First checklist of the chrysidid wasps (Hymenoptera, Chrysididae) of Mongolia, with description of new species

Abstract An annotated checklist of the Chrysididae from Mongolia is provided. A revision of the bibliographical data is provied, since most of the collecting localities published for “Mongolia” refer to places currently located in China. The known Mongolian cuckoo wasp fauna counts 90 species in 18 genera and two subfamilies. Four genera and 57 species are recorded for the first time, including two species here described as new for science: Cleptes mongolicus Rosa, Halada & Agnoli, sp. nov. (Dornod) and Spinolia spinosa Rosa & Halada, sp. nov. (Bayankhongor).


Introduction
Mongolia is a large landlocked country in eastern Central Asia, covering 1,564,100 km². Politically, Mongolia is divided into 21 provinces named "aimags" with the capital Ulaanbaatar ( Fig. 1). It is bordered by Russia to the north and China to the south, east, and west. Geographically and climatologically, it is an area of contrasts and extremes, between cold mountainous regions up to 4,000 m a.s.l. to the north and west and one of the largest deserts of the world in the south, the Gobi Desert. Most of the country is located on high plateaus, covered by steppes and extensive forested areas. It has an extreme continental climate with long, cold winters and short hot summers, during which most of its annual precipitation falls (Lavrenko 1979;Dathe and Proshchalykin 2016).
Mongolian cuckoo wasps are scarcely known and a few occasional records are found in the literature (Rosa 2017a). Only one article (Móczár 1967) deals with Mongolian material collected by Dr Z. Kaszab during his entomological excursions in this country (1963)(1964)(1965)(1966)(1967)(1968). Other scattered findings have been published (du Buysson 1901;Semenov-Tian-Shanskij and Nikol'skaya 1954;Linsenmaier 1997a;Rosa et al. 2017a, b), while most of the remaining bibliographical data recorded for "Mongolia" actually refer to localities currently included in China (Inner Mongolia, Xinjiang, Gansu) (du Buysson 1893; Radoszkowski 1877Radoszkowski , 1891Mocsáry 1890;Dalla Torre 1892;Bischoff 1913;Hammer 1936;Tsuneki 1947Tsuneki , 1953aLinsenmaier , 1968Kimsey and Bohart 1991;Rosa et al. 2014Rosa et al. , 2015. Approximately 30 species were properly recorded from Mongolia so far (Rosa 2017a) and we here add 57 new records for this country, mostly based on the materials collected by  ZIN) and based on the material collected during the expeditions of V. Roborovskij and P. Kozlov in 1895 andP. Kozlov in 1926. Finally, a few specimens were examined from the material collected in Mongolia by Soviet-Mongolian expeditions in 1967-1982. Soviet-Mongolian expedition were conducted from 1967 to 1983 and led to the collection of extensive entomological material, which became the basis for the publication of numerous articles and books (including Insects of Mongolia in eleven volumes), devoted to the study of various insects families (Proshchalykin and Kuhlmann 2015), although the Chrysididae were never examined by anyone. Large part of the cuckoo wasps collected during these entomological expeditions is still unprepared and unidentified.
Unpublished distributional records from Mongolia were recently published in the volume on Russian Chrysididae , for a better understanding of the distribution of the Asian species, but exact localities were omitted because they were not of interest for that publication. We here report the precise data of species recorded for the first time in Rosa et al. 2019, which are mostly based on material housed in the Linsenmaier collection (Luzern, Switzerland).
In the present paper, based on a comprehensive study of specimens (including primary types) deposited in various collections, we report additional records of 72 species, with two species described as new and 55 species recorded from Mongolia for the first time, resulting in a total number of 90 cuckoo wasps species known from this country ( Table 1).

Materials and methods
Terminology follows Lanes et al. (2020), Hymenoptera Anatomy Ontology (HAO 2020), and partly Kimsey and Bohart (1991). Abbreviations used in the descriptions are as follows: F1, F2, F3, etc. flagellomeres 1, 2, 3, etc., respectively; l/w length/width; MOD anterior ocellus diameter; MS malar space, the shortest distance between base of mandible and lower margin of compound eye; OOL the shortest distance between posterior ocellus and compound eye; P pedicel; PD puncture diameter; POL the shortest distance between posterior ocelli; T1-T5 metasomal terga numbered consecutively, starting with 1 at the second abdominal segment.
Pictures of the types were taken with Nikon D700 connected to the microscope Togal SCZ and stacked with the software Combine ZP. Diagnosis. Cleptes mongolicus sp. nov. belongs to the C. nitidulus species group, based on the pronotum without posterior pit row and without longitudinal median sulcus or posterior median keel. It is closely related only to C. margaritae Móczár, 2000 from Tajikistan, for its general habitus and colouration. The latter belongs to the C. satoi group (Móczár 2000), for the modified pronotal structure, without posterior transversal groove, but with a posteromedian longitudinal keel. Besides the unmodified pronotum, the female of C. mongolicus sp. nov. can be easily separated from the female of C. margaritae by: a) pubescence whitish, shorter on metasoma (max 2.5 MOD) (vs. blackish, longer on metasoma, up to 3 MOD); b) punctation on metasoma with polished T1, shallow and sparse tiny punctures on T2, double punctures on T3 (vs. scattered punctate on T1, densely and evenly punctate on T2 and T3); c) colouration: head entirely black; propodeum entirely blue; T3 and T4 laterally blue; pedicel and F1 yellow; femora apically, tibiae and tarsi yellow (vs. head blue; propodeum black with median blue spot; T3 and T4 fully black; pedicel and flagellum dark brown). The male of Cl. margaritae is currently unknown.
Etymology. The specific epithet is named after the country of origin. Distribution. Mongolia (Dornod).   .
Remarks. Two distinct colour forms ( Fig. 4) are recorded from Mongolia, Siberia and Primorsky Territory (Russia), and Heilongjiang (China). Form A is matching with the typical European Chrysis fulgida (Fig. 4A, C). Form B is chromatic different without the typical blue colouration on male and female metasoma and with non-metallic black areas on head vertex and mesosoma (Fig. 4B, D). Male T1 golden-greenish, with or without a narrow transversal green or bluish stripe or patch; T2 red, with or without a basal, narrow black stripe; female T1 golden-greenish, with green to bluish colour on T1 frontal declivity to petiolar insertion. This colour variation has also been observed in specimens from Russia (Siberia and Primorsky Territory) and China (Heilongjiang). The Chinese form was mentioned by Linsenmaier (1968) as Chrysis aequicolor Linsenmaier, 1968, which is anyway an unnecessary replacement name for Chrysis fulgida var. concolor nec Mocsáry, 1892 (actually male and female of the same taxon). Other evident different morphological characteristics are not recognizable. However, these two forms may represent two sister species, genetically separate, but difficult to identify on the basis of morphological characteristics, as in other known cases of Chrysis of the ignita group (Paukkunen et al. 2015;Orlovskytė et al. 2016).

