Pioneeria, Grimaldi, 2016

Grimaldi, David A., 2016, Diverse Orthorrhaphan Flies (Insecta: Diptera: Brachycera) In Amber From The Cretaceous Of Myanmar: Brachycera In Cretaceous Amber, Part Vii David A. Grimaldi, Bulletin of the American Museum of Natural History 2016 (408), pp. 1-132 : 67

Pioneeria , new genus

DIAGNOSIS: Antenna subcylindrical, with three flagellomeres (2 apical ones short), plus minute apical style. Proboscis short but labium exposed; neck long, with stiff setae dorsally, long pilosity laterally. Four notopleural, one supraalar macrosetae; mesotibia with two spurs. Wing slender, sc-r crossvein present, cell br only slightly longer than bm; R 4 moderately sinuous, slightly longer than R 5; cell d narrow, long; cell cup closed (CuA 2 and A 1 meeting at wing margin); A 2 well developed, terminating abruptly; anal lobe well developed. Terminalia unknown. Distinguished from Pseudorhagio Q.-Q. Zhang et al. ( Zhang et al., 2016) as discussed below under Comments.

TYPE SPECIES: Pioneeria bombylia , new species.

ETYMOLOGY: From the English pioneer, originally from Old French, paonier (“foot soldier”). In reference to the early appearance of this fossil for the family Bombyliidae . The gender of the name is feminine.

COMMENTS: The antenna is unique within Bombyliidae , possessing a subcylindrical flagellum with two short apical articles. Another distinctive feature is the two (vs. one) mesotibial spurs. Unfortunately, the terminalia were lost at the surface of the amber.

Pseudorhagio zhangi Q.-Q. Zhang, J.-F. Zhang, and Wang was recently described in Burmese amber, placed in Tabanomorpha family incerta sedis because it has such unusual features for that infraorder ( Zhang et al., 2016). Disparate features include the following: R 4 strongly curved at base and very sinuous; scutum very arched, such that the neck and dorsum of the head are well below the dorsum of the scutum; crossvein m-cu is very sinuous; flagellum is long, stylate and 1-articled; there are two M veins; spurs 0-2- 0; and the female abdomen has a thick brush of fine setae on the terminal segments.

Indeed, Pseudorhagio is unusual for Tabanomorpha , because it is actually an asiloid, specifically in the Bombyliidae . In fact, it bears important similarities to Pioneeria , such as two long mesotibial spurs, a hunchbacked scutum, the antennal structure (the fine sutures between the apical two flagellar in Pioneeria are very subtle, and may have been missed by Zhang et al.; these authors did not mention the minute apical style, which appears to be present in their fig. 2B). The thick apical brush on the abdomen confirms placement in the Bombyliidae . The only structure in contradiction with an asiloid placement is that the empodium in Pseudorhagio is described as pulvilliform, although in their figure 4A there does not seem to be three pretarsal lobes (only two), so this feature also needs to be independently confirmed. Pioneeria differs from Pseudorhagio by the following: R 4 much less sinuous; wing more slender; scutum with five macrosetae on each side, fringe of long setae on scutellum and posterolateral portion of scutum (vs. without); neck long and setose.