Revision of the Gonioctena nivosa species-group (Coleoptera, Chrysomelidae, Chrysomelinae) in the Holarctic region, with descriptions of two new species

Abstract The Gonioctena nivosa species-group of the genus Gonioctena Chevrolat, 1836 is defined and reviewed. It contains six species including two new to science: Gonioctena gracilicornis (Kraatz, 1879), Gonioctena nivosa (Suffrian, 1851), Gonioctena norvegica (Strand, 1936), Gonioctena springlovae (Bechyně, 1948), Gonioctena amurensis Cho & Borowiec, sp. n. and Gonioctena jani Cho & Borowiec, sp. n. Six new synonyms are proposed: Gonioctena nivosa (= Gonioctena arctica alberta Brown, 1952, syn. n., Phytodecta linnaeana bergrothi Jacobson, 1901, syn. n., Phytodecta linnaeanus var. mutatus Achard, 1924, syn. n., Phytodecta linnaeanus var. simplex Achard, 1924, syn. n. and Phytodecta nivosa var. cedehensis Ronchetti, 1922, syn. n.) and Gonioctena norvegica (= Gonioctena janovskii Medvedev, 1976, syn. n.). Phytodecta flavicornis var. limbatipennis Achard, 1924 and Phytodecta nivosa var. bicolor Heyden, 1883 are removed from synonymy with Gonioctena nivosa (Suffrian, 1851) and are synonymized with Gonioctena flavicornis (Suffrian, 1851). Distribution maps, a key to species, color variation, geographic variation of male genitalia and host plants are provided. Ovoviviparity is newly recorded in Gonioctena gracilicornis and Gonioctena nivosa. Lectotypes are designated for Gonioctena affinis, Gonioctena arctica, Gonioctena linnaeana bergrothi and Gonioctena nivosa.


Introduction
The genus Gonioctena Chevrolat, 1836 with about 100 described species in nine subgenera is one of the largest genera within the subfamily Chrysomelinae (Cho and Borowiec 2016). The nominotypical subgenus is the largest and contains 47 species that are widely distributed in the Holarctic and Oriental regions (Cho 2016). Many species of the nominotypical subgenus have received much attention due to their extremely high variability in coloration. Although the color pattern of several species has been revealed (Bechyně 1948, Silfverberg 1994b, V. L. Medvedev 2003, a similar color pattern between closely related sympatric species has produced a number of synonyms and misidentifications. The structure of male genitalia is generally used as the only source of reliable diagnostic characters. However, the shape of aedeagus is often geographically variable in several species with wide distributions or it is very similar between closely related species. The taxonomic status of these forms is still unclear. Kippenberg (2010) mentioned that 13 species of the subgenus Gonioctena s. str. in the catalogue of Palaearctic Coleoptera are characterized by the external morphology because they often have the similar shape of aedeagus. For example, the taxonomic status of the following taxa has been interpreted controversially: G. arctica Mannerheim, 1853 from Alaska, G. decaspilota (Achard, 1924) from the Scandinavian Peninsula, G. dinah (Bechyně, 1948) from Siberia, G. nivosa (Suffrian, 1851) from the Alps and G. salicis Motschulsky, 1860 from Transbaikalia.
In the present study, we define and review the Gonioctena nivosa species-group of the subgenus Gonioctena s. str. Six species including two new species are recognized by the following characters: apical antennomere more than twice longer than wide; first tarsomere of fore legs in male swollen; apical process of aedeagus narrow, with apex rather truncate in dorsal view, apical process pointed and slightly bent downward at apex in lateral view. We have attempted to solve its taxonomic problems based on the external morphology, geographic variation of male genitalia, coloration and distribution. Biological information on host plant and ovoviviparity is also provided.

