Meghyperiella porphyropsoides Meunier, 1908

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 : 414-417

Meghyperiella porphyropsoides Meunier

( Figs 1, 2 )

Meghyperiella porphyropsoides Meunier, 1908: 112 , pl. 8, figs 5–7. Type locality: Baltic region, Upper Eocene.

Meghyerellia porphyropsoides: Keilbach, 1982: 369 , error ( Spahr, 1985: 45).

Notes on type series. Meunier (1908) mentioned two males and one female. However, Ulrich (2004; unpublished notes on Meunier’s types) found only one syntype male in GZG ( Meunier 1908: 112, no. 5323, R. Klebs’s Collection), and the remaining two syntypes are probably lost. We were only able to examine photographs of this inclusion (should be the lectotype). The amber piece has Meunier’s no. 5323 (new no. GZG.BST.00176). In addition, there is a Museum label with hand-written specific name (Z5323, Meghyperiella porphyropsoides ♂) and Hans Ulrich’s hand-written label (Z5323, Microphorinae , M2 reduziert, H. Ulrich 2001). The specimen is in good condition.

Material examined. Ukraine, Rovno amber: OL-39 , Ukraine, Zhitomir Region, Olevsk, Rovno amber, Upper Eocene (1 ♂, SIZK); LKV-1012 , Ukraine, Rovno Region, Veselukha river valley, Rovno amber, Upper Eocene (2 ♂, SIZK) .

In addition, we have examined photographs of the male and female specimens from the personal collection of Hans Ulrich (housed at ZFMK) ( Ulrich 2004: 235).

Diagnosis. Small (body nearly 2 mm) blackish flies; wing with two M veins beyond the discal cell (apical section of M 2 absent); vein closing discal cell (i.e., base of M 2 + dm-m crossvein) smoothly undulating.

Redescription. Male ( Fig. 1 ). Blackish. Body length 1.7–1.8 mm, wing length 1.5 mm. Head. Frons entirely obliterated by eyes. Face and clypeus recessed in oral cavity. Face broad, subrectangular. Ocellar triangle with 2 stronger, moderately long, almost parallel, proclinate ocellars and minute postocellars. Occiput with series of 8–9 visible postocular setae per side. Postgena covered with setae. Antenna with scape short, about half length of pedicel; pedicel about 2X longer than wide, with several setae; postpedicel subtriangular; gradually narrowing nearly beyond basal fourth to third, 3.5–4X longer than wide; stylus arista-like, terminal, about 2.3–2.5X longer than postpedicel, 2-articled, basal article short. Palpus with scattered short setae.

Thorax. Proepisternum with 1 short seta on upper part. Postpronotal lobe with 1 strong, long and 1 short, weak seta. Mesonotum with 1 moderately long presutural supra-alar (with several shorter supplementary setae); 2 long notopleurals (with some additional short weak setae); 1 long postalar; scutellum with 6 setae (middle pair very long, lateral pairs short); rows of acrostichal and dorsocentral setae separated by bare space; acrostichals short, quadriserial, lacking on prescutellar depression; dorsocentrals uniserial, numerous, apparently 11–12 setae per row, short and closely spaced anteriorly, becoming longer posteriorly, 2 posterior-most setae (prescutellars) strong and widely separated.

Legs. Coxae with scattered setae of different lengths. Fore and mid femora with complete rows of 8–9 short to moderately long (2–3 subapical setae on fore femur) posterodorsal setae, some slightly prominent setae anterodorsally; hind femur with complete row of moderately long setae dorsally (slightly shorter than femur width) and complete row of mostly short anteroventral setae (3–4 subapical setae longer). Fore and mid tibiae with somewhat longer setulae dorsally; hind tibia with more or less distinct row of short setae dorsally. Tarsomeres of all legs covered with simple setulae. Tarsal claws, pulvilli and empodium normally developed on all legs.

Wing membrane uniformly faintly infuscate. Calypter brownish, brown fringed. Halter brownish.

Abdomen with tergites 1–6 bearing numerous moderately long, uniform setae, sternites 1–6 with similar sparser setae; segments 7–8 obscured from view.