Chrysis ignita (Linnaeus, 1758)
Sphex ignita Linnaeus, 1758: 571. Lectotype ♀ (designated by Richards 1935); Europe (LSL) (ignita group). Material examined. None examined. (2015) is doubtful and very likely represent another species of the C. ignita group or even a member of another species group (e.g., succincta group). In fact, the host association with Euodynerus dantici, as observed by the two authors, is unusual. Euodynerus dantici is known as a possible host for members of the C. succincta group (C. germari and C. tristicula (sub C. succincta succinctula) Pauli et al. 2019, supplementary file 4). For example, C. dauriana Linsenmaier was erroneously identified as C. ignita by several authors, including Trautmann (identification label pinned with the type of C. dauriana).
Male. Unknown. Etymology. The specific epithet spinosa (feminine) is derived from the Latin adjective spinosus (thorny) for the long and acute teeth ventrally displayed on pronotum and propleuron and clearly visible in lateral view (Fig. 5D).

Elampus spinifemoris
Remarks. Specimens from Mongolia display an unusual red colouration.
From a chorological point of view, one species has a Holarctic distribution (Pseudochrysis neglecta), ten have Palaearctic distributions, one has a Holarctic and Oriental distribution (Omalus aeneus), one a Palaearctic and Oriental distribution (Hedychridium gerstaeckeri), 28 species have an Asiatic-European distribution, 21 have an East Palaearctic distribution, and 19 have a Central Asian distribution.
Another result of the present study is a better knowledge of the distributional limits of some species, and Mongolia represents the easternmost record for seven species: Chrysis aestiva, Ch. illigeri, Ch. jaxartis, Ch. leptomandibularis, Chrysura ignifrons, Elampus albipennis and Philoctetes bogdanovii.
The most widespread Mongolian species is the endemic Philoctetes shokalskii recorded in ten aimags. Chrysis consanguinea and Hedychridium ardens were recorded in nine aimags. This is not surprising because C. consanguinea resulted in being one of the most common species from Western to Eastern Siberia also (Rosa et al. 2017c, d), whereas H. ardens is one of the most common Euro-Siberian species ranging from Central Europe to China (Rosa et al. 2014). Pseudomalus pusillus was recorded in eight aimags, whereas H. cupreum, H. chalybaeum and Philoctetes mongolicus were recorded in seven7 aimags; they are Asiatic-European species, sometimes locally abundant. Hedychridium longigena and Parnopes popovii were recorded in seven aimags, yet they are East-Palaearctic species.
Although most of the Mongolian aimags are under-represented in the existing data due to inadequacy of surveys, based on the currently available data we can state that the highest number of recorded species was collected in Tuv (42 species), Arkhangai (27 species), and Selenge and Dornod (20 species) aimags ( Table 2). The family Chrysididae has not yet been documented from Bayan-Ulgii, Darkhan-Uul, Dundgovi, Khuvsgul, Orkhon, and Uvs although it is probable that this cosmopolitan family is present in these aimags and it is only a matter of time before the fauna is sampled and recorded.
Overall, the Mongolian fauna is still too poorly known for a complete analysis of species richness and composition. The faunal richness of Mongolia is doubtless much higher than we currently know, in comparison with the chrysidid fauna of the adjacent countries and considering the geographic position of Mongolian aimags and their different biotopes. For example, at least another 75 species recorded for Siberia (Rosa et al. 2017d) are expected for Mongolia, as well as other five genera known from bordering and central Asian countries (Chrysidini: Chrysidea Bischoff, 1913, Spintharina Semenov, 1892Elampini: Chrysellampus Semenov, 1932, Haba Semenov, 1954Parnopini: Cephaloparnops Bischoff, 1910). Copious undescribed members of the genus Prochridium Linsenmaier, 1968 were collected in Mongolia. The descriptions of Mongolian Prochridium, and a revision of this genus, are in preparation. Only a single record of an undescribed Prochridium was previously known in literature for Central Asia (Turkmenistan) (Linsenmaier 1994).