Gonioctena (Gonioctena) rufa (Kraatz, 1879) revised status (Figs 1–11)

Phytodecta rufa Kraatz, 1879: 139 (type locality: Amur).

Phytodecta viminalis var. rufa: Weise 1893: 1129.

Gonioctena (Gonioctena) kamiyai Kimoto, 1963: 14, 16 (type locality: Japan, Yamanashi Pref., Masutomi), 1964: 279, 281; Medvedev & Zaitsev 1978: 120 (larva, host plant); Medvedev & Roginskaya 1988: 101 (host plant); Dubeshko & Medvedev 1989: 133 (biology); Medvedev 1992: 572 (incl. host plant); Kimoto & Takizawa 1994: 139, 229, 302; Lopatin et al. 2004: 122; Takizawa 2007: 37, 41 (incl. host plant); Cho & Lee 2008: 105, 108; Zaitsev & Medvedev 2009: 147 (larva, host plant); Kippenberg 2010: 433; Warchałowski 2010: 556; Cho & An 2020: 12. new synonym

Phytodecta (Asiphytodecta?) ussuriensis Medvedev, 1964: 180 (type locality: Russia, Primorsky Krai, Yakovlevka near Spassky).

Gonioctena (Gonioctena) ussuriensis: Medvedev 1992: 572 (as synonym of G. kamiyai).

Type material. Phytodecta rufa: Lectotype ♂ (SDEI), hereby designated: Amur, Christoph 77 // Coll. Kraatz // Syntypus // LECTOTYPUS Phytodecta rufa Kraatz, 1879 des. H.W. Cho 2013 // Gonioctena rufa (Kraatz, 1879) det. H.W. Cho 2013. Paralectotypes (2): 1 ♀ (SDEI): Amur // Syntypus // Coll. Kraatz // PARALECTOTYPUS Phytodecta rufa Kraatz, 1879 des. H.W. Cho 2013 // Gonioctena rufa (Kraatz, 1879) det. H.W. Cho 2013; 1 ♀ (SDEI): Amur // 799. // Syntypus // rufa Krtz. 1879 // Coll. Kraatz // PARALECTOTYPUS Phytodecta rufa Kraatz, 1879 des. H.W. Cho 2013 // Gonioctena rufa (Kraatz, 1879) det. H.W. Cho 2013.

Gonioctena kamiyai: Holotype and paratypes (Entomological Laboratory, Kyushu University, Fukuoka, Japan), not examined. Instead, a male specimen collected near the type locality (Yamanashi Pref.) examined.

Phytodecta ussuriensis: Paratypes (2): 1 ♀ (LMC): Primorsky Krai, 19.VI.1960, Vasiliev R. leg. // 44 // Paratypus Phytodecta ussuriensis L. Medvedev // Gonioctena ussuriensis L. Medv. det. L. Medvedev; 1 ♂ (LMC): Primorski Krai, 19.VI.1960, Kedrovaya Pad Reserv., R. Vasiliev leg. // Paratypus Phytodecta ussuriensis L. Medvedev // Gonioctena kamiyai Kim. A. Bieńkowski det. 2007.