Material and methods
Specimens were examined with a Nikon SMZ800 microscope. Male genitalia were dissected from adult specimens softened in the closed Petri dish with wet tissue paper for 12-24 hours, cleared in 10% sodium hydroxide solution, and rinsed in distilled water. Photographs were taken by a Nikon D5200 digital camera attached to a Nikon SMZ1500 microscope, and were edited by Helicon Focus 5.3.12 and Adobe Photoshop CS5. A double slash (//) in the collecting data separates the data on different labels. Type localities are cited in the original spelling. Specimens examined in the study are deposited in the following collections: Diagnosis. Gonioctena amurensis sp. n. is closely related to G. jani sp. n. in having small body size and similar length of antennae, however it can be distinguished by pronotum with small and moderately dense punctures on median region and large and dense punctures on lateral region (sparse punctures on median region and moderately dense punctures on lateral region in G. jani sp. n.) and rather thin aedeagus with relatively long apical process (rather thick with relatively short apical process in G. jani sp. n.).
Head. Vertex weakly convex, covered with coarse and dense punctures. Frontal suture V-shaped, coronal suture absent or weak. Frons flat, strongly depressed anteriorly, covered with moderately dense punctures. Clypeus narrow and trapezoidal. Anterior margin of labrum distinctly concave. Mandibles with 2 sharp apical teeth and a deep excavation for apical maxillary palpomere at outer side. Maxillary palps 4-segmented, with apical palpomere distinctly widened, truncate apically in male; slightly widened in female. Antennae in male as long as half length of body; antennomere 1 robust; antennomere 2 shorter than 3; antennomere 3 longer than 4; antennomeres 7-11 each distinctly longer than wide; antennomere 11 longest, about 2.48 times as long as wide (Fig. 13). Antennae in female almost reaching elytral humeri; antennomere 11 about 2.38 times as long as wide.
Pronotum. Lateral sides widest near base, roundly moderately narrowed anteriorly, anterior angles strongly produced (Fig. 2). Anterior and lateral margins bordered, lateral margins invisible in dorsal view. Trichobothria present on posterior angles. Disc covered with moderately dense 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 slightly wider than long, narrowed posteriorly.
Elytra. Lateral sides moderately widened posteriorly, widest beyond middle, thence roundly narrowed posteriorly. Humeral calli well developed. Disc covered with 11 regular rows of large punctures, including a short scutellar row; punctures rather irregular between 6th and 8th striae in apical half; interspaces shagreened, covered with fine and sparse punctures. Epipleura wholly visible in lateral view. Hind wings well developed.
Venter. Hypomera weakly rugose, with a few punctures near anterolateral corners of prosternum. Prosternum covered with coarse and dense punctures bearing long setae; prosternal process enlarged apically, bordered laterally, with moderately dense punctures. Metasternum covered with small and moderately dense punctures in median region, large and dense punctures in lateral region. Abdominal ventrites covered with dense punctures bearing short setae.
Legs. Moderately robust. Tibiae widened apically; fore tibia with a blunt toothlike projection; mid and hind tibiae each with a tooth-like projection. Fore legs with tarsomere 1 strongly enlarged, distinctly wider than 3 in male; slightly narrower than 3 in female. Tarsal claws appendiculate.
Genitalia. Aedeagus moderately narrowed apically, with apical process rather long, very slightly tapered apically, apex truncate in dorsal view; moderately curved, with apical process pointed and slightly bent downward at apex in lateral view (Fig. 14). Spermatheca absent.
Etymology. Named after the type locality, Amur region. Distribution. Mongolia, Russia (Far East) (Fig. 16). Diagnosis. This species is very similar to G. springlovae in having large body size, long antennae and similar shape of aedeagus. However, Gonioctena gracilicornis can be distinguished by pronotum with strongly rounded lateral sides (feebly rounded in G. springlovae), pronotum reddish brown, with or with a large black marking, sometimes entirely black (always entirely black in G. springlovae) and aedeagus rather thick (thin in G. springlovae).
Body oblong oval and moderately convex (Fig. 3). Coloration extremely variable. Head black, with reddish brown band near apex of mandibles. Antennomeres 1-5 yellowish brown, sometimes darkened, 6-7 dark brown to blackish brown, 8-11 black. Pronotum reddish brown, with or without a large black marking, sometimes entirely black (Fig. 25). Scutellum black. Elytra reddish brown, with or without 5 pairs of black spots, sometimes enlarged and connected with each other. Venter black, with hypomera and apical margin of last abdominal ventrite reddish brown. Legs black, with tibiae reddish brown except base and inner margin and tarsi dark brown to blackish brown, sometimes tibiae and tarsi largely black. Rarely body almost completely black except antennae.
