D. L. J. Quicke, BMNH(E) 2015–75 ; 1♀ ( BMNH), India, W. Almora Divn, Kumaon U.P., III.1917, H. G. O., H. G. Champion Coll., B. M. 1953–156 ; 1♀ ( BMNH), India, at light, Bihar Prov., Ranchi, Namkum, 1928 ; 1♂ ( USNM), India, Bombay, JC Bridwell coll., 16.IX.1924; 4, West Bengal ( India), Singur, Nasibpur, May–June 1971, Oppenheimer , Chaetocnema sp. C. R. Basu det. , Chaetocnema cognata det. Yongying Ruan, 2016; 1♂ ( BMNH), Ceylon, G. Lewis. 1910–320; 3, Pakistan, Lahore, July 1958, light trap, Chaetocnema sp. C. R. Basu det. , Chaetocnema cognata det. Yongying Ruan, 2016. 1 ( BMNH), 67.56, Chaetocnema cognata Baly, 1877 , Det. Yongying Ruan, 2016.

Remarks: This species is extremely similar to C. afghana based on external characters, however, they obviously differ from each other by the shape of aedeagus. In C. cognata , peri-scutellar punctures are usually paired, reaching the middle of elytra; while in C. afghana , peri-scutellar punctures are usually single to slightly geminate (with fewer punctures than in C. cognata ), not reaching the middle of elytra. It also resembles C. eastafghanica in the general body shape, however, they can be well differentiated by the punctation on head and the shape of aedeagus.

Figures

FIGURE 81. Chaetocnema cognata. A Lectotype, habitus. B None-type specimen, habitus. C–D Aedeagus, ventral and lateral views. E Apex of Aedeagus, ventral view. F Vaginal palpi. G Spermatheca. H Pygidium (Tergite 7) of female.

FIGURE 82. Chaetocnema cognata. A Male habitus. B Female habitus. C Pronotum. D Head, frontal view.