Other material examined. JAPAN: 1 ♀ (HTC): Fukushima Pref., Tazima, Sannou toge, 10–11.VI.2004, H. Takizawa; 1 ♀ (HTC): Gunma Pref., Nakanozyo, Kawamata Onsen, 1.VI.1999, H. Takizawa; 1 ♀ (HTC): Tochigi Pref., Kuriyama, Kawamata, 5.VI.1999, H. Takizawa; 1 ♀ (SEHU): Tochigi Pref., Nakamiyori, Midorisawa-Rindo, 20.V.1989, Y. Komiya; 1 ♀ (MNHN): Japon Chuzenji [= Lake Chuzenji, Mt. Nantai, Nikko, Tochigi Pref.], 18.VII.1910, Edme Gallois; 1 ♀ (MNHN): Japon Chuzenji, 23.VII.1910, Edme Gallois; 1 ♂ (MNHN): Japon Chuzenji, 2.VIII.1911, Edme Gallois; 1 ♂ (MNHN): Mont Nantai, pres Nikko, Japon, 20.VIII.1911, Edme Gallois; 1 ♂ (HTC): Yamanashi Pref., Enzan, Hikawa Rindou, 11.V.2001, Y. Nakamura; 1 ♂ (SEHU): Yamanashi Pref., Mt. Daibosatsu, 24.VI.1979, Coll. A. Izumi. RUSSIA: 2 ♀ (NHMB): Samodon on Amur, 100 km W of Svobodny // on Corylus mandshurica // 6.VIII.1959, Zinoviev leg.; 1 ♀ (SDEI): Suyfoun, Amur, Dorries; 1 ♀ (SDEI): Chabarofka [= Khabarovsk, Khabarovsk Krai] // Weise; 1 ♀ (SDEI): Primorskiy Kray, 5 km S Ussuriysk, mixed forest, 43.40N 132.00E, 23.V.1993, leg. L. Zerche; 1 ♂ (JBC): Primorskij reg. Ussurijskij rajon, 8.VII.1975, leg. Kuznecov; 1 ♂ (BMNH): Ussuria, Preobrazenije (sinus Tasovaja), 15.VII.2002, leg. R. Filimonov; 4 ♀ (BMNH): Primorskii Krai, Lazovski Zapovednik, c. 170 km E, Vladivostok, Korpad, 3–14.V.2001, 43°16’21’’N 134°07’49’’E, 181 m, floodplain, Malaise trap 444, M. Quest coll. BMNH(E) 2009-59; 1 ♀ (SDEI): Primorskiy Kray, Vladivostok Sedanka, 100 m // 20.VI.1993, 43.09N 131.53E, leg. L. Zerche et al. SOUTH KOREA: 1 ♀ (HCC): Gangwon Prov., Chuncheon, Deokduwon, 25.IV.2001, T.W. Kim; 1 ♂ (HCC): Gangwon Prov., Pyeongchang, Mt. Gyebangsan, 20.IV.1995, K.M. Kim; 1 ♀ (HCC): Gangwon Prov., Taebaek, Cheoram, 15.V.1992, K.S. Jung; 1 ♀ (HCC): Gangwon Prov., Taebaek, Jeolgol, 5.VI.2005, T.W. Kang; 1 ♂ (HCC): Gangwon Prov., Yanggu, Nam-myeon, 26.V.1993, D.S. Ku; 3 ♀ (HCC): Gangwon Prov., Yeongwol, Gimsatgat-myeon, Nae-ri, 37°3’56.84”N, 128°45’16.72”E, 29.V.2021, H.W. Cho; 1 ♀ (HCC): Gyeongbuk Prov., Bonghwa, Seokpo-myeon, Daehyeon-ri, 28.V.1993, D.S. Ku; 1 ♀ (HCC): Gyeonggi Prov., Pocheon, Mt. Jugeum, 23.V.2004, H.C. Park; 1 ♀ (HCC): Gyeongnam Prov., Milyang, Mt. Jaeyaksan, 5.V.1992, W.J. Shin.

Diagnosis. Gonioctena rufa is a distinct species. Its coloration and aedeagal shape are unique in this genus. This species is easily distinguished from G. viminalis by its larger body size (6.9–8.2 mm versus 5.4–7.0 mm) and reddish-brown abdomen with bicolored legs (black abdomen with unicolored legs in G. viminalis).

Redescription. Measurements, in mm (n = 5): length of body: 6.90–8.20 (mean 7.62); width of body: 4.20–5.00 (mean 4.66); height of body: 2.70–3.60 (mean 3.22); width of head: 1.80–2.10 (mean 1.92); interocular distance: 1.15– 1.35 (mean 1.23); width of apex of pronotum: 2.10–2.50 (mean 2.27); width of base of pronotum: 3.30–4.02 (mean 3.64); maximum width of pronotum: 3.35–4.02 (mean 3.65); length of pronotum along midline: 1.60–1.85 (mean 1.72); length of elytra along suture: 5.30–6.35 (mean 5.87).