Pronotum. Lateral sides widest near base, roundly moderately narrowed anteriorly, anterior angles strongly produced (Fig. 4). Anterior and lateral margins bordered, lateral margins well 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 variable in length, as long as wide, longer than wide or wider than long.
Elytra. Lateral sides slightly widened posteriorly, widest beyond middle, thence roundly narrowed posteriorly. Humeral calli well developed. Disc covered with 11 regular rows of large punctures, including a short scutellar row; interspaces shagreened in some specimens, covered with fine and sparse punctures. Epipleura wholly visible in lateral view. Hind wings well developed.
Venter. Hypomera weakly rugose, with dense punctures on anterior side. Prosternum covered with coarse and dense punctures bearing long setae; prosternal process enlarged apically, bordered laterally, with sparse punctures. Metasternum covered with small and sparse punctures in median region, large and dense punctures in lateral region. Abdominal ventrites covered with dense punctures bearing short setae.
Legs. Moderately robust. Tibiae widened apically, with a tooth-like projection. Fore legs with tarsomere 1 enlarged, slightly wider or narrower than 3 in male; distinctly narrower than 3 in female. Tarsal claws appendiculate.
Genitalia. Aedeagus rather thick, moderately narrowed apically, with apical process rather thick in dorsal view; moderately curved, with apical process pointed and slightly bent downward at apex in lateral view . Spermatheca absent.
Host plant. Salicaceae: Salix caprea, S. rorida, S. sachalinensis (L. N. Medvedev 1968); Salix spp. (L. N. Medvedev and Zaytsev 1978, L. N. Medvedev and Dubeshko 1992, Zaytsev and L. N. Medvedev 2009. Remarks. Gonioctena gracilicornis is widely distributed in the Northeastern Palearctic region (Fig. 16) and is slightly variable in the shape of aedeagus (Figs 18-24). Gonioctena gracilicornis var. kiberi, munaguro, signaticollis were described by Chûjô (1941) and synonymized with Gonioctena gracilicornis by Gressitt and Kimoto (1963). However, the type specimens of these variations have not been examined and their taxonomic status needs to be re-examined.  synonymized G. sunk-angensis with G. gracilicornis, however he did not examine the type of G. sunkangensis. We examined types of both species and confirm that both are conspecific. Lectotype label of Gonioctena gracilicornis by L. N. Medvedev has not been published, and thus invalid. Li's record (1992) is probably based on misidentified G. gracilicornis because G. springlovae has not been recorded from China. Female laid larvae which were enclosed within chorion on leaves of Salix sp. in South Korea, therefore this species is ovoviviparous (Fig. 66). Diagnosis. Gonioctena jani sp. n. is closely related to G. amurensis sp. n. in having small body size and similar length of antennae, however it can be distinguished by pronotum with sparse punctures on median region and moderately dense punctures on lateral region (small and moderately dense punctures on median region and large and dense punctures on lateral region in G. amurensis sp. n.) and aedeagus rather thick with relatively short apical process (rather thin with relatively long apical process in G. amurensis sp. n.).
Body oblong oval and moderately convex (Fig. 5). Head black. Mandibles black, with reddish brown band near apex. Maxillary palps reddish brown or dark brown, with apical palpomere black. Antennomeres 1-7 yellowish brown, 1 and 7 slightly darkened, 8-11 reddish brown to dark brown. Pronotum reddish brown, with 3 spots or a large marking (Fig. 28). Scutellum black. Elytra reddish brown, with or without 5 pairs of black spots. Venter black, with hypomera, apical and lateral parts of abdominal ventrites 3-5 reddish brown. Legs black, with tibiae reddish brown except base and tarsi dark brown to reddish brown.
