New records of the genus Microleptes (Hymenoptera: Ichneumonidae: Microleptinae) from Ukraine

 Українськаентомофауністика2025,16(1):25–28  Датапублікації:8.10.2025 Ukrainska Entomofaunistyka 2025 16(1) ISSN 2078–9653 http://doi.org/10.5281/zenodo.17295097 urn:lsid:zoobank.org:pub:7A5AD9DF-BA45-4534-9DA5-1CB5C1875E5A NEW RECORDS OF THE GENUS MICROLEPTES (HYMENOPTERA: ICHNEUMONIDAE: MICROLEPTINAE) FROM UKRAINE O. Varga I.I. Schmalhausen Institute of Zoology, NAS of Ukraine Bohdana Khmelnytskoho St. 15 Kyiv, 01054 Ukraine ORCID: http://orcid.org/0000-0002-6285-7830 E-mail: sancho.var[email protected] Varga, O. New records of the genus Microleptes (Hymenoptera: Ichneumonidae: Microleptinae) from Ukraine. — This paper provides an undated list of the Ukrainian species of the genus Microleptes Gravenhorst, 1829. Two species are recorded from Ivano-Frankivsk Region for the first time, of which M. salisburgensis Schwarz, 1991 is the first record from Ukraine. Microleptes splendidulus Gravenhorst, 1829 is excluded from the Ukrainian checklist as all national records of this species belong to M. obenbergeri Gregor, 1938 (misidentification). Key words: Darwin wasps, parasitoids, new records, Ukrainian Carpathians. Варга, О. Нові знахідки з роду Microleptes (Hymenoptera: Ichneumonidae: Microleptinae) в Україні. — Оновлено список українських видів з роду Microleptes Gravenhorst, 1829. Два види вперше виявлено на території Івано-Франківської області, з яких M. salisburgensis Schwarz, 1991 – вперше вказано для України. Microleptes splendidulus Gravenhorst, 1829 у зв’язку з помилковим визначенням вилучено зі списку видів України, оскільки всі національні знахідки цього виду належать до M. obenbergeri Gregor, 1938. Ключові слова: їздці-іхневмоніди, паразитоїди, нові знахідки, Українські Карпати. Introduction Microleptes Gravenhorst, 1829 is a relatively small genus of the subfamily Microleptinae comprising 19 species, of which 5 species are distributed in Europe (Schwarz, 1991; Humala, 2007; Yu et al., 2016; Ranjith et al., 2024). Three species of the genus have been recorded from Ukraine so far (Varga, 2024). This year, yellow pan traps were placed by the author in swampy areas covered with alder inside the two Precarpathian deciduous forests resulting in the collection of several specimens of two Microleptes species, including the rare M. salisburgensis Schwarz, 1991, which is the first Ukrainian and the second European record of the species after the original description. It is significant that the type series of this species was collected in similar habitat, the herb layer of a floodplain forest (Alnetum incanae) situated S of Salzburg (Austria) (Schwarz, 1991). Material and Methods The voucher specimens treated in this study were collected with thirty-five yellow pan traps placed by the author in two swampy areas among the Precarpathian deciduous forests 12 and 23 km SW of Ivano-Frankivsk in 2025 (Figs 1–4). The specimens are deposited in the collection of the Schmalhausen Institute of Zoology, NAS of Ukraine, Kyiv (SIZK). Images of the specimens were taken using a Leica Z16 APO microscope equipped with Leica FLEXACAM C1 camera and processed by LAS Core software at SIZK. Microleptes obenbergeri Gregor, 1938 (Figs 5–6) Varga & Kostro-Ambroziak (2021); Varga (2024): “Microleptes splendidulus” (misidentification) Material examined. Ukraine: 13 ♂, 23 ♀: see papers above. Diagnosis. This species can be distinguished from congeners by the combination of the following characters: face smooth and shiny; clypeus without