Chaetocnema (Udorpes) glabra Ruan, Konstantinov & Yang, 2019

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 : 154-156

64. Chaetocnema (Udorpes) glabra Ruan, Konstantinov & Yang , New Species

( Figs. 88 , 89 , 90 )

Etymology: This species is named after its ovate body and smooth surface. Specific epithet is a noun in apposition.

Diagnosis: C. glabra sp. nov. is a flightless species, with hind wings and elytral calli absent. It differs from other Chaetocnema species in Oriental Region by the very short antennae, extremely wide inter-antennal space (wider than diameter of eye) and the absence of hind wings. Intriguingly, it is morphologically close to the species in C. denticulata species group (White, 1993) from North America with the unique frontal characters; it may be differentiated from them by the shape of aedeagus and absence of hind wings.

Distribution: India, Sri Lanka.

Host plants: Unknown.

Description: Body length: 1.80–2.00 mm. Body width: 1.00– 1.05 mm. Antennae extremely short, not reaching humerus. Ratio of length of antenna to length of body: 0.40–0.42. Ratio of elytron length (along suture) to width (maximum): 2.35–2.40. Ratio of pronotum width (at base) to length: 1.70–1.72. Ratio of length of elytron to length of pronotum (along middle): 2.40–2.42. Ratio of width of elytra at base (in middle of humeral calli) to width of pronotum at base: 0.98–1.02.

Dorsum dark bronzy. Antennomeres 1–6 yellow brown, 7–11 brown. Tarsi and tibiae yellow brown. Pro- and mesofemora yellow brown. Metafemora red brown.

Head hypognathous. Frontal ridge wide and flat. Ratio of width of frontal ridge to width of antennal socket: 3.80–4.00. Frontolateral, suprafrontal sulci absent, frontal ridge merge with vertex, with a pit in middle. Orbital, supraantennal sulci moderately developed, straight and oblique. Frons covered with a few to dozen large and irregularly placed punctures. Vertex flat, situated on same level as orbit. Vertex densely and evenly covered with small punctures, with a narrow longitudinal impunctate area in middle.

Base of pronotum without short longitudinal impressions. Pronotal base evenly convex. Deep row of large punctures at base of pronotum absent. Narrow area adjacent to mid-basal margin of pronotum impunctate. Anterolateral prothoracic callosity poorly developed, invisible from above. Lateral margins of pronotum slightly convex, with maximum width basally. Posterolateral prothoracic callosity poorly developed. Diameter of pronotal punctures small, 3–5 times smaller than distance between adjacent punctures.

Humeral calli and hind wings absent. Elytra with convex lateral sides. Scutellar row of elytral punctures single. Second to eleventh rows of elytral punctures regular. Elytral interspaces between puncture rows not costate.

First protarsomere a little larger in male than in female. Excavation on metatibia deep. Large lateral denticle on metatibia acute. Metatibial serration proximal to large lateral denticle absent.

Aedeagus parallel-sided. Apex of aedeagus in ventral view narrowing gradually. Ventral longitudinal groove of aedeagus moderately to poorly developed. Ventral longitudinal ridge in middle of aedeagus absent. Apical denticle of aedeagus in ventral view well differentiated, narrow, almost truncate apically. Minute, transverse wrinkles absent on ventral side of aedeagus. Aedeagus in lateral view evenly curved.

Spermatheca with receptacle sinuated. Spermathecal pump much shorter than receptacle, with apex flattened. Maximum width of receptacle situated near base. Receptacle basally wider than apically. 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 narrower than anterior.

Type: Holotype: ♂ ( BMNH): 1) India, Bandra, Dr. Jayakar, 1905–152, 2 ) Holotype; 3) Chaetocnema glabra sp. nov. des. Yongying Ruan, 2016.

Paratypes: 1♀ ( USNM), 1) Sri Lanka, Anu. Dist. Padaviya, Antiquities Site, 20–23.VII.1978, Collectors: K. V. Krobein T. Wijesime, V. Kulasekare, L. Jayawickrema, 2) Restrictions apply NMNH—Sri Lanka Agreement #6, 3) Loan from USNMNH 2065634. 4 ) Paratype; 5) Chaetocnema glabra sp. nov. des. Yongying Ruan , 2016. 2 ( BMNH), 1) West Bengal ( India) , Singur , Nhsibpur, May 1971 GBN, Oppenheimer, 2) Chaetocnema sp. C.R. Basu det., 3 ) Paratype, 4) Chaetocnema glabra sp. nov. des. Yongying Ruan, 2016.

Figures

FIGURE 88. Chaetocnema glabra sp. nov. Male habitus (hand drawing).

FIGURE 89. Chaetocnema glabra sp. nov. A Holotype (dorsal view). B Pronotum and peri-scutellar area (Holotype). C Head, frontal view (Holotype). D Aedeagus, ventral view (Holotype). E Aedeagus, lateral view (Holotype). F Apex of aedeagus, ventral view (Holotype).

FIGURE 90. Chaetocnema glabra sp. nov. A Paratype (dorsal view). B Pronotum (Paratype). C Head, frontal view (Paratype). D Vaginal palpi (Paratype). E Spermatheca (Paratype). F Pygidium (tergite 7) of female (Paratype).