New records of Braconinae (Hymenoptera, Braconidae) from South Korea

Two genera (Campyloneurus Szépligeti and Craspedolcus Enderlein) and 31 species of Braconinae are recorded for the first time from South Korea, including one new subspecies (Bracon albion continentalis ssp. nov.). Two new synonyms are proposed: Bracon leptotes Li, He & Chen, 2020, syn. nov. (= B. (Bracon) semitergalis Tobias, 2000) and B. megaventris Li, He & Chen, 2020, syn. nov. (= B. (B.) terebralis Tobias, 2000). For all species with problematic identification descriptions, diagnoses and illustrations are provided.


Introduction
Braconinae are the largest subfamily of the braconid wasps (Yu et al. 2016). The large number of revealed taxa and the lack of adequate literature for identification of most of its species and even genera are complicating the faunistic and taxonomic investigations in the subfamily. The absence of large-scale reviews and revisions of the most common taxa of Braconinae presents a particular difficulty for the study of the East Asian part of the Palaearctic region. The current paper provides a contribution to the fauna of the Korean Peninsula.
First-time records of the species of Braconinae from the Korean Peninsula are found in 14 publications. Except for five recent articles (Lee et al. 2018;Papp 2018;Kang et al. 2019;Samartsev and Ku 2020;Yu et al. 2020), most of the significant literature on the fauna of Korea is cited in the Taxapad catalogue (Cushman 1931;Matsumura 1931;Watanabe 1932Watanabe , 1935Papp 1996Papp , 1998Papp , 2012Belokobylskij and Tobias 2000;Ku et al. 2001; all cited by Yu et al. 2016). A total of 93 currently valid species from 17 genera of braconines have been indicated for the Korean Peninsula. It is notable that 70 species were added by Jenő Papp, mostly on the basis of the material from North Korea. The fauna of South Korea has been less explored.
The present study is based on an extensive collection of Braconinae of South Korea accumulated by the second author. Involving the type material on the species described from the Russian Far East and information on braconines recently described from China and Japan, we add 31 species and 2 genera (Campyloneurus Szépligeti and Craspedolcus Enderlein) to the known fauna of the region. One of the reported species previously known from Europe differs enough to be described as a new subspecies (Bracon albion continentalis ssp. nov.).
In recent years, knowledge about the Braconinae of China develops rapidly (for example, Li et al. 2016Li et al. , 2020a. Due to incompleteness or inaccessibility of information about most of the known species of the subfamily and lack of reliable keys, the risks of misidentification or description of synonymous species during this work are high. For example, two recently described species from China are found to be junior synonyms of species presented in the current article. We provide illustrated descriptions for the species of Braconinae from the East Palaearctic region originally briefly described in Russian (Tobias and Belokobylskij 2000) and for some widely distributed, but complicated in identification species.

Terminology
Morphological nomenclature follows Quicke (1987) and van Achterberg (1993); the transverse pronotal sulcus is included after Karlsson and Ronquist (2012). The length of fifth segment of hind tarsus is measured without its pretarsus; first metasomal tergite is measured from its articulating condyle [term applied after Vilhelmsen et al. (2010)].
Diagnosis. The species is easily recognisable by the following character states: the median area of third metasomal tergite strongly elevated and transverse, with rounded sides and strongly narrowed posteriorly (Fig. 5); third and fourth tergites longitudinally rugose, their apical margins with incomplete, weak and weakly crenulate transverse subapical grooves. See also Li et al. (2020a: 15) for taxonomic literature and additional illustrations.

