Microleptinae, a new subfamily for the fauna of Italy (Hymenoptera: Ichneumonidae)

113 ©Author (s) E-ISSN 2284-4880 ISSN 0429-288X 4.0 INTERNATIONAL Introduction Microleptinae is a small subfamily of Darwin wasps (Ichneumonidae), including 19 species distributed in the Nearctic, Palaearctic and Oriental regions (Yu et al. 2016; Ranjith et al. 2024). The phylogenetic relationships of the group have long been questioned and the subfamily name “Microleptinae” has been used in the past with different meanings, more or less stretched to embrace members of the subfamilies Cylloceriinae, Diacritinae, Orthocentrinae (in part), Oxytorinae, and Tatogastrinae (see Townes 1944, 1971; van Rossem 1981, 1988, 1990; Dasch 1992; Humala 2003; Broad 2004). Currently, the subfamily is restricted to the sole genus Microleptes Gravenhorst, 1829 (Wahl 1986; Quicke et al. 2009; Santos 2017; Broad et al. 2018; Bennett et al. 2019), which includes fi ve species in Europe (van Rossem 1981; Schwarz 1991; Humala 2003). Scant information on biology suggests that Microleptinae are parasitoids of soldier fl ies (Diptera, Stratiomyidae) (Wahl 1986; Schwarz 1991). However, it is unclear whether they are ectoor endoparasitoids and whether they behave as idioor koinobionts (Broad et al. 2018). We report here the fi rst record of the subfamily for Italy, with Microleptes obenbergeri Gregor, 1938 discovered in northern and central Italy. This new fi nding marks an important step in fi lling the knowledge gap of Italian Darwin’s wasp distribution, being the Microleptinae the only subfamily still missing from the checklist of Italian Ichneumonidae (Scaramozzino 1995; Yu et al. 2016) and reaffi rms the need of faunal research on this neglected group of insects in Italy and southern Europe (Di Giovanni et al. 2015, 2025). Material and Methods Digital pictures of the specimens were taken using a Zeiss Axio Zoom V16 microscope. The resulting images were processed with Zerene Stacker for photo stacking. The specimens collected in Lombardy are part of a project to investigate the arthropod diversity of Bosco delle Colombere, a relict lowland oak-forest of the Po Plain (Mola et al. 2023). Depositories: FDGC: Filippo Di Giovanni private collection, Siena, Italy MZUF: Museo di Storia Naturale “La Specola, Università di Firenze Results Microleptes obenbergeri Gregor, 1938 (Figs 1, 2) Material examined. 1♀: Italy: Lombardia, Brescia, Capriano del Colle, Bosco delle Colombere, 45°26’56.4”N 10°09’01.9”E, 25.iv-02.v.2020, Malaise Fragmenta entomologica, 57 (1): 113–116 (2025) Short scientifi c note Submitted: May 4th, 2025 – Accepted: June 9th, 2025 – Published: June 30th, 2025 DOI: 10.13133/2284-4880/1780 Microleptinae, a new subfamily for the fauna of Italy (Hymenoptera: Ichneumonidae) Filippo DI GIOVANNI1,2,*, Martin SCHWARZ3, Giuseppe Fabrizio TURRISI4 1Department of Life Sciences, University of Siena, via Aldo Moro 2, 53100, Siena, Italy – [email protected]; ORCID: https://orcid.org/0000-0002-9811-5599 2NBFC, National Biodiversity Future Center, Palermo, Italy 3Biodiversitätszentrum, Johann-Wilhelm-Kleinstraße 73, 4040, Linz, Austria 4Museo di Storia Naturale “La Specola, University of Florence, via Romana 17, 50125, Florence, Italy – ORCID: https://orcid.org/0000-0002-5258-367X * Corresponding author Abstract The Darwin wasp subfamily Microleptinae is reported for the fi rst time in Italy, with Microleptes obenbergeri Gregor, 1938 discovered in Lombardy and Tuscany. This was the only subfamily of Ichneumonidae (Hymenoptera) of the European fauna not yet recorded for the country. Keywords: Biodiversity; checklist; Darwin wasps; parasitoids; museum collections. Di Giovanni et al. 114 Fig. 1 – Microleptes obenbergeri Gregor, 1938, female; a, habitus, lateral view; b, face, frontal view; c, head and mesonotum, dorsal view. The first known Microleptinae in Italy 115 by one or a few species (i.e., Adelognathinae, Agriotypinae, Alomyinae, Ateleutinae, Collyriinae, Diacritinae, Eucerotinae, Lycorininae, Microleptinae, Neorhacodinae, Orthopelmatinae, Oxytorinae). In the previous checklist of the Italian fauna (Scaramozzino 1995), 33 subfamilies were listed, albeit with a classification or nomenclature sometimes different from the current one. The two subfamilies (both monospecific in Europe), Ateleutinae and Diacritinae, were added by Di Giovanni et al. (2015), leaving the subfamily Microleptinae as the only one still absent from the list of Italian Darwin wasps. The finding of Microleptes obenbergeri reaffirms how much the true diversity of this group in Italy remains still underestimated and highlights the need to fill distributional gaps for many species, some of which can be also relatively common. It should be noted that the new record is also the result of both new sampling (Lombardy) and the studying of extant entomological collections (MZUF), demonstrating how new discoveries can come up both from the investigation of yet little-explored regions and the valorisation of historical repositories. Acknowledgements – FDG wants to dedicate this paper to the memory of the late Livio Mola (Brescia, Italy; 1960-2023), a beloved friend and a curious entomologist. FDG was supported by the NBFC to University of Siena/Department of Life Sciences, funded by the Italian Ministry of University and Research, PNRR, Missione 4 Componente 2, “Dalla ricerca all’impresa”, Investimento 1.4, Project CN00000033. trap, F. Di Giovanni & M. Schwarz det. (FDGC); 1♂: same data as female (FDGC).1♀: Toscana, Arezzo, Riserva Naturale Ponte a Buriano, Penna, iv-v.1998, pitfall trap, B. Cecchi, A. Sforzi & L. Bartolozzi leg., M. Schwarz det. (MZUF); 1♂: Toscana, Arezzo, Parco Nazionale delle Foreste Casentinesi, Monte Falterona e Campigna, loc. Sacro Eremo, 1100 m, 16.vi.1995, P. Abbazzi, L. Bartolozzi, B. Cecchi & A. Sforzi leg., M. Schwarz det. (MZUF). Diagnosis. The species can be distinguished from the other European species of the genus by the following features: 3rd segment of the antenna in the female stocky, less than 3 times as long as wide, uniformly widened towards the apex; male flagellum with tyloids on antennal segments 3 to 4/5/6; clypeus without a median tooth or tubercle; temple slightly widened behind eyes; hind coxa shiny; propodeum with costulae distinct (Gregor 1938; van Rossem 1988; Schwarz 1991; Varga & Kostro-Ambroziak 2021). Distribution. Czech Republic (Gregor 1938); Austria (Humala 2003); Italy (new record). Discussion The parasitoid family Ichneumonidae is currently divided into 42 subfamilies, 36 of which are present in Europe (Broad et al. 2018). 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