The genus LiliocerisReitter, 1912 is the second largest genus of the subfamily Criocerinae, with approximately 150 species described to date (Monrós, 1960;Heinze and Pinsdorf, 1962;Gressitt, 1965;Warchałowski, 2011;Bezděk and Schmitt, 2017;Xu and Liang, 2022). This genus is widely distributed in tropical and subtropical regions of the world, with the highest species diversity found in the Oriental Region (Xu and Liang, 2022). In the Palaearctic Region, 40 species are known (Lopatin, 1977;Park et al., 2012). Several species have also been reported from South Korea; however, some of these records are have been misidentified, and taxonomic re-evaluation is required (Lee and An, 2001;An and Kim, 2020;Cho and An, 2020;KSAE and ESK, 2021).

Larvae of Lilioceris are characterized by distinct dorsal tubercles, with at least small obscure tubercles on the mesoand metathorax, or by two rows of dorsal setae on each of these thoracic segments (Park et al., 2012). This genus typically inhabits forest margins and farmland habitats, and all developmental stages are closely associated with host plants, primarily within the order Liliales, including Dioscoreaceae, Smilacaceae, and Liliaceae (Xu and Liang, 2022). Larvae employ defensive strategies against predators by carrying fecal matter on their dorsum and discharging fluids through the oral cavity (Cho and Lee, 2005;Park et al., 2012).

In this study, we provide descriptions and illustrations of the larvae, COI gene sequences, adult habitus photographs, and illustrations of the genitalia. In addition, a taxonomic key for adult species of the genus Lilioceris is provided.

Materials and Methods

Adults were collected in May 2025 from Seodaesin-dong 3-ga, Seo-gu, Busan, Republic of Korea (35° 7'29.51"N, 129° 0'28.21"E). After hatching, larvae were reared in plastic containers (20 cm wide, 15 cm long, and 8 cm deep) provided with the host plant, Smilax china Linnaeus, and observed daily. Specimens used in this study were preserved in 70% ethanol. For the morphological analysis, the specimens were cleared in a 10% KOH solution for 30 minutes and subsequently rinsed with water. Dissections were performed under a stereoscopic microscope (Nikon SMZ 745T). For a detailed morphological analysis of minute structures, slides were prepared for various body parts and observed under a compound microscope (Leica DM 2500). Habitus images were captured using a Canon EOS 5D Mark 5D IV digital camera attached to a Canon EF 100mm F2.8 Macro USM. The morphological terminology was based primarily on Anderson (1947) and Kimoto (1962).

DNA Sequencing and Molecular Analysis

Genomic DNA was extracted from the legs of the three specimens using the LaboPas Tissue Genomic DNA Isolation Kit Mini (Cosmo Genetech Inc., Seoul, Korea), according to the manufacturer’s instructions. The COI barcode fragment was amplified using a universal primer pair (LCO1490 and HCO2198) under the following cycling conditions: 2 min at 94°C; followed by 35 cycles of 98°C for 15 s, 53°C for 30 s, and 68°C for 60 s; and a final extension at 68°C for 5 min. Subsequently, the amplified products were sequenced using an ABI 3100 automated sequencer (Perkin-Elmer, CA, USA).

COI sequences amplified from the three Lilioceris subpolita were aligned with the COI sequences of five other Lilioceris species retrieved from the National Center for Biotechnology Information (NCBI) database (Table 1). Sequence assembly, alignment, and trimming were performed using the Geneious 8.1.9 software (Kearse et al., 2012). Pairwise genetic distances were calculated using the Kimura 2-parameter (K2P) substitution model in MEGA X v12.0.11 (Kumar et al., 2018).

Systematic Accounts

Family Chrysomelidae Latreille, 1802

Subfamily Criocerinae Latreille, 1804

Genus LiliocerisReitter, 1912

Diagnosis (Fig. 1A-D). Body length 7.3–11.5 mm, width 4.0–4.5mm, elongate and moderately convex; head, antenna and scutellum black, pronotum and elytra red; mesoepisternum, mesoepimeron, metaepisternum, lateral sides of mesoventral, lateral sides of sternite, and entirely legs black, remainders red (Xu et al., 2021).

Descriptions

Last instar larva (Fig. 2C;3A-I). Body length 9.5 ± 1.7 mm, width 4.9 ± 0.3 mm, head width 1.4 ± 0.1 mm (n=5).

Body slightly convex, The body color of mature larvae is orange, while immature larvae are dark yellow, covered with a slimy mucous secretion usually bearing excrement. Head, pronotum and legs black. Body covered with both large and small tubercles.

Head (Fig. 3D). Hypognathous, rounded, well sclerotized, epicranial suture Y-shaped; frontal suture distinct. Stemmata well developed, six in number. Endocarina very short; frons with 3 pairs of frontal setae. Clypeus (Fig. 3I) trapezoid, with 2 pairs of setae and 1 pair of sensilla; labrum notched on anterior margin, with 3 pairs setae and 1 pair of sensilla. Epipharynx with 10 pairs of setae. Antenna (Fig. 3G) 2-segmetned, segment 1 with 4 sensilla at anteriorly, segment 2 with a conical sensilla papilla, 8 sensilla basiconium. Mandible (Fig. 3C) with 3 distal teeth and 1 mandibular seta. Maxillary palp three-segmented; palpifer with 2 setae, numerous short setae and 1 sensilla; stipes with 1 seta; cardo with 2 setae (Fig. 3H). Lacinia fused with stipes; galea with 9 setae; Labial palp (Fig. 3H) 1 segmented; prementum with 2 pairs of setae and 4 pairs of sensilla; postmentum with 2 pairs of setae.

Thorax. Pronotum (Fig. 3E) sclerotized, with 18 pairs of setae. Thoracic spiracles (Fig. 3B) biforous; Legs short and slender; tibia (Fig. 3F) with 5 setae; tarsus strongly curved, hook-like; pulvillus present.

Abdomen. Abdominal spiracles present on segments I-VIII similar to prothoracic spiracles but smaller. Anal opening present on abdominal segment IX.

Host plant. Smilax china Linnaeus

Distribution. Korea (new record), Japan, Russia

Remarks. The South Korean fauna of the genus Lilioceris has been subject to ongoing taxonomic revision, and as a result six species—L. gibba, L. merdigera, L. rugata, L. scapularis, L. sinica, and L. sieversi—have been recorded (Lee and An, 2001;An and Kim, 2020;Cho and An, 2020;KSAE and ESK, 2021). However, incorrect species identifications have led to continued dissemination of erroneous information. In particular, the taxonomic identities of L. rugata and L. sinica have been questioned (Cho and An, 2020;Xu and Liang, 2022). Examination of specimens identified as L. rugata and L. sinica revealed that all of them are in fact, L. theana. Furthermore, L. gibba was actually Mecoprosopus minor Pic, 1916. Because only a single specimen is known, its presence in Korea remains unclear (Table 2).

Molecular Data

We obtained a 609 bp fragment sequence of the COI gene from three individuals of L. subpolita, and deposited in Gen- Bank under accession numbers PX884512- PX884514. Genetic distance analysis based on a 606 bp fragment of the COI gene showed that intraspecific divergence among Lilioceris species ranged from 0.0% to 6.8%, with L. subpolita exhibiting no genetic variation (0.0%). The interspecific genetic distances within the genus Lilioceris ranged from 9.1% to 22.0%, and the genetic distances between L. subpolita and other species ranged from 18.1% to 22.0% (Table 3).

Key to the Adults of South Korean Lilioceris Species