an apical tubercle; Українська ентомофауністика 2025 16(1) О. Варга Нові знахідки з роду Microleptes (Ichneumonidae) в Україні 26 Figs 1–4. The study localities: 1 – distributional map, 2 – general view of swampy habitat in ‘Zhbyr’ forest, 3 – yellow pan traps placed in ‘Mochary’ forest, 4 – yellow pan traps placed in ‘Zhbyr’ forest. Figs 5–8. Microleptes spp., female: 5–6 – M. obenbergeri, 7–8 – M. splendidulus, 5, 7 – antenna, 6, 8 –head in dorsal view . Scale bars: 0.1 mm. O. Varga New records of the genus Microleptes (Ichneumonidae) from Ukraine Ukrainska Entomofaunistyka 2025 16(1) 27 temples widened behind eyes in dorsal view (Fig. 6); antenna stout, with 14 (female) or 16 (male) flagellomeres, in female first flagellomere 1.4–1.5 times as long as maximum width, widened apically, median flagellomeres more or less quadrate (Fig. 5); in male first flagellomere shorter than second flagellomere, first three flagellomeres with tyloids; propodeum with costulae present. Distribution. Czech Republic (Schwarz, 1991); Italy (Di Giovanni et al., 2025); Ukraine: in the Transcarpathian Region as M. splendidulus (Varga & Kostro-Ambroziak, 2021; Varga, 2024), the record from Austria in Humala (2003) seems to be mistaken. Remarks. Microleptes obenbergeri is a rare European species known so far only from the type specimen collected in Brno (Czech Republic). This species is very similar to M. splendidulus and differs only slightly in the shape of the temples and thickness of the antenna, characters which are however poorly illustrated in Schwarz (1991) and thus are difficult to interpret. Consequently, a large series of specimens collected in the oak forest near Vynogradiv (Transcarpathia) was erroneously identified and published as M. splendidulus (Varga & KostroAmbroziak, 2021; Varga, 2024). However, a well-illustrated recently published record of M. obenbergeri from Italy and the discovery of a specimen of the true M. splendidulus among unsorted materials at SIZK (collected in the Russian Far East, Kunashyr island) made it possible to remove the ambiguity in the distinction of these two species. Females of the two species can be separated based on the widened temples (Fig. 6) and quadrate median flagellomeres (Fig. 5) in M. obenbergeri in contrast to narrower temples (Fig. 8) and distinctly transverse flagellomeres (Fig. 7) in M. splendidulus. Identification of males remains a challenge: the species can be distinguished only on the basis of the shape of the temples. Curiously, the recent key provided in Ranjith et al. (2024) stated that male of M. obenbergeri has slightly narrowed temples compared to subparallel ones in M. splendidulus, but based on the female morphology these criteria should probably be reversed. All the examined Ukrainian males of M. obenbergeri have temples only slightly narrower than in females. I have examined in addition two males with narrower temples collected near Ivano-Frankivsk (Precarpathia), but the identity of these specimens remains unclear since there are no females associated with them. Microleptes rectangulus (Thomson, 1888) Material examined. Ukraine: Ivano-Frankivsk Region, Zhbyr, deciduous forest, 35 yellow pan traps, 48.769347, 24.470242, 14–15.07.2025, 2 ♀ (O. Varga) (SIZK); idem, but 15–20.07.2025, 1 ♀; idem, but 21.07.2025, 2 ♀; idem, but 22–23.07.2025, 2 ♀; idem, but 23–26.07.2025, 1 ♀. Diagnosis. This species can be distinguished from congeners by the combination of the following characters: face smooth and shiny; clypeus with an apical tubercle; antenna