The subfamily Donaciinae, commonly called reed beetles, is an ecologically well-defined group of the family Chrysomelidae with its aquatic habitats. The adults live on leaves of aquatic host plants and the larvae feed on submerged roots. Approximately 170 species in seven genera are mainly distributed in temperate regions of the Holarctic, Africa and Australia (Leschen and Konstantinov, 2014). In the Korean Peninsula, eight species of Donacia and three species of Plateumaris have been previously recorded (Cho and An, 2020). Sominella macrocnemia (Fischer von Waldheim, 1824) was described from Dauria, and since then it has been reported from Russia, Mongolia, and China (Hayashi, 2012). Warchałowski (2010) added this species to the Korean fauna without specimen data, so it was considered doubtful.

During the examination of material deposited in the Museum of Natural History, University of Wrocław, Poland, the first author found a single specimen of S. macrocnemia collected in North Korea. It was obtained during the 1974 expedition to North Korea by the Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Kraków, Poland (Pawłowski and Tomek, 1997). Probably based on this material, Warchałowski (2010) listed S. macrocnemia from Korea. In the present study, we confirm the occurrence of S. macrocnemia from North Korea for the first time by the examination of the specimen. Habitus photographs and diagnostic characters are also provided.

Materials and Methods

The specimen was examined with a Leica S8 APO microscope. The photographs were taken using a Nikon D850 digital camera attached to a Leica M165C microscope, and then combined using Helicon Focus image stacking software. A double slash (//) in the collecting data separates the data on different labels. The material examined is deposited in the collection of the Museum of Natural History, University of Wrocław, Wrocław, Poland.

Taxonomic Accounts

Family Chrysomelidae Latreille, 1802 잎벌레과 Subfamily Donaciinae Kirby, 1837 뿌리잎벌레아과

Genus Sominella Jacobson 긴다리뿌리잎벌레속

SominellaJacobson, 1908: 622 (type species: Donacia macrocnemiaFischer von Waldheirn, 1824).

Diagnosis. Members of Sominella generally share the following features: antennomere III as long as or longer than IV; elytra sparsely and coarsely rugose, with interspaces finely punctulate. Other characters such as density and coarseness of pronotal punctation, hypomeral pubescence, shape of elytral apex, and metatibial tooth are various (Askevold, 1990).

Sominella macrocnemia (Fischer von Waldheim, 1824) 긴 다리뿌리잎벌레 (Fig. 1A~D)

Donacia macrocnemiaFischer von Waldheirn, 1824: 235.

Plateumaris excisipennisJacobson, 1894: 243.

Sominella macrocnemia: Jacobson, 1908: 623.

Diagnosis (Fig. 1A-B). This species is similar to S. longicornis Jacoby, 1890 in having elongate hind legs and femur and tibia with a prominent tooth on apical-ventral side in male. However, S. macrocnemia can be distinguished by the following characters: pronotum irregularly rugose-punctate on disc (large part transversely vermiculate-corrugate in S. longicornis); elytral interspaces with transverse microcorrugations (without corrugations in S. longicornis); elytral apex emarginate, inner apical angle prominent (truncate in S. longicornis).

Material examined. 1 ♀, “Korea 13.6.1974, Thesong Lacus [= Taesongho Lake, Ryonggang, South Pyongan Province, North Korea], Exp. Inst. Zool. Cr. // Sominella macrocnemia” (Fig. 1C).

Distribution. Russia (East Siberia, Far East), Mongolia, China (Heilongjiang, Hubei, Jilin, Liaoning, Shandong), North Korea (first confirmation, Fig. 1D).

Remarks. The occurrence of Sominella macrocnemia from the Korean Peninsula is confirmed based on the examination of the specimen. In recent years, records of the genus in the eastern Palearctic Region have been confirmed for S. longicornis in south China and Laos (Hayashi, 2012), but there is no additional collecting data for S. macrocnemia from Russian Far East, northeast China and the adjacent regions in the last half-century. The natural history, morphology of immature stages, and host plants of S. macrocnemia remain unknown.