Posted by bradbarnd on 29-01-2025 07:26
#1
Unsure of genus. Collected Groton, Massachusetts on 5 x 2012.
In Manual of Nearctic Diptera, this runs to Sciophilinae (coupl. 25). Not sure about wing micro/macrotrichae (coupl. 28), but going to 29 takes me to Paratinia. Going to 47 takes me to either Tetragoneura (which includes Ectrepesthoneura) or Dziedzickia.
Manual of Central American Diptera leads me to either Undescribed genus B or Dziedzickia.
I feel like I'm way off...
Laterotergite bare.
Mediotergite bare.
R2+3 present.
Sc ends in R.
C extends well past apex of R4+5.
Tibial setae not in rows.
Body length ~3.7 mm
Posted by Dmitry Gavryushin on 19-05-2025 10:18
#2
Well your confusion is understandable since that's a female from a gnoristine genus erected after publication of the Vol. 1 of MND,
Acomopterella Zaitzev, 1989 (New data on taxonomy of Diptera, Mycetophalidae [sic!] of North America. - Zoologicheskii zhurnal 68(12):134-137, in Russian.). The type species,
A. arnaudi Zaitzev (synonym of
A. fallax (Sherman, 1921), described from males collected in Alaska and Canada (NWT); Sherman's material was from BC (Savary I., Vancouver). Zaitzev compares
Acomopterella with
Dziedzickia (with much shorter and more oblique r-m),
Acomoptera and exotic genera of
Austrosynapha and
Schnusea. Zaitzev expressly mentions uniformly dark brown abdomen for his males, Sherman says the dark brown color 'usually more dilute' in females. Abdominal segments of your female appear brown with yellow posteriorly; this fits better
A. fasciata Taber, 2015 from Michigan (a single male), in my opinion rather doubtful species, probably identical with
A. fallax.