Zhenia xiai Q. Zhang et al., 2016

Zhang, Qingqing & Zhang, Junfeng, 2019, Contribution to the knowledge of male and female eremochaetid flies in the late Cretaceous amber of Burma (Diptera, Brachycera, Eremochaetidae), Deutsche Entomologische Zeitschrift 66 (1), pp. 75-83 : 75-76

publication ID	https://dx.doi.org/10.3897/dez.66.33914
publication LSID	lsid:zoobank.org:pub:AC2CFE6D-8CBB-4A2C-8551-0E1FA8EB9803
persistent identifier	https://treatment.plazi.org/id/0F20E377-9FEF-8BD9-77D5-EC241474840C
treatment provided by	Deutsche Entomologische Zeitschrift by Pensoft
scientific name	Zhenia xiai Q. Zhang et al., 2016
status

Treatment

Zhenia xiai Q. Zhang et al., 2016 Figures 1 View Figure 1 , 2 View Figure 2 , 3b View Figure 3 , 8C View Figure 8

Diagnosis.

Male flies with antennal pedicel subcylindrical; Rs deviating from R clearly distal to M fork; R2+3 meeting R1 just at C (i.e. cell r1 sessile); R4+5 simple; section C between R4+5 and M1 longer than section C between M1 and M2; M1 slightly arched upwards medially, ending behind apex of wing; M3 arched downwards medially; haltere with boot-like knob; abdominal second segment longest; basitarsus of hindleg as long as, or shorter than, tarsomeres II-V combined; genitalia with gonocoxite conical, gonostylus sickle-like, aedeagus relatively short, not reaching hind margin of gonocoxite.

Description.

Male. Body and legs brown (Fig. 1A, C View Figure 1 ), covered with dense short hairs (Fig. 1D View Figure 1 ). Head large, subovate. Eyes large, holoptic, occupying almost whole head (Figs 1A, C View Figure 1 , 2A View Figure 2 ). Antenna thin and short; scape very small, spherical; pedicel elongated, subcylindrical, slightly wider apically than basally; flagellum ovate-oblong, narrower and shorter than pedicel; arista long, slightly longer than scape, pedicel and flagellum combined (Figs 1B View Figure 1 , 2A View Figure 2 ). Mouthparts with only boot-like labellum visible (Fig. 2A View Figure 2 ).

Thorax stout, thicker and longer than head. Scutum distinctly convex; scutellum rather small, triangular. Wing narrow and long, 3.2 times longer than wide, apex of wing round (Figs 1A View Figure 1 , 2A View Figure 2 ). Costal vein terminating at the wing apex; vein Sc short, ending nearly at level of end of distal cell; R1 long, straight; Rs deviating from R clearly distal to M fork, section of Rs stem nearly as long as section bR4 + 5; R2 + 3 almost straight, fused with R1 just at anterior margin of wing; cell r1 narrow and long, fusiform, with no petiole; section of R4 + 5 + M1 separating from anterior margin of cell d nearly at its end, forked distinctly distad to level of the apex of the discal cell, about 10 times longer than section bM2; M1 slightly arched medially, terminating clearly behind wing apex. M2 more or less arched downwards apically; M3 clearly arched downwards apically, M4 absent; cell d hexagonal, nearly 2.7 times longer than wide; m-m long, straight; bM3 short; m-cu long, nearly three times longer than bM3; cell br obviously longer than, but nearly as wide as, cell bm; cell cu (traditionally anal cell) closed with short petiole (Figs 1A View Figure 1 , 2A View Figure 2 ). Haltere thin and long, knob relatively large, boot-like (Fig. 2A View Figure 2 ). Forelegs and midlegs relatively thin and short but with pulvillus and empodium extremely elongated, which are very closely similar in length and in shape to those of hindleg; hindlegs relatively stout and long; coxa stout, obtuse-triangular; femur clavate, nearly as long as half of abdominal length; tibia subcylindrical, slightly shorter and obviously narrower than femur; tarsus very short, nearly one-third of length of tibia, basitarsus shorter than, or nearly as long as, tarsomeres II-V combined, ratio of tarsomeres 1.0:0.24:0.21:0.33:0.55, empodium similar in length and shape to pulvillus, narrowly phylliform in lateral view, less than one-half of length of tarsus (Fig. 2A, C View Figure 2 ).

