Merodon pallidus Macquart, 1842

Vujić, Ante, Radenković, Snežana, Likov, Laura, Tubić, Nataša Kočiš, Popov, Grigory, Gilasian, Ebrahim, Djan, Mihajla, Milosavljević, Marina Janković & Ačanski, Jelena, 2024, Revisions of the clavipes and pruni species groups of the genus Merodon Meigen, 1803 (Diptera, Syrphidae), ZooKeys 1203, pp. 1-69 : 1-69

Merodon pallidus Macquart, 1842 stat. rev.

Merodon pallidus Macquart, 1842: 70 .

Type locality.

Iraq (Baghdad). The original description was based on a single female specimen (holotype identified by Vockeroth in 1969, unpublished). The holotype is located in the Paris Museum ( MNHN): female, Iraq, Baghdad, [specimen dry pinned]. Original labels: [No. 1187. / Merodon / pallidus ] [label handwritten], [Bagdad] [label handwritten], [HOLOTYPE / Vockeroth ‘ 69 ’, ‘ Merodon pallidus / Macquart 1842 / det. Vujić 2008] [red label] (examined).

Notes.

Peck (1988: 173) and Hurkmans (1993: 185) cited Merodon pallidus as a synonym of M. pruni . Hurkmans (1993: 185) designated a “ lectotype ” of M. pallidus based on incorrect interpretation of a male specimen from Baghdad deposited in an unknown collection. Merodon pallidus was described based on one female and there are no indications that the specimen mentioned in Hurkmans (1993) belongs to the type material. A lectotype may be designated from syntypes ( ICZN 1999), but Hurkmans “ lectotype ” was erroneously designated as the type. The identity of the Hurkmans “ lectotype ” could not be validated because this specimen is not located in any museum. Based on our assessment of morphological data, M. pallidus is a valid taxon, which we redefine herein. Based on our analysis of material belonging to distinct individuals collected from Iran, Israel, Pakistan, Palestine and Turkey (10 females, 7 males), the females are conspecific with the holotype of M. pallidus , so we re-describe the male herein.

Diagnosis.

Sternum 3 with long and dense pile medially (Fig. 30 D : marked with arrow). In male the metatrochanter has a less distinct calcar (Fig. 25 D ); metafemur broad (~ 3 × longer than wide), strongly curved, covered with long and dense pilosity ventrally (Fig. 25 D ); sternum 4 in Fig. 28 D . Female with angular metatrochanter and long and sparse pile on metafemur ventrally (Fig. 31 C ). Male genitalia in Fig. 38 . Similar to Merodon aequalis sp. nov. from which differs by sternum 3 with an area of long pilosity medially (Fig. 30 D : marked with arrow) (in M. aequalis sp. nov. sternum 3 has equally distributed pilosity of the same length; Fig. 30 A ); the shape of sternum 4 of male (Fig. 28 D ), which is slightly different in M. aequalis sp. nov. (Fig. 28 A ); and a distinct calcar on the metatrochanter of the male (Fig. 25 D ) and female with an angular metatrochanter (Fig. 31 C ) (in M. aequalis sp. nov. the calcar is almost absent in both sexes; Figs 25 A , 31 A ).

Re-description.

Male. Head. Pedicel and scapus reddish yellow; basoflagellomere from reddish yellow to brown (Fig. 24 C ), short, oval, ~ 1.3 × longer than wide, and ~ 2 × longer than pedicel, concave dorsally; fossette large, dorsolateral; arista reddish to brown and thickened at basal third; arista ~ 2.5 × longer than basoflagellomere; face and frons black, with dense whitish pollinosity; face covered with dense whitish pilosity; pile on frons yellow-whitish; oral margin shiny black, with sparse pollinosity; lunula reddish to brown, bare; eye contiguity ~ 12 facets long; vertical triangle isosceles, shiny, black, covered with grey-yellowish pilosity; ocellar triangle isosceles; occiput with grey-yellow to whitish pile, and grey pollinose; eyes covered with short, whitish grey pile.