Head. Vertex weakly convex, covered with coarse and dense punctures. Frontal suture V-shaped, coronal suture absent or weak. Frons flat, strongly depressed anteriorly, covered with dense punctures. Clypeus narrow and trapezoidal. Anterior margin of labrum distinctly concave. Mandibles with 2 sharp apical teeth and a deep excavation for apical maxillary palpomere at outer side. Maxillary palps 4-segmented, with apical palpomere distinctly widened, truncate apically in male; slightly widened in female. Antennae in male almost as long as half length of body; antennomere 1 robust; antennomere 2 shorter than 3; antennomere 3 longer than 4; antennomeres 7-11 each distinctly longer than wide; antennomere 11 longest, about 2.22 times as long as wide (Fig. 26). Antennae in female almost reaching elytral humeri; antennomere 11 about 2.33 times as long as wide.
Pronotum. Lateral sides widest near base, roundly moderately narrowed anteriorly, anterior angles strongly produced (Fig. 6). Anterior and lateral margins bordered, lateral margins invisible 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 slightly wider than long, narrowed posteriorly.
Elytra. Lateral sides moderately widened posteriorly, widest beyond middle, thence roundly narrowed posteriorly. Humeral calli well developed. Disc covered with 11 regular rows of large punctures, including a short scutellar row; punctures rather irregular between 6th and 8th striae in apical half; interspaces shagreened in female, covered with fine and sparse punctures. Epipleura wholly visible in lateral view. Hind wings well developed.
Venter. Hypomera weakly rugose, with a few 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. Metasternum covered with small and sparse punctures in median region, large and dense punctures in lateral region. Abdominal ventrites covered with dense punctures bearing short setae.
Legs. Moderately robust. Tibiae widened apically, with a tooth-like projection. Fore legs with tarsomere 1 strongly enlarged, distinctly wider than 3 in male; slightly narrower than 3 in female. Tarsal claws appendiculate.
Genitalia. Aedeagus rather thick, parallel-sided in middle, with apical process rather short, very slightly widened apically, apex rather truncate in dorsal view; moderately curved, with apical process pointed and slightly bent downward at apex in lateral view (Fig. 27). Spermatheca absent.
Etymology. Dedicated to Jan Bezděk (Brno, Czech Republic), the well-known specialist in Chrysomelidae.
Body oblong oval and moderately convex (Fig. 7). Coloration extremely variable. Head black. Mandibles black, with reddish brown band near apex. Maxillary palps reddish brown or dark brown, with apical palpomere black. Antennomeres 1-5 yellowish brown, partially darkened, 6-7 darkened, 8-11 dark brown or blackish brown. Pronotum entirely black or reddish brown with a large black marking, rarely entirely reddish brown (Figs 31-32). Scutellum black, rarely entirely reddish brown. Elytra entirely black or reddish brown, with or without 4-5 pairs of black spots. Venter black, with hypomera reddish brown or black and apical margin of last abdominal ventrite reddish brown. Legs black, with tibiae reddish brown except base and inner margin and tarsi blackish brown or reddish brown, sometimes legs entirely black to dark brown.
Head. Vertex weakly convex, covered with dense punctures. Frontal suture Vshaped, coronal suture weak or absent. Frons flat, strongly depressed at anterior margin, covered with dense punctures. Clypeus narrow and trapezoidal. Anterior margin of labrum distinctly concave. Mandibles with 2 sharp apical teeth and a deep excavation for apical maxillary palpomere at outer side. Maxillary palps 4-segmented, with apical palpomere distinctly widened, truncate apically in male; slightly widened in female. Antennae in male longer than half length of body; antennomere 1 robust; antennomere 2 shorter than 3; antennomere 3 longer than 4; antennomeres 7-11 each distinctly longer than wide; antennomere 11 longest, about 2.68 times as long as wide (Fig. 29). Antennae in female reaching elytral humeri; antennomere 11 about 2.31 times as long as wide.
Pronotum. Lateral sides widest near base, roundly moderately narrowed anteriorly, anterior angles strongly produced (Fig. 8). Anterior and lateral margins bordered, lateral margins not or hardly visible in dorsal view. Trichobothria present on posterior angles. Disc covered with rather dense 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 slightly wider than long, narrowed posteriorly.