Terminalia small. Right epandrial lamella narrowed toward apex, with some hardly distinguishable, short apical lobes (surstyli?). Left epandrial lamella obscured from view. Hypandrium with basal part convex, broad apical lobes of subequal lengths; probably bearing 3 long setae on each side. Postgonites obscured from view. Phallus tubular, with tip not narrowed, phallic process (if developed) obscured from view. Hypoproct (if developed) and cercus obscured from view.

Female. Similar to male except for following characters: head dichoptic; eyes smaller; dorsal and ventral ommatidia similar in size. Mesoscutum with slightly less pronounced arch. Wing with anal lobe slightly smaller.

Remarks. Amongst the genera placed in the “ Microphorinae ” lineage of Dolichopodidae sensu lato, Meghyperiella should be compared primarily with Pristinmicrophor because they both possess a wing with only two M veins beyond the discal cell (apical section of M 2 absent). Pristinmicrophor (with single species P. hukawngensis Tang, Shi, Wang & Yang ) was described very recently from mid-Cretaceous amber of northern Myanmar ( Tang et al. 2019). However, Pristinmicrophor hukawngensis can be readily distinguished from Meghyperiella porphyropsoides by several distinctive characters and these species are undoubtedly non-congeneric (see below for additional discussion). According to the original description, P. hukawngensis has a wing with very narrow, almost parallelsided cell dm (versus cell dm broadened toward apex in M. porphyropsoides ) and dichoptic eyes in the male (versus holoptic in M. porphyropsoides ). Archichrysotus is another “microphorine”-like genus possessing a wing with only two M veins beyond the discal cell ( Negrobov 1978; Cumming & Grimaldi 1999). However, species of this group share one-articulated arista-like stylus (versus two-articulated in M. porphyropsoides ) and they are classified in the “ Parathalassiinae ” lineage ( Cumming & Brooks 2002; 2019), which is followed herein.

Actually, Meghyperiella belongs to the Microphor genus group and provisionally this genus is most closely related to Microphor and Microphorites primarily because they share the female syntergite 9+10 with acanthophorous setae ( Cumming & Brooks 2002). A unique feature of Meghyperiella porphyropsoides among all microphorines is the smoothly undulating vein closing cell dm (base of M 2 + dm-m crossvein).

It is interesting to note that Collin (1961: 320) mentioned female specimens of Microphor crassipes Macquart with “very much abbreviated” apical section of M 2. In addition, we have seen a female of an undescribed species of probably Microphor from Rovno amber with similar venation.

It seems that Meghyperiella porphyropsoides was not an uncommon species in the Upper Eocene on the territory of the modern Baltic region and Ukraine. Meghyperiella porphyropsoides is the first amber brachyceran, reported from Zhitomir Region of Ukraine (one rhagionid was determined earlier by B.B. Rohdendorf to family level). Fourteen amber species have been reported from this region ( Legalov et al. 2021b; Radchenko et al. 2021), including new ant species, a new anthribid ( Legalov et al. 2021a), a new curculionid ( Legalov et al. 2022), two new genera and four new species of gall midges ( Fedotova & Perkovsky 2015, 2017), a new micro-caddisfly (Melnitsky et al. 2021); an additional new cicadellid genus and species is described from closely connected fauna of Perebrody ( Dietrich et al. 2021). Veselukha river valley ( Lyubarsky and Perkovsky 2020; Melnitsky et al. 2021b; Giłka et al. 2021) as well as Voronki ( Simutnik et al. 2021; Yamamoto et al. 2022) and Velyki Telkovichi ( Legalov et al. 2022) is one of the most important amber-bearing sites of the Varash district of Rovno Region. Two males were cut from a piece obtained from the private collection of M.R. Khomych (Rovno) that comprises four additional males, supposedly of the same species.

Figures

FIGURES 1, 2. Meghyperiella porphyropsoides Meunier, male, Rovno amber. 1. Habitus, right lateral view; 2. Wing and terminalia. Abbreviations: CuA+CuP —anterior branch of cubital vein + posterior branch of cubital vein; dm—discal medial cell; dm-m—discal medial crossvein; epand—epandrium; hypd lb—apical lobe of hypandrium; M1, M2, M4—medial veins; ph—phallus; R1, R2+3, R 4+5 —radial veins.