Thorax. Scutum and scutellum black with brownish lustre, covered with short, greyish white pile; pilosity near wing bases mostly black; lateral sides of scutum covered with long, golden to the greyish white pile; scutum with five distinct pollinose vittae (Fig. 27 A ); posterior margin of scutellum with long pilosity; posterodorsal part of anterior anepisternum, posterior anepisternum (except anteroventral angle), anterior anepimeron, dorsomedial anepimeron, and posterodorsal and anteroventral parts of katepisternum with dense greyish white pile; wings mostly covered with microtrichia; wing veins yellowish to light brown; calypteres and halteres whitish yellow; angular calcar on metatrochanter distinct; femora black except yellowish apex; metafemur broad, ~ 3 × longer than wide, covered with long whitish pilosity (Fig. 25 D ); tibiae yellow to reddish, except brown medial ring; tarsi yellowish red, in some specimens brown dorsally.

Abdomen. Elongated, ~ 1.3 × longer than mesonotum; tergum 1 black, terga 2–4 usually reddish yellow, in some specimens medially partly black; terga with a pair of broad, distinct silver-grey pollinose fasciate maculae (Fig. 27 A ); pile on terga whitish, medially short, adpressed; sterna brown, covered with long, whitish pile; sternum 3 with an area of long pilosity medially (Fig. 30 D : marked with arrow); posterior margin of sternum 4 with characteristic medial circular structure (Fig. 28 D ).

Male genitalia (Fig. 38 ). Anterior surstylar lobe triangular (Fig. 38 A : al); posterior surstylar lobe large and broad (~ 2 × longer than wide) (Fig. 38 A : pl); cercus trapezoid (Fig. 38 A : c); hypandrium sickle-shaped, without lateral projections; lingula long (Fig. 38 C : l).

Female. Similar to the male except for normal sexual dimorphism and the following characteristics: frons covered with whitish pollinosity; scutum between wing bases with more black pilosity; metafemur narrower (~ 3.5 × longer than wide), with ventral pilosity shorter than in male (Fig. 31 C ); terga 3 and 4 with short adpressed black pilosity medially on dark parts.

Distribution and biology.

The species range includes Iran, Israel, Pakistan, the State of Palestine and Turkey (Fig. 39 ; Suppl. material 2). In Iran, it has been recorded within arid and semi-arid forest ecosystems where Quercus brantii is the dominant vegetation type ( Azizi Jalilian et al. 2020) belonging to the Elburz range forest steppe ecoregion ( Olson et al. 2001). The western part of the range of Merodon pallidus ( Turkey, State of Palestine and Israel) belongs to the Eastern Mediterranean conifer-sclerophyllous-broadleaf forests ecoregions The vegetation of this ecoregion includes maquis, coniferous forests of Pinus halepensis Mill. and P. brutia Ten., dry Quercus spp. woodlands and steppe formations ( WWF 2022). In Pakistan, M. pallidus occurs in warm conifer / mixed forests ( Siddiqui et al. 1999). Flight period: April / August. Developmental stages: not described.

Merodon pruni ( Rossi, 1790)

Syrphus pruni Rossi, 1790: 293 .

Merodon fulvus Macquart, 1834: 514 .

Merodon sicanus Rondani, 1845: 258 , 264.

Merodon fuscinervis Von Röder, 1887: 73 .

Syrphus pruni Rossi, 1790: 293

Type locality. Italy (Toscana). The original description was based on an unspecified number of syntypes ( Rossi 1790: 293). Type material could not be traced ‘ in provinciis Florentina et Pisana’ [Firenze and Pizza, Italy] [not located, not examined]. Based on the description and figure from the original publication ( Rossi 1790), the identity of types is clear and fits the actual concept of species presented in Hurkmans (1993: 185). This species was cited in recent European publications (e. g. Speight 2020; Vujić et al. 2021 a).

Merodon fulvus Macquart, 1834: 514

Type locality. France (“ France méridionale ”). Synonymy with Merodon pruni was cited in Sack (1931), Peck (1988: 172) and Hurkmans (1993: 185). Type material presumably lost.

Merodon sicanus Rondani, 1845: 258 , 264

Type locality. Italy, “ Sicilia ”. The original description was based on two female syntypes. One syntype was designated as a lectotype by Hurkmans (1993: 185): Original label [58] [number referring to the description of Merodon sicanus in the museum’s catalogue of Rondani collection]. This designation was based on syntype (examined) deposited in the LSF.

