Microphor Macquart

Shamshev, Igor V. & Perkovsky, Evgeny E., 2022, A review of fossil taxa of Microphorinae (Diptera, Dolichopodidae sensu lato), with redescription of the Eocene genus Meghyperiella Meunier, Zootaxa 5150 (3), pp. 411-427 : 417

Microphor Macquart

Microphor Macquart, 1827: 139 . Type species: Microphor velutinus Macquart, 1827 (= Microphor holosericeus (Meigen, 1804)) , by subsequent designation ( Rondani 1856).

Microphorus Macquart, 1834: 345 . Unjustified emendation.

Microphora Zetterstedt, 1842: 253 . Unjustified emendation or error, not Microphora Kröber, 1912: 245 (= Therevidae ).

Included fossil species. Microphor rusticus ( Meunier, 1908) : 105 ( Phyllodromia , male and female) (Baltic region, Upper Eocene).

Remarks. Microphor remains a broadly defined group with not quite clear phylogenetic background. The very recently published revision of the North American species provides the first provisional evidence of monophyly of this genus, especially with respect to Schistostoma ( Brooks & Cumming 2022) .

Currently, Microphor comprises 16 known extant and one extinct species. The recent species are distributed mostly in the Holarctic, one species was described from mountains of South China and one unnamed species is known from South Chile ( Chvála 1991; Saigusa & Yang 2003; Brooks & Cumming 2022).

The single fossil species of Microphor was described by Meunier (1908) from Baltic amber recognized in the genus Phyllodromia (Empididae) . Hennig (1971) examined the type series of M. rusticus and indicated the correct systematic position of this species (also designated the lectotype). However, he did not provide a full redescription of M. rusticus but included figures of the female habitus as well as the male head, wing and postabdomen ( Hennig 1971: figs 26–29). It should be noted that M. rusticus may actually be a species of Schistostoma because Hennig (1971) did not separate Microphor and Schistostoma . As recently re-defined, Schistostoma differs from Microphor primarily by medial hypandrial prolongation of the male genitalia ( Brooks et al. 2019; Brooks & Cumming 2022). However, the structure of the hypandrium is invisible on Hennig’s figure 28 (illustrated from the left side and obscured by pregenital segments). In addition, the female of M. rusticus apparently has at least six visible abdominal segments ( Hennig 1971: fig. 26) that matches with another possible apomorphic feature of Schistostoma (versus 5 exposed segments in Microphor ) ( Brooks & Cumming 2022). Microphor rusticus has two pairs of scutellar setae ( Hennig 1971: fig. 26) that is usually present in Schistostoma (versus 3–4 pairs in Microphor ), however, this character is somewhat variable ( Shamshev & Sinclair 2006; Brooks & Cumming 2022). It seems that Hennig (1971: 5, fig. 4) did not illustrate correctly the stylus segmentation in M. rusticus . Actually, the basal article of the stylus is much shorter and hardly distinguishable, contrary to Ulrich (1991: 212; 2004: 235) who considered the basal article to be absent in this species. Microphor rusticus is probably present in Rovno amber. We have examined two very well-preserved inclusions that are apparently a mated male and female (Shamshev & Perkovsky, unpub. data). In addition, an undescribed species with an incomplete vein M 2 found in Rovno amber, which has been mentioned under Meghyperiella , probably is another representative of Microphor . Although Microphor is known from the Eocene, it must exist at least in the mid-Cretaceous because both its closest allies (i.e., Schistostoma and Microphorites ) were recorded from that time.