Genus Bracon Fabricius, 1804
Remarks. The subgeneric classification of the genus requires revision. Most of the Palaearctic species of Bracon are arranged in three subgenera, Bracon s. str., Glabrobracon Fahringer, and Lucobracon Fahringer (Tobias 1986). The species that may be unambiguously attributed to one of the discussed subgenera are more common in the West Palaearctic, but classification of a big part of species is difficult, because they frequently combine diagnostic characters of different subgenera. For example, some of otherwise obvious members of Glabrobracon have the wide hypostomal depression (one of the main characters of the subgenus Lucobracon, e.g. B. brevis Telenga and B. otiosus Marshall), others have the enlarged basitarsi (characterising the section Orthobracon Fahringer of the subgenus Bracon; e.g. B. pauris Beyarslan and B. rozneri Papp). This ambiguity of subgeneric diagnoses caused instability of composition of the main subgenera in interpretation by different authors. For example, the type species of the genus, B. minutator (Fabricius), in violation of the Principle of Coordination has been placed in the section Orthobracon of the subgenus Bracon by Tobias (1986) and together with the most part of the latter section has been transferred to the subgenus Glabrobracon by Papp (2008). These problems are most noticeable in the Far Eastern species which morphological peculiarity has rendered the diagnoses of the main subgenera very diffused and almost inapplicable (Tobias and Belokobylskij 2000). Thus, until reliable criteria of the subgeneric division of Bracon are established, we consider the species of Glabrobracon and Lucobracon in the nominative subgenus. Papp, 1999 Figs 6-10 Bracon (Glabrobracon) albion Papp, 1999: 146. Material examined. United Kingdom -Scotland • 4 females (paratypes); Dunbartonshire, Caldarvan;27 Jun. 1983-7 Jul. 1983 Szépligeti, 1901, female, HNHM) and Bracon (Bracon) albion albion Papp, 1999 (6-10 paratype, female, HNHM) 2, 6 habitus, lateral view 3 head, ventrolateral view 4, 7 head, anterior view 5, 10 metasoma, dorsal view 8 head, lateral view 9 hind tarsus. Scale bars: 0.5 mm (7-10); 1 mm (2)(3)(4)(5)(6) Tobias, 1957, B. munki Papp, 2011, B. pertinax Papp, 1984, and B. terebralis Tobias, 2000 albion differs from all above mentioned species by a combination of strongly enlarged fifth tarsal segment (Fig. 9) and thickened antenna (especially in Europe; Fig. 6 Legs. Fore tibia with longitudinal and transverse apical rows of thick setae. Hind femur 2.4-2.5× longer than wide. Hind tibia 1.5-1.6× longer than hind femur, without subapical row of thick setae, its inner spur about 0.6× (0.65-0.75×) as long as hind basitarsus. Hind tarsus 0.85-0.90× as long as hind tibia. Fifth segment (without pretarsus) of hind tarsus 1.9-2.1× (1.8-1.9×) longer than second segment and 1.2-1.3× longer than hind basitarsus. Claws with rectangular (acute angularly protruding) basal lobe. Metasoma 1.2-1.5× longer than mesosoma. First metasomal tergite with more or less developed dorsolateral carinae composed of multiple rugae and with lateral carinae, its median length 0.80-0.85× its apical width; median area separated by rugate furrow. Second tergite with weak, very short, and narrow triangular median area and weakly impressed dorsolateral impressions, medially 0.75-0.95× as long as third tergite and 0.70-0.75× (0.75-0.85×) as large as apical width of first tergite. Basal width of second metasomal tergite 1.8-2.1× (1.6-1.7×) its median length. Suture between second and third tergites weak laterally, medially deep, weakly curved and crenulate. Apical margins of third to sixth tergites thin, without transverse subapical grooves.
Colour. Body mostly black; legs rusty brown, coxae black, middle and hind femora basally dark brown, or all legs entirely, except for brownish coxae and tarsi, brownish yellow; ventral side of metasoma anteriorly yellowish brown, or metasoma mostly brownish yellow, medio-longitudinally brown; maxillary palps brownish yellow or pale yellow; wing membrane weakly brownish darkened, pterostigma and wing veins brown.

Bracon (Bracon) tergalis Tobias, 2000
Diagnosis. Bracon tergalis may be compared with B. sergeji and B. semitergalis. The differences between three species are presented in the key below.
Diagnosis. Bracon stabilis may be identified using the key provided in Loni et al. (2016: 138). vein SR1, 1.6-1.7× vein 2-SR. Hind femur 3.8-4.3× longer than wide. Hind tibia with 1-2 thick setae subapically. Fifth segment of hind tarsus 0.35-0.40× as long as hind basitarsus, 0.60-0.65× as long as second segment. Claws with large, protruding and blunt basal lobes. First metasomal tergite without dorsal and dorsolateral carinae, its median length 1.1-1.3× its apical width. Second tergite with weak triangle median area and with very shallow s-shaped smooth dorsolateral impressions not bordered by carinae; medially 0.93-0.97× as long as third tergite; its basal width 1.7-1.8× its median length. Second metasomal suture deep, curved and smooth or weakly crenulate. Anterolateral margin of second metasomal tergite at most shortly desclerotised, apical margins of third to sixth tergites widely desclerotised. Ovipositor sheath about 0.65× as long as hind tibia, about 0.2× as long as fore wing. Apex of ovipositor with weak nodus and ventral serration. Head and mesosoma entirely smooth; first tergite weakly rugulose laterally and posteriorly, second and sometimes also third tergite weakly rugulose, but smooth on sides, fourth-fifth tergites hardly granulate to smooth. Body black or brown, legs and palps yellow, apex of hind tibia and hind tarsus brown; wing membrane weakly darkened, pterostigma and veins brown.