Merodon fuscinervis Von Röder, 1887: 73

Type locality. Greece (“ Crete ”). Synonymy with Merodon pruni was cited in Sack (1913), Peck (1988) and Hurkmans (1993). Type material presumably lost.

Diagnosis. Sternum 3 with more or less equally distributed pilosity (Fig. 30 E ). In male calcar at metatrochanter distinct (Fig. 25 C ); metafemur medium broad (~ 4.5 × longer than wide), ventral margin slightly curved, and covered with sparse pilosity ventrally (Fig. 25 C ); sternum 4 in Fig. 28 E . Female with angular metatrochanter and sparse pile on metafemur ventrally (Fig. 31 D ). Male genitalia in Fig. 29 . Similar to Merodon obscurus stat. rev. from which differs by posterior surstylar lobe tapering to the tip (Fig. 29 A : pl) (rounded apically in M. obscurus stat. rev.; Fig. 36 A : pl) and its distribution in the Eastern Mediterranean ( M. obscurus stat. rev. is restricted to North Africa).

Distribution and biology. It occurs throughout much of southern Europe ( Italy, Croatia, Greece, Cyprus, Romania), eastwards to Ukraine, Turkey, Armenia, Azerbaijan, Iran, Iraq, Israel, State of Palestine, Lebanon, Pakistan, Turkmenistan, and Tajikistan. Hurkmans (1993) lists North Africa as part of the species range, but those specimens most likely belong to Merodon obscurus . Speight (2020) also mentions Austria and southern France (with the remark that it is most probably extinct), but species presence in those countries could not be confirmed (Fig. 37 ; Suppl. material 2). The preferred environment of species M. pruni is sparsely-vegetated open ground, dry / semi-arid grassland with scattered tall herbs, open areas in low-altitude Abies cephalonica forest on limestone, and Castanea forest ( Speight 2020). At the northern edge of its range, i. e., in Ukraine, the species occurs in steppe habitats. Hurkmans (1985) provides some information on male territorial behaviour; also stating that females fly fast and very close to the ground and are much less noticeable than the males. Both sexes fly silently ( Speight 2020). Flowers visited: Ferula , Foeniculum . Flight period: May / October, with peaks in May and September. Developmental stages: not described ( Speight 2020).

Figures

Figure 24. A – D basoflagellomera, lateral view A M. aequalis sp. nov. B M. obscurus C M. pallidus D M. pruni. E, F head od M. aequalis sp. nov., frontal view A – E male F female. Scale bar: 0.5 mm (A – D); 1 mm (E, F).

Figure 25. Metaleg of male, lateral view A M. aequalis sp. nov. B M. cupreus C M. pruni D M. pallidus E M. obscurus. Scale bar: 1 mm.

Figure 27. Body of male A M. pallidus B M. cupreus C – D M. obscurus E, F M. pruni A, C, E dorsal view B, D, F lateral view. Scale bar: 3 mm.

Figure 28. S 4 of male, dorsal view A M. aequalis sp. nov. B M. cupreus C M. obscurus D M. pallidus E M. pruni. Abbreviations: al-anterior surstylar lobe, c-cercus, l-lingula, pl-posterior surstylar lobe. Scale bar: 1 mm.

Figure 29. Male genitalia M. pruni A, B epandrium C hypandrium A, C lateral view B ventral view. Filamentous prolongation on ejaculatory sack marked with red arrow. Scale bar: 0.5 mm.

Figure 30. S 3 of male, dorsolateral view A M. aequalis sp. nov. B M. cupreus C M. obscurus D M. pallidus E M. pruni. B, D area with distinct long pile marked with arrow. Scale bar: 1 mm.

Figure 31. Metaleg of female, lateral view A M. aequalis sp. nov. B M. obscurus C M. pallidus D M. pruni. Scale bar: 1 mm.

Figure 36. Male genitalia M. obscurus A, B epandrium C hypandrium A, C lateral view B ventral view. Abbreviations: pl-posterior surstylar lobe. Scale bar: 0.5 mm.

Figure 37. Distribution map of Merodon pruni and M. obscurus.

Figure 38. Male genitalia M. pallidus A, B epandrium C hypandrium A, C lateral view B ventral view. Abbreviations: al-anterior surstylar lobe, c-cercus, l-lingula, pl-posterior surstylar lobe. Scale bar: 0.5 mm.

Figure 39. Distribution map of Merodon pallidus.