Based on this paper (1) and in decreasing order of confidence, Trypoxylon subgenus Trypargilum (“Fore wing with costa not produced beyond radial cell”, “abdominal sternites 2 to 3, usually 2 to 5, bare, with pubescence only at bases of paired bristle”); T. politum (“First abdominal tergite with lateral margins parallel for only a short distance then widening rather abruptly: apex nearly three times as wide as narrowest portion”, “Pubescence of head and thorax black” [they look black to me, at least relative to the guide’s photos of T. lactitarse]

From what features I can see that are used in this paper’s key for subgenus Trypargilum (2), it seems to belong to the “Albitarse group” (“black wasps with yellow white to pale yellow on hindtarsi”). Using the key for females of that group (2) also seems to point to T. politum (Couplet 7: “Gastral segment I robust, strongly flaring laterally from near anterior end”, “hindtibia with spines on anterodorsal surface near base” [barely visible in photo 4], “head width = 4.0-5.9mm” [~4.6mm in this individual], “forewing length 12.0-18.7mm” [~14.7mm in this individual]. Couplet 8: “hindtarsomere V usually yellow white to light brown” (vs. “dark brown to black”). Couplet 9: “Southeastern Ontario and Eastern U.S., head width = 4.6-5.1mm, forewing length = 14.8-16.2mm” (vs. a larger Mexican species, T. giganteum))

After all of that, I’d very much appreciate it if someone with more expertise would confirm or correct that ID. Thanks in advance for the help

(sizes estimated from the photo and the reproduction ratio)