#1
Found in a semi-urban area just off a small wooded drainage area in Maryland, USA. Of the 3 Nearctic species, I think
Fiebrigella oophaga Sabrosky can be ruled out because it's supposed to have black palpi. However, I can't tell if this one is
F. magnipalpis Becker or
F. catalpae Malloch and am hoping for some expert help
Thanks in advance
Steve
#2
Chloropidae, female: The peculiar structure of the frons speaks for a Lasiambia species, as well the oblique hind crossvein. The extreme tip of the proboscis misses an elongate pair of pseudotracheae, different from most Palaearctic Lasiambia. The male of the type species of Fiebrigella from the Neotropics has highly asymmetric hind claws and an asymmetric end of the hind tarsi (von Tschirnhaus 1992, Decheniana-Beihefte (Bonn) 31: 445-497 [on p. 482-483]). This character has never been recorded from Nearctic Fiebrigella species. First the Nearctic Fiebrigella species must be studied if they have this sexual dimorphisms or if both sexes possess such peculiar hind legs. Polyodaspis and Anacamptoneurum are further closely related genera. Larvae of Lasiambia species, as far as known, are predators of egg masses of grass hoppers (Acrididae).
#3
Dear Dr. von Tschirnhaus,
Thanks for the additional information. If I understand your post correctly, this fly is close to but not definitively
Fiebrigella so I should change the title of the post to avoid confusing later viewers. Any suggestions you have regarding an appropriate taxonomic level would be appreciated.
The taxonomy of this group is certainly too confusing for an amateur like me as it seems to change frequently even within the papers of a single entomologist. Nearctica has
Lasiambia Sabrosky 1941 synonymized under
Fiebrigella Duda 1921 and Cherian has
Fiebrigella synonymized under
Anacamptoneurum (
Acta zoologica cracoviensia, 55(1): 1-32, (2012)).
Malloch's original description of
Fiebrigella catalpae (as
Botanobia) refers to the frons has being "highly glossy, with numerous slight longitudinal striae". Is this a more general characteristic of
Fiebrigella and related genera?
Lastly, I've included a photo of the hind tibia below although it's of unknown utility.
Thanks again for the help
Best wishes
Steve
posterior view of hind tibia showing the tibial organ
#6
The headline is o.k. now, but please Polyodaspis. I have only seen the type specimen of the Neotropic type species of Fiebrigella. In German the frons is repeatedly described as "fett-glänzend" meaning "glossy like fat". The fine striations produce this effect. The whole problem should be postponed as I saw a manuscript which possibly will reject some of the puzzling synonymies. The correct author of Lasiambia is Anonymus, 1937 and not Sabrosky, 1941 or Enderlein, 1936 (published by Evenhuis et al. 2008). Several taxonomic problems more ... Our Canadian expert does not know the Nearctic Fiebrigella species (pers. communication). Try to find a male and check the hind legs if they possess asymmetric claws and asymmetric 4th and 5th tarsal segments. Are those symmetric in your photographed female?
#7
I fixed the typo in the title and have added a new set of photos of the hind tarsal claws. They look fairly symmetrical to me; one may be slightly thicker and curved differently but they're otherwise pretty much the same. This level of magnification is at the limit of what I can photograph and not end up with visual mush.
I'll keep an eye out for a male once the weather here improves.