Abdomen thin and long, subcylindrical, nearly two times longer than head and thorax combined; eight segments visible; first very short, second longest, remainder gradually reduced in length terminally; ratio of segments 1.0:2.2:2.1:1.5:1.5:1.0:0.9:0.8; ninth segment forming male genitalia, nearly as long as eighth (Figs 1A, B View Figure 1 , 2A View Figure 2 ). Genitalia covered with thin and long hairs; gonocoxite stout and long, subconical, basally thicker than apically; gonostylus with dense hairs on outer margin but glabrous on inner margin, relatively small, sickle-like, sharp apically, strongly curved inwards; aedeagus (phallus) relatively short, not reaching hind margin of gonocoxite, simple (not forked apically), rounded apically (Figs 1D, E View Figure 1 , 2B View Figure 2 ).

Dimensions.

Topotype NIGP170824, body length ca 7.8 mm; head length 1.0 mm; thorax length 1.5 mm; wing length 4.4 mm, width 1.4 mm; hindleg length 5.9 mm (coxa 0.5 mm, trochanter 0.2 mm, femur 2.3 mm, tibia 2.1 mm, tarsus 0.8 mm); abdomen length 5.3 mm.

Distribution.

Myanmar amber, Late Cretaceous (Cenomanian); Hukawng Valley, Kachin Province, Myanmar.

Remarks.

Zhenia xiai was erected based on three female flies from Myanmar amber: the holotype BA02-15001 and two paratypes NIGP163430 and BA02-15003 (Q. Zhang et al. 2016). The new male specimen from the same locality demonstrates many close similarities in body structures and wing venation to those of Z. xiai and is assigned to this species. The following characters are shared by the male and females: antennal pedicel elongate, subcylindrical, wider apically than basally; the second abdominal segment longest; basitarsus of hindleg shorter than (or nearly as long as) tarsomeres II-V combined; in wing venation, Rs deviating from R clearly distal to M fork; section C between R4+5 and M1 longer than section C between M1 and M2; M1arched upwards medially, ending behind apex of wing; M3 arched downwards medially (vs Z. burmensis sp. nov. described below). The male differs from those females in that: cell r1 is sessile (vs with short petiole in female); and R4+5 is simple (vs forked apically in female). These differences might be sexually dimorphic or individual variation.

Grimaldi and Barden (2016) described another female fly (AMNH BuSD-2) from the same locality that was assigned to Z. xiai. Indeed, it demonstrates close similarities in body structures and wing venation to those of Z. xiai but differs from the holotype of (BA02-15001) and the paratype (NIGP163430) of this species in that: antennal pedicel is conical, basally clearly thicker than apically (vs subcylindrical, apically thicker than basally); body is covered with dark brown markings dorsally on thorax and on abdominal tergites and sternites (vs no dark brown markings dorsally on thorax and on abdominal tergites and sternites except for the paratype BA02-15003); and the abdominal second to sixth segments are almost equal in length, with the third longest (vs the second longest); ovipositor is fringed with dense hairs ventrally (vs almost glabrous), and relatively shorter and stouter than that of the holotype (Fig. 3 View Figure 3 ). Grimaldi and Barden’s (2016) specimen is very closely similar to the female Z. burmensis sp. nov. (Figs 6E View Figure 6 , 7C View Figure 7 ; see descriptions below). These differences indicate that this fly (AMNH BuSD-2) may not be a member of Z. xiai and is most likely related to Z. burmensis sp. nov. Owing to the same markings on abdominal tergites and sternites, and the almost equal abdominal second to sixth segments in length (Q. Zhang et al. 2016: 3, fig. 1C), the paratype (BA02-15003) may be closely related to the specimen AMNH BuSD-2 rather than to Z. xiai (BA02-15001 and NIGP163430). Unfortunately, it is a poorly preserved specimen, and many taxonomic characteristics are indistinct. Therefore, the placement of the female specimens BA02-15003 and AMNH BuSD-2 is debatable.