Elytra. Lateral sides moderately widened posteriorly, widest beyond middle, thence roundly narrowed posteriorly. Humeral calli well developed. Disc covered with 11 regular rows of large punctures, including a short scutellar row; sometimes punctures rather irregular between 6th and 8th striae in apical half; interspaces shagreened, covered with fine and sparse punctures. Epipleura wholly visible in lateral view. Hind wings well developed.
Venter. Hypomera weakly rugose, with a few 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. Metasternum 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.
Legs. Moderately robust. Tibiae widened apically, with a tooth-like projection. Fore legs with tarsomere 1 strongly enlarged, distinctly wider than 3 in male; very slightly narrower than 3 in female. Tarsal claws appendiculate.
Remarks. The taxonomic status of G. nivosa, and its relationships to G. affinis and G. arctica has been disputed for a long time. Kraatz (1879a) treated G. arctica as a synonym of G. nivosa. Székessy (1934) synonymized G. arctica andG. nivosa with G. affinis, while Bechyně (1948) established them as distinct species. Mohr (1966) regarded G. affinis and G. nivosa as phylogenetically young group that are almost identical. Wilcox (1972) treated G. arctica as a subspecies of G. nivosa. However, Chrysomela affinis Gyllenhal, 1808 is a junior homonym of Chrysomela affinis Fabricius, 1787, therefore Silfverberg (1977 proposed the name G. decaspilota as the oldest available name. He again treated G. decaspilota and G. nivosa as distinct species. All these taxa have been confused until now by many authors (see list above). After examining all type specimens of the discussed taxa and many other specimens from the Holarctic region we conclude that all these taxa are conspecific. The shape of body and aedeagi from Europe, Siberia, Far East and North America are identical, although aedeagi and color patterns slightly vary even within the same population (Figs 31-54). Three type localities of G. nivosa are given in the original description: Kärnten, Berner Alpen and Switzerland. Due to the designation of lectotype, the restricted type locality becomes "Kärnten [= Carinthia in Austria]" (ICZN 1999: Recommendation 74E). Six paralectotypes of Chrysomela affinis Gyllenhal, 1808belong to Gonioctena linnaeana (Schrank, 1781. We examined the type of Phytodecta linnaeana bergrothi and found it is conspecific with G. nivosa. Phytodecta linnaeana bergrothi has been misidentified since its original description and is here synonymized with G. nivosa. The name Phytodecta linnaeanus bergrothi var. simplex published by Jacobson (1901b) is infrasubspecific. It is available from Achard (1924) who first used it for a variety of species, P. linnaeanus var. simplex (ICZN 1999: Article 45.5.1). However, this name and its incorrectly proposed replacement name P. linnaeanus var. mutatus are removed from synonymy with G. linnaeana and are synonymized with G. nivosa based on the original description. Phytodecta nivosa var. cedehensis is for the Alpine specimen having black elytra with a large yellow marking at tip and is synonymized with G. nivosa.
We also examined the types of Phytodecta nivosa var. bicolor Heyden, 1883 and P. flavicornis var. limbatipennis Achard, 1924 and found that they are conspecific with G. flavicornis (Suffrian, 1851). Therefore, they are removed from synonymy with G. nivosa and are synonymized with G. flavicornis.
Several larvae were dissected from the female specimens collected in Norway and Transbaikalia, therefore this species is ovoviviparous (Fig. 67). The previous record of the occurrence of ovoviviparity by Notman (1921) is based on misidentified G. notmani (Schaeffer, 1924). Diagnosis. Gonioctena norvegica differs in having antennae much shorter than half length of body in male, not reaching elytral humeri in female, aedeagus rather thick in dorsal view and strongly curved in lateral view.
Body oblong oval and moderately convex (Fig. 9). Head black. Mandibles black, with dark reddish brown band near apex. Maxillary palps blackish brown, with apical palpomere black. Antennae yellowish brown or reddish brown, generally with last 4-6 antennomeres darkened. Pronotum reddish brown, with small or large black markings (Fig. 61). Scutellum black. Elytra reddish brown, with 4-5 pairs of black spots. Venter black, with hypomera and apical margin of last abdominal ventrite reddish brown. Legs black, with tibiae reddish brown except base and inner margin and tarsi dark brown or reddish brown.
