Gonioctena (Brachyphytodecta) liui, Lee & Hsieh, 2022

Lee, Chi-Feng & Hsieh, Chia-Hung, 2022, Integrative taxonomy of the leaf-beetle genus Gonioctena Chevrolat, 1836 in Taiwan (Coleoptera, Chrysomelidae, Chrysomelinae, Gonioctenini) reveals new synonymies and one new species, ZooKeys 1120, pp. 1-46 : 1

Gonioctena (Brachyphytodecta) liui sp. nov.

Figs 9D-F , 12 , 13

Gonioctena issikii : Ge et al. 2007: 582 (aedeagus); Cho 2016: 95 (redescription). Misidentification

Types (n = 95).

Holotype ♂ (TARI): TAIWAN. Nantou: Peitungyanshan (北東眼山), 3.VII.2014, leg. F.-S. Huang, 變葉新木薑子 ( Neolitsea aciculata var. variabillima ) 噴霧 (fogging). Paratypes. Nantou: 3♂, 4♀ (TARI), Lienhuachih (蓮華池), 7.V.2016, leg. C.-J. Liu; 5♂ (TARI), same but with “21.V.2016”, reared from larvae; 5♂, 5♀ (TARI), same locality, 10.V.2016, leg. H. Lee; 9♂, 9♀ (TARI), same but with “20.V.2017”; 5♂, 1♀ (TARI), same locality, 12.V.2016, leg. P.-H. Li; 2♀ (TARI), same locality, 22.III.2018, leg. J.-C. Chen; 3♂, 1♀ (TARI), same locality, 25.V.2019, leg. B.-H. Ho; 9♂, 15♀ (TARI), same locality, 20.IV.2020, leg. C.-F. Lee; 12♂, 7♀ (TARI), same but with “3.VI.2020”; 1♂, 3♀ (TARI), same locality, 16.IV.2021, leg. W.-C. Liao.

Description.

Length 5.3-6.1 mm, width 3.2-3.9 mm. Body color (Fig. 9D-F ) blackish brown; antennomeres I-V, sides of pronotum and hypomeron yellowish brown; elytra with wide yellowish brown outer margins and suture. Antennae (Fig. 12A ) with antennomere III slender, IV and V slightly swollen, VI and VII moderately swollen, VIII-X strongly swollen, XI elongate oval, length ratios of antennomeres I-XI 1.0: 0.5: 0.6: 0.5: 0.4: 0.4: 0.5: 0.6: 0.6: 0.6: 1.0, length to width ratios of antennomeres I-XI 2.1: 1.5: 2.2: 1.6: 1.5: 1.0: 1.0: 1.0: 1.1: 1.0: 1.8. Pronotum 2.3 × wider than long, lateral margins widest at base, convergent anteriorly, anterior angles strongly produced; anterior and lateral margins bordered, lateral margins barely visible in dorsal view; trichobothria absent on both anterior and posterior angles; disc covered with sparse fine punctures and mixed with finer punctures; both sides covered with much larger, denser punctures. Scutellum distinctly wider than long, narrowed posteriorly. Elytra 1.3 × longer than wide; lateral margins slightly wider posteriorly, widest near middle; humeral calli well developed; disc covered with rather regular coarse punctures arranged into single stria; interspaces covered with fine, sparse punctures. Hind wing well developed. Aedeagus (Fig. 12B . C) with apical process wide and short in dorsal view, 0.1 × as long as aedeagus; lateral margins slightly narrowed in basal 1/3; strongly curved in lateral view; endophallic sclerite extremely elongate. Gonocoxae (Fig. 12D ) narrow, but apically narrowed, with few long setae along apical margins. Ventrite VIII (Fig. 12E ) transverse, with several long setae along outer margin. Receptacle of spermatheca (Fig. 12F ) slightly swollen, not separated from pump; pump short and curved; sclerotized proximal spermathecal duct moderately short.

Diagnosis.

