Thanks Jeff. I think you're right on the genus, and I'll wait for confirmation before moving. I'm wondering if it's an Aulacigaster, if it can be identified to one of the 2 species here in the northeast.

I agree with Aulacigaster. Species is a bit trickier, but Mathis and Friedberg's revision of the genus is available online (BHL, vol 96 pp 583-598). Here's the couplet that distinguishes the two northeastern species:

1. Larger (wing length averaging 2.6 mm), darker, and shinier species; shiny spot on vertex small, at most extended from ocellus halfway to eye margin, sometimes indistinct; anepistemum with ventral 1/3 shiny, bare of microtomentum, bordered dorsally by dense gray microtomentum; katepistemum, coxae, femora, and abdomen strongly shiny, lacking microtomentum, although fore femur sparsely microtomentose anteriorly; acrostichal setulae in two rows along entire length; 1st flagellomere usually blackened on dorsal 2/3; male terminalia; surstylus broad, wider than width of apical portion of aedeagal apodeme ... mcalpinei

- Smaller (wing length averaging 2.35 mm) and duller species; shiny spot on vertex larger and distinct, extended from ocellus 2/3 distance to eye margin; anepistemum usually entirely microtomentose, rarely with a bare, shiny stripe ventrally; katepistemum. coxae, femora, and abdomen not strongly shiny, at least partially covered with microtomentum; acrostichal setulae in a single median row anteriorly, row bifurcated at posterior 1/2-2/5; 1st flagellomere with only dorsal 1/4 darkened; male terminalia; surstylus narrow, narrower than width of apical portion of aedeagal apodeme ... neoleucopeza [this couplet also leads to the southwestern sabroskyi, which can only be separated based on genitalia]

I can only make out a couple of the characters in these photos, but there are clearly 2 rows of acrostichals anteriorly and the shiny spots on the vertex appear to be extending 1/2 of the distance to the eye margin. I think that's probably enough to put this down as A. mcalpinei.