Gonioctena (Gonioctena) lukasi, Cho, 2022

Cho, Hee-Wook, 2022, Two new species of the nominotypical subgenus Gonioctena Chevrolat, 1836, from China and Laos, and a proposed new species-group (Coleoptera: Chrysomelidae: Chrysomelinae), Zootaxa 5150 (1), pp. 111-120 : 114-116

Gonioctena (Gonioctena) lukasi new species

( Figs 3–4 , 8 , 12 )

Type locality. China: Zhejiang Province, Tianmu Mountain .

Type material. Holotype: ♂ ( SNUC), “ CHINA: ZHEJIANG Prov., West Tianmu Shan (Mts) reserve mixed forest nr Chayuan temple 30°19.5–7’N, 119°26.5’E, 400–465 m, 23.vi.–4.vii. 2017 J. Hájek & J. Růžička leg. // HOLOTYPUS Gonioctena lukasi sp. nov. des H.W. Cho 2021” . Paratypes: 6 ♂♂, 4 ♀♀ ( SNUC) , 6 ♂♂, 2 ♀♀ ( NMPC) , same data as holotype plus “ PARATYPUS Gonioctena lukasi sp. nov. des H.W. Cho 2021” ; 1 ♀ ( NMPC) , “ CHINA: ZHEJIANG Prov., West Tianmu Shan (Mts) reserve, Immortal Peak ; mountainous low forest, esp. on flowering Castanea seguinii , 5.–6.vii.2017; 1500 m 30°20’58.5”N, 119°25’26.5”E, J. Hájek & J. Růžička leg. // PARATYPUS Gonioctena lukasi sp. nov. des H.W. Cho 2021” .

Diagnosis. This new species is similar to Gonioctena kanfani , in that the pronotum lacks spots and the elytral punctures are arranged in almost regular single rows. However, G. lukasi new species can be distinguished by the median lobe which is strongly medially constricted in dorsal view and greatly expanded in lateral view (long and thin in G. kanfani ).

Description. Measurements in mm (n = 5): Length of body: 6.40–8.30 (mean 7.46); width of body: 3.65–4.77 (mean 4.26); height of body: 2.30–3.07 (mean 2.73); width of head: 1.86–2.16 (mean 2.01); interocular distance: 1.26–1.47 (mean 1.36); width of apex of pronotum: 2.12–2.57 (mean 2.35); width of base of pronotum: 3.12–3.83 (mean 3.53); maximum width of pronotum: 3.20–3.92 (mean 3.58); length of pronotum along midline: 1.54–1.83 (mean 1.71); length of elytra along suture: 4.68–6.10 (mean 5.44).

Body oblong-ovate and moderately convex ( Figs 3, 4 ). Head and pronotum dark reddish-brown to greenishblack with dull metallic lustre. Mouthparts dark reddish-brown with apices of mandibles black. Antennomeres I–V reddish-brown; VI–VII darkened; VIII–XI black. Elytra greenish-black with bright metallic lustre; humeri each with black spot surrounded by yellowish-brown circle. Venter and legs dark reddish-brown, partially darkened. Head. Vertex weakly convex, with moderately dense punctures, becoming denser toward sides. Frontal suture V-shaped, coronal suture weak. Frons flat, strongly depressed at anterior margin, covered with dense punctures. Clypeus rather narrow and trapezoidal.Anterior margin of labrum weakly concave. Mandibles with two sharp apical teeth and deep lateral excavations for maxillary palpomeres. Maxillary palpi four-segmented with apical palpomeres moderately widened, truncate apically. Antennae almost reaching pronotal base; antennomere I robust and longest; II longer than III; III longer than IV; VI–X widened; XI about 1.33 times as long as wide. Pronotum. In dorsal view widest near base, moderately convexly narrowed anteriorly, anterior angles strongly produced. Anterior and lateral margins bordered; lateral margins usually distinct in dorsal view. Trichobothria absent from anterior angles, present on posterior angles. Disc with sparse to dense punctures; lateral sides with much larger and denser punctures, partially confluent; interspaces with fine and moderately dense punctures. Scutellum . Slightly wider than long, narrowed posteriorly. Elytra. In dorsal view moderately widened posteriorly, widest beyond middle, roundly narrowed posteriorly. Humeral calli well developed. Disc with 11 almost regular rows of large punctures, including short scutellar row, with few strial punctures out of alignment; interspaces with fine and sparse punctures. Epipleura mostly visible (except apical 2/5) in lateral view. Hind wings well developed. Venter. Pronotal hypomera weakly rugose with coarse punctures on anterior 1/5. Prosternum with coarse and dense punctures bearing long setae; prosternal process enlarged apically, bordered laterally, with sparse punctures. Metaventrite with minute and sparse punctures medially, large and dense punctures laterally. Abdominal ventrites with sparse to dense punctures bearing short setae; apex of last visible abdominal ventrite distinctly depressed in male. Legs. Moderately robust. Tibiae widened apically with tooth-like projections. Forelegs with tarsomere I slightly narrower than III in male; distinctly narrower than III in female. Tarsal claws appendiculate. Genitalia. Median lobe in dorsal view strongly medially constricted and with thin apical lobe ( Fig. 8 ); in lateral view apical 1/2 greatly enlarged with apical process curved and tapered; distal tip of flagellum trifurcated. Spermatheca absent.

Etymology. The species is dedicated to my colleague Dr. Lukáš Sekerka (National Museum, Czech Republic), who kindly sent me the material for investigation.

Distribution. China: Zhejiang ( Fig. 12 ).

Figures

FIGURE 12. Distribution map of the Gonioctena kanfani species-group based on the specimens examined and literature records.

FIGURES 3–4. Gonioctena lukasi new species, male holotype. 3: dorsal habitus, 4: lateral habitus. Scale bar: 1.0 mm.

FIGURES 7–11. Gonioctena species, male genitalia. 7: G. jolantae new species (dorsal, apico-dorsal & lateral), 8: G. lukasi new species (dorsal & lateral), 9: G. kanfani (Chen, 1941) (apico-dorsal & lateral, redrawn from Yang et al. 2014), 10: G. kamikawai (Chûjô, 1958) (dorsal, apico-dorsal & lateral), 11: G. fujiana Cho & Borowiec, 2016 (dorsal, apico-dorsal & lateral). Scale bars: 1.0 mm.