Gonioctena (Brachyphytodecta) liui sp. nov. can be distinguished from the other consubgeneric species, G. (B.) scutellaris , by the following combination of the characters: black head, most of pronotum (Fig. 9D ), and thoracic and abdominal ventrites (Fig. 9E ) (yellowish brown head and pronotum (Figs 8A , 9A ), thoracic and abdominal ventrites (Figs 8B , 9B ) in G. (B.) scutellaris ), short, wide apical process of aedeagus (Fig. 12B, C ) (extremely elongate apical process of aedeagus in G. (B.) scutellaris (Fig. 10B, C ), and narrow gonocoxae covered with fewer setae (wide gonocoxae covered with more setae in G. (B.) scutellaris ).

Although Ge et al. (2007) drew only the aedeagi in dorsal and lateral views when G. issikii was mentioned, it is easily identified as this new species. Cho (2016) redescibed G. issikii in detail but it actually fits perfectly this new species. The type specimen was not studied by these authors mentioned above.

Host plant.

Fabaceae : Ormosia formosana Kanehira (new record, present study).

Biology.

Gonioctena (Brachyphytodecta) liui populations are presumed to be multivoltine during spring, and females are ovoviviparous. Host plants are one of only a few woody Fabaceae in Taiwan. They grow 7-9 m high (Fig. 13A ). They started blooming during April (Fig. 13B ). Most adults (Fig. 13F ) and larvae were collected from flower buds (Fig. 13C ). Females deposited larvae and the larvae (Fig. 13D ) fed on internal tissues of the flower buds through holes chewed by adults. They preferred to feed on the flower buds rather than young sprouts. The larval duration was eight days. Mature larvae (Fig. 13D ) burrowed into the soil and built underground chambers for pupation. The duration of the pupal stage (Fig. 13E ) was nine days at room temperature. Flowering season of the host plant occurs from April to June ( Huang and Ohashi 1993), but the blooming period for individual trees is less than a month.

Remarks.

The host plant is an endemic and rare species in Taiwan that is restricted to the central regions ( Huang and Ohashi 1993). Few insects utilize it as a foodplant. The only species documented until now is a skipper, Hasora anura taiwana Hsu et al. 2005 ( Lepidoptera ), which is monophagous on Ormosia formosana Kanehira as a larval foodplant ( Hsu et al. 2005).

Entomology.

The species name is dedicated to Mr. Cheng-Jr Liu (呂晟智) who collected types and discovered the host plant.

Distribution.

This new species is restricted to Central Taiwan.

Figures

Figure 8. Habitus of Gonioctena (Brachyphytodecta) scutellaris Baly and G. (B.) fulva (Motschulsky) A G. (B.) scutellaris, typical form, dorsal view B ditto, ventral view C same species, color variation, syntype of G. dichroa Fairmaire D G. (B.) fulva, dorsal view E ditto, ventral view F ditto, lateral view.

Figure 9. Habitus of Gonioctena (Brachyphytodecta) scutellaris Baly and G. (B.) liui sp. nov. A G. (B.) scutellaris, color variation, from Taiwan, dorsal view B ditto, ventral view C ditto, lateral view D G. (B.) liui sp. nov., dorsal view E ditto, ventral view F ditto, lateral view.

Figure 10. Diagnostic characters of Gonioctena (Brachyphytodecta) scutellaris Baly A antenna B aedeagus, dorsal view C aedeagus, lateral view D gonocoxae E abdominal ventrite VIII F spermatheca.

Figure 12. Diagnostic characters of Gonioctena (Brachyphytodecta) liui sp. nov. A antenna B aedeagus, dorsal view C aedeagus, lateral view D gonocoxae E abdominal ventrite VIII F spermatheca.

Figure 13. Natural history of Gonioctena (Brachyphytodecta) liui sp. nov. on host plant Ormosia formosana (Fabaceae) A the whole tree, Ormosia formosana (Fabaceae), the shape indicated by arrows B bloomed in April C flower buds and larvae collected with the sweeping net D fourth-instar larva burrowing into the soil and built underground chambers for pupation E pupa F adults.