slender, with 15 flagellomeres, female first Figs 9–13. Microleptes salisburgensis: 9–11 – female, 12–13 – male, 9, 12 – habitus in lateral view, 10 – face in frontal view (projection arrowed with red), 11 – head, mesosoma and metasomal tergites 1–2 in dorsal view, 13 – head in fronto-lateral view and base of antenna (projection arrowed with red, tyloids arrowed with green). Scale bars: 0.5 mm (9, 12), 0.1 mm (10–11, 13). Українська ентомофауністика 2025 16(1) О. Варга Нові знахідки з роду Microleptes (Ichneumonidae) в Україні 28 flagellomere 4.5–4.8 times as long as maximum width, male with tyloids on flagellomeres 5–8; propodeum smooth, costulae present. Distribution. Europe, Russian Far East, Japan, and Korea (Yu et al., 2016); Ukraine: Transcarpathian (Varga, 2024) and Ivano-Frankivsk (first record) Regions. Microleptes salisburgensis Schwarz, 1991 (Figs 9–13) Material examined. Ukraine: Ivano-Frankivsk Region, Mochary, deciduous forest, 35 yellow pan traps, 48.823424, 24.582265, 03– 08.06.2025, 1 ♂, 2 ♀ (O. Varga) (SIZK). Diagnosis. This species can be distinguished from congeners by the combination of the following characters: face smooth and shiny, with a rectangular projection in the upper half; clypeus without an apical tubercle (Figs 10, 13); antenna stout, with 14–17 flagellomeres, female first flagellomere 2.2–2.4 times as long as maximum width, male first three flagellomeres about the same length, with tyloids (Fig. 13); propodeum rugulose, costulae absent (Fig. 11). Distribution. Austria (Schwarz, 1991), Ukraine (first record), Mongolia (Humala, 2003), Russia (Chita Oblast and Prymorsky Krai) (Humala, 2007). The author is deeply grateful to Anthony Galsworthy (The Natural History Museum, London, United Kingdom) for the proofreading and language correction on the earlier version of the manuscript. References Di Giovanni, F., Schwarz, M. & Turrisi, G. F. 2025. Microleptinae, a new subfamily for the fauna of Italy (Hymenoptera: Ichneumonidae). Fragmenta entomologica, 57(1): 113–116. DOI: 10.13133/22844880/1780 Humala, A. E. 2003. Ichneumon-flies of the fauna of Russia and surrounding countries. Subfamilies Microleptinae & Oxytorinae (Hymenoptera: Ichneumonidae). Russian Academy of Science. Moscow. 1–175. (in Russian) Humala, A. E. 2007. Orthocentrinae. In: Lelej A. S., ed. Key to the insects of Russia Far East. Vol.IV. Neuropteroidea, Mecoptera, Hymenoptera. Pt 5, Vladivostok: Dalnauka, 680–717. (in Russian) Ranjith, A. P., Humala, A. E., Priyadarsanan, D. R., Butcher, B. A. 2024. Discovery of the subfamily Microleptinae (Hymenoptera, Ichneumonidae) from India and Thailand with the description of five new species. Journal of Hymenoptera Research, 97: 1257– 1284. https://doi.org/10.3897/jhr.97.131822 Schwarz, M. 1991. Eine neue Art der Gattung Microleptes Gravenhorst (Ichneumonidae, Hymenoptera) aus Österreich. Linzer Biologische Beiträge, 23(1): 399–405. Varga, O. 2024. Checklist of the Ichneumonidae (Insecta, Hymenoptera) of Ukraine. Zootaxa, 5456(1): 001–131. https://doi.org/10.11646/ zootaxa.5456.1.1 Varga, O. & Kostro-Ambroziak, A. 2021. New records of the subfamilies Cylloceriinae and Microleptinae (Hymenoptera, Ichneumonidae) from Eastern Europe. Zoodiversity, 55(6), 485–492. https://doi. org/10.15407/zoo2021.06.485 Yu, D. S., van Achterberg, C. & Horstmann, K. 2016. World Ichneumonoidea 2015. Taxonomy, biology, morphology and distribution. Taxapad interactive catalogue. Nepean, Ottawa. [database on flash-drive] Received 17.07.2025 Accepted 30.09.2025 Published 8.10.2025 © 2025 O. Varga