Body oblong oval and moderately convex (Figs 1, 3, 5). Head reddish brown, hind part black. Antennae yellowish brown, with last four antennomeres dark brown or black. Pronotum entirely reddish brown. Scutellum blackish brown. Elytra entirely reddish brown. Venter largely reddish brown, partially black. Legs reddish brown except apex of femora, apex, base and inner margin of tibiae and tarsi, black to blackish brown. Head. Vertex weakly convex, covered with dense punctures. Frontal suture V-shaped. Frons flat, strongly depressed at anterior margin, covered with dense punctures. Clypeus narrow and trapezoidal. Anterior margin of labrum distinctly concave. Mandibles with two sharp apical teeth and large excavation for apical maxillary palpomere on outer side. Maxillary palps four-segmented, with apical palpomere distinctly widened and apically truncate in male, slightly widened in female. Antennae reaching pronotal base; antennomere I robust, longest; antennomeres II–IV each subequal in length; antennomeres VII–X slightly widened, IX–X each longer than wide; antennomere XI about 1.58 times as long as wide. Pronotum. Widest at or near base, roundly and moderately narrowed anteriorly; anterior angles strongly produced. Anterior and lateral margins bordered; lateral margins visible in dorsal view. Trichobothria present on posterior angles. Disc covered with sparse punctures; lateral sides covered with much coarser and denser punctures, becoming larger toward base, partially confluent near basal margin; interspaces covered with fine and sparse punctures. Scutellum. Shape distinctly longer than wide, narrowed posteriorly. Elytra. In dorsal view moderately widened posteriorly, widest beyond middle, roundly narrowed posteriorly. Humeral calli well developed. Disc with eleven regular rows of large punctures, including a short scutellar row; interspaces covered with fine and moderately dense punctures. Epipleura wholly visible in lateral view. Hind wings fully developed. Venter. Pronotal hypomera weakly rugose, with dense punctures near anterolateral corners of prosternum. Prosternum covered with coarse and dense punctures bearing long setae; prosternal process enlarged apically, bordered laterally, with sparse punctures. Metaventrite covered with small and sparse punctures in median region, large and dense punctures in lateral region. Abdominal ventrites covered with moderately dense punctures bearing short setae; apical abdominal ventrite distinctly depressed in male. Legs. Moderately robust. Tibiae widened apically, with tooth-like projection at apex. Fore legs with tarsomere I slightly narrower than III in male; distinctly narrower than III in female. Tarsal claws appendiculate. Genitalia. Median lobe in dorsal view rather thick, with median process enlarged and divided into two processes at apex, lateral processes shorter than median process (Fig. 8); median lobe in lateral view strongly sinuate, with long processes (Fig. 9). Japanese population with more curved median process and shorter lateral processes of aedeagus (Fig. 11) than Russian and Korean populations (Figs 9–10). Spermatheca absent.

Distribution. South Korea, Japan (Honshu), Russia (Primorsky Krai, Khabarovsk Krai, Amur Oblast) (Fig. 7).

Host plants. Betulaceae: Betula, Corylus; Salicaceae: Salix.

Remarks. Kraatz (1879) described Gonioctena rufa from Amur based on its large body, reddish-brown ground color, and bicolored legs, comparing it with G. viminalis. However, Weise (1893) treated G. rufa as a variety of G. viminalis, and Bechyně (1948) deemed it a subspecies of G. viminalis, which has since been accepted by many authors (for example, Medvedev 1992; Lopatin et al. 2004; Kippenberg 2010). I examined the type specimens of G. rufa in the Senckenberg German Entomological Institute collection (Figs. 1, 2) and found that it is a distinct species based on its body size and coloration, as previously mentioned by Kraatz (1879). Indeed, two lateral processes of the male genitalia (Figs. 8, 9) are a remarkable, unique feature within the genus Gonioctena. Specimens of G. viminalis with reddish-brown legs in northeast Asia have been misidentified as G. viminalis rufa since Bechyně (1948), who did not examine the type material. Therefore, G. rufa is removed from the status of a subspecies of G. viminalis, and its species status is restored. The male syntype is here designated lectotype, to fix the identity of this species.

Several Palaearctic species of Gonioctena show regional differences in the shape of the male genitalia (Cho et al. 2016). Despite the shorter lateral processes of the aedeagus, I conclude that G. kamiyai Kimoto, 1963 and its synonym G. ussuriensis (Medvedev, 1964) should be synonymized with G. rufa (Figs. 3–5).

When dissecting specimens, many larvae were found in the abdomens of two females collected in Taebaek and Nakamiyori (Fig. 6). Ovoviviparity is a common mode of reproduction in the subgenus Gonioctena (Cho 2019), and G. rufa is newly reported as an ovoviviparous species.