Chaetocnema (Chaetocnema) gracilis Motschulsky, 1858

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 : 56-58

15. Chaetocnema (Chaetocnema) gracilis Motschulsky, 1858

( Figs. 34 , 35 )

Chaetocnema gracilis Motschulsky, 1858: 107 . TL: India. TD: Moscow University??.

Chaetocnema minuta Jacoby, 1896: 271 , nec. Chaetocnema minuta Melsheimer, 1847 ; Lectotype designated here. Chaetocnema indica Weise, 1916: 39 . (new name for Chaetocnema minuta Jacoby, 1896 ); synonymized by Medvedev, 2006.

Distribution: China, Vietnam, Myanmar, Nepal, Bhutan ( Döberl, 2010), India, Pakistan ( Döberl, 2010); Australian Region: New Caledonia.

Host plants: Alternanthera sp. ( Amaranthaceae ) ( Reddy et al, 1980), Brassica campestris L. ssp. peckinensis (Lour) Olsson ( Khaire and Lawande, 1976) , Brassica oleracea Linn. var botrytis Linn. (Khire et al., 1986) , Brassica oleracea Linn. var capitata Linn. (Brassicaceae) (Khire et al., 1986), Firmiana colorata R.Br. (Sterculiaceae) ( Narayanaswamy et al., 1985), Lagerstroemia indica Linn.(Lythraceae) ( Govindan et al., 1986), “millets” ( Poaceae ) ( Kishore, 1996; Nair, 1986), Oryza sativa L. var. terrestris Makino (Gressitt & Kimotto) ; Sorghum vulgare Pers. (Poaceae) ( Mote and Ghule, 1989a, b).

Description: Body length 1.40–1.70 mm, body width 0.80–0.90 mm. Ratio of pronotum width (at base) to length: 1.70–1.80. Ratio of length of elytron to length of pronotum (along middle): 2.70–2.80. Ratio of width of elytra at base to width of pronotum at base (in middle of humeral calli): 1.15–1.20. Ratio of maximum width of elytra to maximum width of pronotum: 1.30–1.40.

Elytra usually bronzy or dark bronzy, sometimes red brown, with weak metallic luster. Color of pronotum usually different from that of elytra, bronzy, with greater metallic luster than elytra. Antennomeres 1–5 yellow, 5–11 brown. Pro- and mesofemora yellow, metafemora brown. Tibiae partially brown.

Head pro-hypognathous, bronzy, granulose. Frontal ridge slightly wider than antennal socket, convex. Frontolateral sulcus present. Frons with relatively long setae laterally. Vertex flat, situated on same level as orbit, with 9–13 shallow punctures on each side near eye.

Base of pronotum without longitudinal impressions. Deep row of large punctures at base of pronotum absent. Pronotal base strongly expanded in middle as in C. fusiformis . Area adjacent to mid basal margin of pronotum covered with punctures. Pronotum without shallow antebasal transverse impression. Lateral margins of pronotum slightly convex, converging forward. Anterolateral prothoracic callosity acutely produced forward. Posterolateral prothoracic callosity poorly developed. Diameter of pronotal punctures subequal to distance between adjacent punctures.

Elytra with convex sides. Scutellar row of punctures regular and single. Second to eleventh rows of punctures regular. Humeral callus poorly developed.

Metatibial excavation moderately deep. Large lateral denticle on metatibia sharp. Metatibial serration proximal to large lateral denticle present, sharp. Metatibia proximal to denticle in dorsal view convex. First metatarsomere cylindrical and long, as long as remaining tarsomeres together.

Ventral longitudinal ridge in middle of aedeagus absent. Apex of aedeagus abruptly narrowed.

Spermathecal pump much shorter than receptacle, with apex curved and narrowed. Spermathecal receptacle cylindrical. Receptacle basally wider than apically, with maximum width situated basally. Posterior sclerotization of tignum gradually narrowing, narrower than mid-section. Mid-section of tignum slightly curved. Anterior sclerotization of tignum wider than mid-section. Apex of vaginal palpus subtriangular, with convex lateral margin. Vaginal palpus narrowing from base to middle, thence slightly widening towards apex. Anterior sclerotization of vaginal palpus slightly narrowing anteriorly. Anterior end of anterior sclerotization nearly rounded. Posterior sclerotization longer than wide. Posterior sclerotization wider than anterior.

Types: Lectotype of Chaetocnema minuta Jacoby (= Chaetocnema indica Weise, 1916 ): 1♀, labels: 1) Bel- gaum. N; 2) Type; 3) Jacoby Coll. 1909–28 a; 4) Chaetocnema minuta Jacoby ; 5) Examined K. Prathapan 2005; 6) Lectotype Chaetocnema minuta Jacoby, 1896 , Des. Ruan et al., 2016.

