Two new species of the Gonioctena (Asiphytodecta) subgeminata species group from Vietnam (Coleoptera: Chrysomelidae)

Cho Hee-Wook
Acta Entomologica Musei Nationalis Pragae 66(1): 123-128, 2026
Published online: 4th August 2026
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Abstract: Two new species of the Gonioctena (Asiphytodecta) subgeminata species group, Gonioctena acutangula sp. nov. and G. dakgleiensis sp. nov., are described from Vietnam. The species group was previously known to comprise five species distributed in China and Vietnam and is characterized by elytra with spots or sinuate transverse bands, elytral punctures arranged in regular single rows or in confused rows, and aedeagus with a broad apical process bearing apicolateral setae. Gonioctena acutangula sp. nov. is externally similar to G. tonkinensis (Chen, 1934) but differs in the structure of the aedeagus, particularly in the apical portion strongly produced dorsally in lateral view. Gonioctena dakgleiensis sp. nov. is similar to G. subgeminata (Chen, 1934) but differs in the elytral pattern, lacking two large black spots straddling the elytral suture and possessing a distinct median dark patch. DNA barcode sequences of the mitochondrial COI gene are provided and deposited in GenBank. Photographs of the habitus, illustrations of the aedeagi, and a key to the species of the group are provided.
Key words: Coleoptera, Chrysomelidae, Gonioctena, Asiphytodecta, DNA barcoding, new species, Vietnam, Oriental Region