Merodon obscuritarsis Palma, 1863: 47

Vujić, Ante, Radenković, Snežana, Tubić, Nataša Kočiš, Likov, Laura, Popov, Grigory, Rojo, Santos & Miličić, Marija, 2023, Integrative taxonomy of the Merodon aberrans (Diptera, Syrphidae) species group: distribution patterns and description of three new species, Contributions to Zoology 92 (1), pp. 51-96 : 57-58

Merodon obscuritarsis Palma, 1863: 47 .

Type locality: Italy, “Sanseverino, Monte Vergine” [= near Naples]. Information concerning the Palma material was missing, type material presumably lost. Synonymy was cited in different publications ( Peck, 1988; Hurkmans, 1993). Description, including the Merodon kneri Mik, 1867: 415 .

Type locality: Ukraine, “Galizien”. Original description was based on an undefined number of male and female syntypes. One syntype was located in the Vienna Museum and is designated as a lectotype. Lectotype (designated here): male, Ukraine (Kreise Czortkow, Podol), ( MNHN), [specimen dry pinned]. Original labels: ‘ Merodon kneri / Mik’, ‘1969’, ‘ LECTOTYPE of Merodon kneri Mik / designated by Vujic A.’. This designation was based on the good condition of the specimen, which was a well-preserved male with clearly visible characters. Synonymy was cited in different publications ( Peck, 1988; Hurkmans, 1993).

Diagnosis: Large (12–15 mm), dark species with bluish to brown or purple lustre; antennae black ( figs. 2A, 2C–D, 2F , 29C, F ); basoflagellomere elongated, about 1.5 times as long as wide ( fig. 29C, F ); abdomen narrow, elongated ( figs.1 , 5A ); body covered with yellow–grey pile, except fascia of black pile between wing bases ( fig. 5C ) and black pile on terga 2–5 medially in females; legs black ( figs. 3A , 4B ); metafemur elongated, about 5 times longer than wide, ventrally covered with pile, as long as half of its width (at least apically) ( fig. 3A ); terga 2–4 each with a pair of narrow, white pollinose, triangular fasciate maculae ( fig. 5A, B ). Male genitalia: posterior surstyle lobe quadratic ( fig. 6A : pl) with well-developed interior accessory lobe ( fig. 6B : il); anterior surstyle lobe large, oval to rectangular ( fig. 6A : al); cercus rectangular ( fig. 6A : c); lingula elongated and narrow ( fig. 6C : l). Similar to Merodon flavitibius , from which it differs in narrower metafemur ( fig. 3A ), and completely black tibiae and tarsi, while partly reddish–yellow in M. flavitibius ( fig. 3C ). Also differs from M. hermonensis sp. nov. in having longer ventral pilosity on metafemur, as long as half of its width, at least apically ( fig. 3A ), while it is about 1/5 of its width in M. hermonensis sp. nov. ( fig. 3B ).

Distribution and biological data: Range ( fig. 7 ): through much of central Europe; from Germany, across the Czech Republic and the Alps ( France, Switzerland, Austria) on to Ukraine and southern European Russia; in southern Europe from Spain eastwards to Italy, Albania, the former Yugoslavia and Greece and further on to Turkey, including Mediterranean islands e.g., Crete. Several authors mention the presence of this species in Morocco ( Séguy, 1961; Claussen, 1989; Dirickx, 1994) and in Spain ( Dirickx, 1994; Marcos-García et al., 2007) without referring to the precise localities where the species occurs. Here, we designate the exact locality from the Spanish records mentioned in the previously published literature. Records from Portugal (Marcos-García et al., 2007; van Eck, Downloaded from Brill.com 08/29/2023 02:13:25AM via free access 2011), albeit possibly true, could not be accurately established. Findings from Lebanon certainly belong to M. hermonensis , while records from Iran ( Khaghaninia et al., 2011; Samin et al., 2016) could be either M. brevis or M. flavitibius , but based on morphological similarity, we suppose it is M. flavitibius . Records from Morocco remain uncertain and unconfirmed. Based on Speight (2020), this species is connected with unimproved, calcareous montane grassland and patchily-vegetated, herb-rich open areas within the Abies forest zone, in the Alps and Pyrenees. At lower altitudes, including Balkanic thermophilous Quercus forest ( fig. 34D ), in South East Europe M. aberrans has been recorded flying high among Tilia trees in flower. In Ukraine, this species inhabits steppe landscapes in the steppe zone and small steppe refugia in the more northern forest regions, excluding very Downloaded from Brill.com 08/29/2023 02:13:25AM via free access dry steppe grassland in the southern parts of the country. Flowers visited: presumably Apiaceae ( Chaerophyllum , Seseli , Sium , Torilis , etc.), Galium , Tanacetum , Tilia . Flight period: May-July and August at higher altitudes. Developmental stages: not described, but in laboratory conditions the larvae of the species feed on Leopoldia comosa bulbs (Popov, unpubl. data).

Figures

FIGURE 1 Male of Merodon aberrans, body, dorsal view. Downloaded from Brill.com08/29/2023 02:13:25AM via free access

FIGURE 2 Head of Merodon aberrans. A) male, lateral view, B) male, dorsal view, C) male, frontal view, D) female, lateral view, E) female, dorsal view, F) female, frontal view. Abbreviation:bf, basoflagellomere.

FIGURE 3 Metaleg of male, lateral view. A) Merodon aberrans, B) M.hermonensis sp. nov., C) M.flavitibius.

FIGURE 4 Metaleg of female, lateral view.A) M.flavitibius, B) M.aberrans.

FIGURE 5 Merodon aberrans. A) abdomen of male, dorsal view, B) abdomen of female, dorsal view, C) mesonotum of male, lateral view.

FIGURE 6 Male genitalia of Merodon aberrans. A) epandrium, lateral view, B) epandrium, ventral view, C) hypandrium, lateral view. Abbreviations: al, anterior surstyle lobe; c, cercus; il, interior accessory lobe of posterior surstyle lobe; l, lingula; pl, posterior surstyle lobe; s, lateral sclerite of aedeagus.

FIGURE 7 Distribution map of Merodon aberrans, Merodon flavitibius and Merodon hermonensis sp. nov.

FIGURE 29 A) Merodon brevis, head of male, lateral view, B) M.brevis, head of female, lateral view, C) M.aberrans, antenna of male, lateral view, D) M.brevis, antenna of male, lateral view, E) M.retectus sp.nov., antenna of male, lateral view, F) M.aberrans, antenna of female, lateral view, G) M.brevis, antenna of female, lateral view, H) M.retectus sp. nov., antenna of female, lateral view.Abbreviations:x, distance from top of basoflagellomere and most prominent point of pedicel; y, width of basoflagellomere at level of base of arista.

FIGURE 34 Photos of localities.A) the habitat of M.flavitibius, Arailer (Armenia), rich mesophilous mountain grasslands, 2100 m asl., B) the joint habitat of M.brevis and M.flavitibius, Boghaqar (Armenia), edges of deciduous mountain forest with shrubs and grasslands, 1340–1400 m asl, C) The habitat of M. brevis, Tsghuk (Armenia).Subalpine meadows, ruderal vegetation (herbaceous legumes, Carduus) on roadsides. 2100 m asl, D) the habitat of M.aberrans, Vršac Mountains, 300 m asl., Serbia. PHOTO BY GRIGORY POPOV (A-C) AND TAMARA TOT (D).