Paralectotypes of Chaetocnema minuta Jacoby (= Chaetocnema indica Weise, 1916 ) (in BMNH): 1♀, labels: 1) Belgaum. N; 2) Type; 3) Chaetocnema minuta Jacoby ; 4) Andrewes Beguest 1922–221. Paralectotype Chaetocnema minuta Jacoby, 1896 , Des. Ruan et al., 2016. 2 specimens, labels: 1) Belgaum. N; 2) Coype; 3) Chaetocnema minuta Jacoby ; 4) H. E. Andrewes Beguest B.M. 1922–221. 5) Examined K. Prathapan 2005; 6) Paralectotype Chaetocnema minuta Jacoby, 1896 , Des. Ruan et al., 2016. 1 specimen, labels: 1) Belgaum. N; 2) H. E. Andrewes Beguest B.M. 1922–221; 3) Paralectotype Chaetocnema minuta Jacoby, 1896 , Des. Ruan et al., 2016.

Material: 2♂ 2♀ ( IZCAS), China, Damenlong, Yunnan, Chaetocnema indica det. Chen, 11.IV.1957; 4♂ 8♀ ( IZCAS), Vietnam, Tonkin, Hoa–binh, VII.1939, leg. A. de. Cooman; 2♂ 2♀ ( USNM), Myanmar, Tenasserim, MUS. PRAGENSE, Coll. Helfer, Chaetocnema indica Weise det. I. Lopatin, 1961; 1♂ 3♀ ( BMNH), Nepal, Dhunibesi, 22.VI.65, on paddy, Dept. Agric, CIE. A. 573, Coll. 155; 1♀ ( USNM), Nepal: env., 08.V.2000, Kathmandu, Bonipa, agricultural fields, Konstantinov, Lingafelter, Volkovitch; 1 ( BMNH), Nepal: 2070’, Kathmandu dist., 13–30/VII/1984, Malaise trap, BMNH(E),1984–136, coll. M. G. Allen, Chaetocnema gracilis (Motschlsky, 1858) , Det. Yongying Ruan, 2016; 13 ( BMNH), Nepal, 1350–2070m, Kathmandu, vi–vii/1984, Lt–col. M. G. Allen, Malaise trap, Chaetocnema gracilis Motschlsky, Det. Yongying Ruan, 2016 ; 1 ( BMNH), Nepal, 8800’, Kathmandu dist., Phulcoki, 27–31.v.1983, low herbage in open oak forest, Chaetocnema gracilis Motschlsky, Det. Yongying Ruan, 2016 ; 1♂ ( BMNH), India, Rajasthan, Bharatpur, 12.VIII.1989; 2♂ 3♀ ( USNM), South India, Easten Ghats Karnataka, Chikmagular , 15.XI.2003, leg. Konstantinov, Prathapan, Saluk; 1 ( BMNH), Chipurupalle, Vizagapatam Distr., India, R. S. Patuck, B. M. 1923–430, Chaetocnema indica Weise ; 3 ( BMNH), India, Rahuri, 18. ix. 1986, sorghum seedling, CIE A19195 , BMNH{F}, 2012–16; 2 ( BMNH), India, Dharwad, 13.VIII.1982, S. Hosur coll., Sp No. 28, a Sorghum , C.I.E. A.14269, Chaetocnema indica Weise , det. M. L. Cox, 1982, Pres by Comm Inst Ent, B. M. 1982–1; 7 ( BMNH), India, Mah. Phule, Agr. Univ., Rahuri, 18.IX.86, V. N. Mote, Sp. 3 on lvs. of, Sorghum seedlings CIE A19195 , Pres by Comm Inst Ent, B. M. 1987–1; 3 ( BMNH), H. L. Andrewes, Nilgiri Hills ( India), Andrewes, Bequest, B. M. 1922–221, Chaetocnema gracilis Motschlsky, Det. Yongying Ruan, 2016 ; 2 ( BMNH), Kanara ( India), Andrewes, Bequest, B. M. 1922–221; 1 ( BMNH), T. R. Bell, Khandesh ( India), Andrewes, Bequest, B. M. 1922–221, Chaetocnema gracilis Motschlsky, Det. Yongying Ruan, 2016 ; 1 ( BMNH), E. Coll. Laferte, N. India, 67.56, Chaetocnema gracilis Motschlsky, Det. Yongying Ruan, 2016 ; 1 ( BMNH), debris on beach, Pakistan, I. nr. Karachi, 16.XII.1951, INDIA.1952., T. Clay, B.M. 1952–143, Chaetocnema gracilis Motschlsky, Det. Yongying Ruan, 2016 ; 3♀ ( USNM), New Caledonia, 20m, Coumac, 6–12.I.1991, leg. Wiesner & Worm Chaetocnema indica det. Döberl, 1995; 1 ( BMNH), Brit. Mus. 1978–16, Chaetocnema gracilis Motschlsky, Det. Yongying Ruan, 2016 .

Remarks: Species concept is based on the original description provided by Motschulsky (1858).

In C. gracilis , body color varies considerably between specimens from different localities. Color of the elytra may be different from that of the pronotum in most cases.

Figures

FIGURE 34. Chaetocnema gracilis. A Habitus. B Pronotum. C Head, frontal view. D Aedeagus, ventral and lateral views. E Apex of aedeagus, ventral view. F Vaginal palpi. G Spermatheca. H Tignum.

FIGURE 35. Chaetocnema gracilis. A Male habitus (example for variation in color). B Head, frontal view. C Pygidium (tergite 7) of female.