Merodon obscurus Gil Collado, 1929

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 obscurus Gil Collado, 1929 stat. rev.

Merodon pruni var. obscurus Gil Collado, 1929: 407 .

Type locality.

Morocco (“ Tanger ”). Merodon obscurus was described as a variety of M. pruni . Holotype: male, Morocco, ( MNCN) [specimen dry pinned]. Original label: [ Tanger, Mz. Escalera / M. pruni var. obscurus Gil Tipo, Gil Collado det. / M. N. C. N. Madrid] (examined).

Notes.

This species was listed as synonym of Merodon pruni by Peck (1988: 173) and Hurkmans (1993: 185). Based on our morphometry and molecular data, this is a valid taxon distributed in North West Africa, far from the range of M. pruni in the Eastern Mediterranean (Fig. 37 ).

Diagnosis.

Sternum 3 with long, equally distributed pilosity (Fig. 30 C ). In male calcar at metatrochanter distinct (Fig. 25 E ); metafemur medium broad, ~ 5 × longer than wide, with ventral margin slightly curved and covered with sparse pilosity ventrally (Fig. 25 E ); sternum 4 in Fig. 28 C . Female with angular metatrochanter and sparse pile on metafemur ventrally (Fig. 31 B ). Male genitalia in Fig. 36 . Similar to Merodon pruni except for the posterior surstylar lobe that is broader (~ 2.2 × longer than wide) and more rounded apically (Fig. 36 A : pl) (in M. pruni the posterior surstylar lobe is ~ 2.5 × longer than wide and tapering to the tip; Fig. 29 A : pl). Merodon obscurus stat. rev. occurs in North Africa, while M. pruni is an Eastern Mediterranean species (Fig. 37 ). Molecular and morphometric data clearly separated these two species (Figs 15 , 16 , 17 , Suppl. material 3).

Distribution and biology.

This species occurs in Algeria, Libya and Morocco (Fig. 37 ; Suppl. material 2). The preferred environment of Merodon obscurus stat. rev. includes sparsely-vegetated open ground and dry / semi-arid grassland with scattered tall herbs. Flowers visited: Ferula , Foeniculum . Flight period: April / September. Developmental stages: not described.

Figures

Figure 15. Maximum Parsimony strict consensus tree based on nine equally parsimonious trees, length 1443 steps, consistency index (CI) 38, retention index (RI) 75. Filled circles represent non-homoplasious changes and open circles are homoplasious changes. Bootstrap supports are depicted near nodes (≥ 50).

Figure 16. Geometric morphometric analysis of the wing shape in males of Merodon clavipes, M. latens sp. nov., M. obscurus, and M. pruni A Position of male specimens in the space defined by CV 1 and CV 2 axes B Position of male specimens in the space defined by CV 1 and CV 3 axes C UPGMA phenogram constructed using squared Mahalanobis distances of wing shape D Drawings showing differences in wing shape for each species pair; differences between the species were exaggerated 5 - fold to make them more discernible.

Figure 17. Wing shape differences among populations of Merodon clavipes, M. latens sp. nov., M. obscurus and M. pruni A Scatter plot of individual scores of CV 1 and CV 2 B Scatter plot of individual scores of CV 1 and CV 3 C UPGMA phenogram constructed using squared Mahalanobis distances of wing shape plotted on the map of Mediterranean basin showing the distribution of populations used in the analysis.

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 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.