Pronotum. Lateral sides widest at or near base, roundly moderately narrowed anteriorly, anterior angles strongly produced (Fig. 10). Anterior and lateral margins bordered, lateral margins invisible in dorsal view. Trichobothria present on posterior angles. Disc covered with moderately dense punctures; lateral sides covered with much coarser punctures, becoming larger toward base, partially confluent near basal margin; interspaces covered with fine and sparse punctures. Scutellum slightly wider than long, narrowed posteriorly.
Elytra. Lateral sides moderately widened posteriorly, widest beyond middle, thence roundly narrowed posteriorly. Humeral calli well developed. Disc covered with 11 regular rows of large punctures, including a short scutellar row; sometimes punctures rather irregular between 6th and 8th striae in apical half; interspaces shagreened, covered with fine and sparse punctures. Epipleura wholly visible in lateral view. Hind wings well developed.
Venter. Hypomera weakly rugose, with a few 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. Metasternum covered with small and sparse punctures in median region, large and dense punctures in lateral region. Abdominal ventrites covered with dense punctures bearing short setae.
Legs. Moderately robust. Tibiae widened apically, with a tooth-like projection. Fore legs with tarsomere 1 strongly enlarged, distinctly wider than 3 in male; very slightly narrower than 3 in female. Tarsal claws appendiculate.
Genitalia. Aedeagus rather thick, with short apical process in dorsal view; strongly curved, with apical process pointed and slightly bent downward at apex in lateral view (Figs 56-60). Spermatheca absent.
Body oblong oval and moderately convex (Fig. 11). Coloration variable. Head black, with dark reddish brown band near apex of mandibles. Antennomeres 1-5 yellowish brown, generally darkened, 6-7 dark brown to blackish brown, 8-11 black. Pronotum entirely black. Scutellum black. Elytra reddish brown or yellowish brown, with 5 pairs of black spots, generally connected with each other, rarely elytra entirely black (Fig. 65). Venter black, with lateral margins of last abdominal ventrite reddish brown. Legs black, with tarsi blackish brown, sometimes tibiae largely dark brown to reddish brown.
Pronotum. Lateral sides widest near base, feebly rounded, slightly narrowed anteriorly, anterior angles strongly produced (Fig. 12). Anterior and lateral margins bordered, lateral margins well 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 variable in length, as long as wide, longer than wide or wider than long.
Elytra. Lateral sides slightly widened posteriorly, widest beyond middle, thence roundly narrowed posteriorly. Humeral calli well developed. Disc covered with 11 regular rows of large punctures, including a short scutellar row; interspaces shagreened, covered with fine and sparse punctures. Epipleura wholly visible in lateral view. Hind wings well developed.
Venter. Hypomera weakly rugose, with dense punctures on anterior side. Prosternum covered with coarse and dense punctures bearing long setae; prosternal process enlarged apically, bordered laterally, with sparse punctures. Metasternum covered with small and sparse punctures in median region, large and dense punctures in lateral region. Abdominal ventrites covered with dense punctures bearing short setae.
Legs. Moderately robust. Tibiae widened apically, with a tooth-like projection. Fore legs with tarsomere 1 enlarged, slightly wider than 3 in male; distinctly narrower than 3 in female. Tarsal claws appendiculate.
Genitalia. Aedeagus thin, distinctly narrowed apically, with apical process thin in dorsal view; moderately curved, with apical process pointed and slightly bent downward at apex in lateral view (Fig. 64). Spermatheca absent.
Remarks. Gonioctena springlovae is restricted to Hokkaido and Sakhalin, whereas its closely related species G. gracilicornis is widely distributed in the Northeastern Palearctic region. The distributions of these two species overlap only in southern Sakhalin (Fig.  16). The type locality "Kioto [= Kyoto in Honshu]" is probably in error. As Chûjô and Kimoto (1960) mentioned, no single specimen has been collected again in Honshu whereas many specimens have been collected in Hokkaido. This species is ovoviviparous (Takizawa 1976, Kimoto and Takizawa 1994, Kudo and Hasegawa 2003.