Cheilosia ( Cheilosia ) proxima ( Zetterstedt, 1843 )

Bot, Sander, Mengual, Ximo, Meutter, Frank Van de & Skevington, Jeffrey H., 2025, Review of the genus Cheilosia Meigen, 1822 (Diptera: Syrphidae) from the Caucasus, with the description of 14 new species, European Journal of Taxonomy 1023, pp. 1-181 : 112-114

Cheilosia ( Cheilosia) proxima ( Zetterstedt, 1843)

Fig. 57

Eristalis proxima Zetterstedt, 1843: 792 .

Cheilosia proxima – Tóth 1986: 94. — Peck 1988: 114. — Barkalov 1993: 700. — Barkalov & Mutin 2018: 483. — Mengual et al. 2020: 19.

Differential diagnosis

Cheilosia proxima is a member of a group of closely related species, called the proxima group ( Vujić et al. 2013) in which the pilose eyes, posterior margin of scutellum with setae, usually partly yellow legs, continuously pilose katepisternum, pruinose sterna and the shape of postgonite are distinctive characters. For a full diagnosis of the Cheilosia proxima group see Vujić et al. (2013). The male genitalia of C. proxima are figured in Vujić et al. (2013).Within the proxima group, C. proxima is most similar to C. gigantea . For differences, see the Differential diagnosis of C. gigantea .

Material examined

Collected in 2018, 2019, 2021 and 2023; see Mengual et al. (2020) for detailed records from 2018.

Genetics

DNA barcodes of C. proxima from the Caucasus appear clustered in three distinct groups with high support (BS = 99.8%; BS = 100%; BS = 100%). Two of these groups comprise only Caucasian individuals and the third has European and Caucasian specimens. For each group a male is portrayed in Fig. 57 A–C.

Remarks

Specimens from all three distinctly different barcoding groups are also morphologically distinct, they often occurred at different locations, habitats and times of the year, and they could represent three distinct species. However, when testing these groups morphologically against European material, European specimens show a wide variation with intermediate looking specimens. Due to the lack of extensive genetic samples in Europe it remains unknown if the variation found in European specimens of C. proxima might be correlated with some genetic difference as well or not. More molecular data is needed to properly assess the intraspecific and interspecific variability of this very variable and wideranging species.

Biology

During our expeditions, collected between 4 May and 8 July at an altitude between 1090 and 2700 m a.s.l. A species found in meadows and clearings near forest in the lower montane zone to alpine meadows above the treeline, but phenology and habitat (elevation niche) differ between the barcoding clusters.

Distribution

Palaearctic.