Chaetocnema (Chaetocnema) dapitanica 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 : 41-43

7. Chaetocnema (Chaetocnema) dapitanica Ruan, Konstantinov & Yang , New Species

( Fig. 26 )

Etymology: This species is named after the type locality ‘Dapitan’. Specific epithet is a noun in apposition.

Diagnosis: This species is close to C. sabahensis sp. nov. and C. hainanensis in the shape of aedeagus and spermatheca. It can be differentiated from the latter two species by the difference in body shape, larger body size and weaker punctation on pronotum. It also resembles C. trapezoida sp. nov. by the more or less trapezoidal pronotum, however, they differ in body size, shape and color.

Distribution: Philippines.

Host plants: Unknown.

Description: Body Length 2.35–2.50 mm, body width 1.40–1.50. Ratio of elytron length (along suture) to width (maximum): 2.50–2.60. Ratio of pronotum width (at base) to length: 1.70–1.75. Ratio of length of elytron to length of pronotum (along middle): 2.60–2.70. Ratio of width of elytra at base to width of pronotum at base (in middle of humeral calli): 1.25–1.35. Ratio of maximum width of elytra to maximum width of pronotum: 1.40–1.50.

Dorsum deep brown, with very slight bronzy luster. Pronotum black with obscure bronzy metallic luster. All antennomeres yellow brown. Tibiae pro- and mesofemora yellow. Metafemora dark brown.

Head hypognathous. Frontal ridge narrow, convex. Frontolateral sulcus present. Suprafrontal sulcus shallow and faint. Suprafrontal sulcus straight to shallowly retuse. Ratio of width of frontal ridge to width of antennal socket: 1.14–1.15. Frons with long setae on sides. Vertex flat, situated on same level as orbit, with 4–7 punctures near each eye, punctures rugged.

Base of pronotum without short longitudinal impressions or transverse antebasal impression. Deep row of large punctures at base of pronotum absent. Pronotum somewhat trapezoidal, pronotal base distinctly expanded in middle, forming a lobe. Lateral margins of pronotum nearly straight, converging anteriorly. Anterolateral prothoracic callosity obtuse, weak, protruding laterally. Posterolateral prothoracic callosity poorly developed. Pronotal punctures extremely weak, diameter of pronotal punctures 6 to 10 times smaller than distance between them.

Elytra with convex sides. Scutellar row of punctures on elytron regular and single. Second to eleventh rows of punctures regular. Interspaces between puncture rows costate and smooth, with 3–4 rows of minute punctures. Base of elytra obviously impunctate. Humeral calli well developed.

First and second male protarsomeres, length to length ratio: 1.40–1.50. First male protarsomere, length to width ratio: 1.30–1.50. Excavation on metatibia moderately developed. Large lateral denticle on metatibia sharp. Metatibial serration proximal to large lateral denticle absent. Metatibia proximad to denticle in dorsal view convex.

Apex of aedeagus in ventral view narrowing abruptly. Ventral longitudinal groove slightly developed or absent. Apical denticle of aedeagus in ventral view well formed, with narrowly rounded apex. Apical denticle of aedeagus in lateral view strongly curved dorsally. Minute transverse wrinkles on ventral side of aedeagus absent. Aedeagus in lateral view sinusoidal near apex. Maximum curvature of aedeagus in lateral view situated apically.

Spermathecal pump much shorter than receptacle. Apex of spermathecal pump cylindrical. Spermathecal receptacle pear-shaped. Maximum width of receptacle situated basally. Receptacle basally wider than apically. Apex of vaginal palpus subtriangular, with lateral margin slightly convex. Vaginal palpus (before apex) narrowing from base till middle, thence slightly widening towards apex. Anterior sclerotization of vaginal palpus sinusoidal. Anterior end of anterior sclerotization broadly rounded. Posterior sclerotization longer than wide. Posterior sclerotization wider than anterior. Last visible abdominal tergite of female without punctures.

Types: Holotype: ♂ ( USNM), labels: 1) Dapitan, Mindanao, leg. Baker, 1927, C. F. Baker collection; 2) Loan from USNMNH 2065634; 3) Chaetocnema dapitanica sp. nov. Des. Ruan et al., 2016.

Paratypes: 4♂ 8♀ ( USNM), labels: 1) Philippines, Dapitan, Mindanao, leg. Baker, 1927, C. F. Baker collection; 2) Loan from USNMNH 2065634; 3) Chaetocnema dapitanica sp. nov. Des. Ruan et al., 2016 . 2♀ ( USNM), labels: 1) Philippines, Mt. Makiling , Luzon, Baker; 2) Loan from USNMNH 2065634; 3) Chaetocnema dapitanica sp. nov. Des. Ruan et al., 2016 .

Figures

FIGURE 26. Chaetocnema dapitanica sp. nov. A Male habitus (Holotype). B Pronotum (Holotype). C Head, frontal view (Holotype). D Aedeagus, ventral view (Paratype). E Aedeagus, lateral view (Paratype). F Apex of aedeagus, ventral view (Paratype). G Vaginal palpi (Paratype). H Spermatheca (Paratype). I Pygidium (tergite 7) of female (Paratype).