Bracon (Orientobracon) maculaverticalis Li, He & Chen, 2016
Diagnosis. Within the subgenus Osculobracon Papp, Bracon cingillus Tobias is most similar to B. subcingillus Tobias, 2000 because of the crenulated furrow of the first metasomal tergite, more or less complete absence of desclerotised areas in anterolateral margins of the second metasomal tergite, and development of sculpture on two basal tergites (Fig. 90). The differences between two species are listed below.
Diagnosis. Cyanopterus tricolor differs from similar species (C. hinoemataensis, C. kusarensis, and C. praecinctus) by the relatively long ovipositor (in related species it is 0.85-1.00× and 0.2-0.3× as long as hind tibia and fore wing, respectively) and absence of transverse subapical grooves on third-fifth metasomal tergites.  Belokobylskij 2000). This indication is based on a single specimen in the collection of ZISP (the label is cited above in the additional material for the species), which also belongs to I. wuhainensis. Remarks. Bracon flaccus Papp, 1996 described from North Korea used to be considered a synonym of Syntomernus asphondyliae (Watanabe) (Tobias and Belokobylskij 2000), but recently has been synonymised with S. sunosei (Maeto, 1991)  . The key to the Eastern-Palaearctic species of Syntomernus is given in Samartsev and Ku (2020: 34). (Maeto, 1991)

Remarks.
The key to the Eastern-Palaearctic species of Syntomernus is provided by Samartsev and Ku (2020: 34). Papp, 1996 Remarks. Uncobracon has been considered either a separate genus (Papp 1996: 168;Tan et al. 2012: 64) or a subgenus of the genus Bracon (Tobias and Belokobylskij 2000: 119;Lee et al 2020b: 242). We follow the first point of view as more justified. Remarks. The diagnosis of the species is provided in Samartsev (2018). Remarks. The keys to the species of Uncobracon is presented in Samartsev (2018) and Li et al. (2020c).

Discussion
This article includes 31 species new to the fauna of the Korean Peninsula, most of which (21 species) have relatively narrow distribution restricted to some regions of China, the Russian Far East, and Japan. Almost all (18) of these Eastern-Palaearctic species were described in 2000 or later and known only by the description or by two works. Therefore, it is too early to discuss the patterns of distribution of these taxa. It is worth noticing the finding of Iphiaulax wuhainensis (from North, Northeast, and East China and South Korea), that is extremely close to I. impeditor distributed from Eastern Europe to Eastern Siberia. Two species are very close and differ mostly by the coloration pattern and development of the body sculpture, but these differences appear to be persistent and the known ranges of the two taxa do not overlap witnessing to the valid status of I. wuhainensis.
The minority of indicated species have been known for a long time as widespread taxa, but have not been recorded in the Korean Peninsula. These are the species with  , and B. (B.) virgatus, have been known only from the western part of the Palaearctic region, and their occurrence in South Korea is quite unexpected. The latter mentioned species, even though it was described from Europe, has the habitus more characteristic of the Far Eastern members of Bracon (the metasoma with areolate sculpture and pale yellow medio-longitudinal stripe and the setose middle lobe of mesoscutum) and shows no related species known in the West Palaearctic.
Current investigation is carried out on the basis of ca. 1800 specimens of Braconinae from the Korean Peninsula stored in the collections of SMNE, NIBR, and ZISP. We have published the results of study of about 35% of this material (in Samartsev and Ku 2020 and current paper). New distributional and taxonomic data added connections between the faunas of East-Asian countries, which seem too disconnected because they for a long time were separately investigated by different scientists and still are understudied. In addition, the conducted work allowed us to provide illustrated diagnoses for 16 complicated in identification species of Braconinae, most of which were described in a scarcely illustrated key in Russian (Tobias and Belokobylskij 2000). Providing relevant diagnostic information on the known East Palaearctic braconines makes them accessible for identification, that is essential in current period, when the fauna of East Asia is becoming intensively investigated.
Most of the unpublished material from South Korea available for us is represented by the taxa similar to widespread species, mostly of the genus Bracon. Identification of this material is difficult, because it requires the involvement of many additional taxa from the West Palaearctic. Nevertheless, we are aimed to finish this work by publishing a review of the fauna of the Korean Peninsula with an analysis of its composition and ties with neighboring regions and keys to species.