Tribe Tachyusini C.G. Thomson

Revised key to the northern American genera of Tachyusini

(Adapted from Klimaszewski et al. 2018, Brunke et al. 2021; for additional illustrations to this key see Brunke et al. 2021)

1. Impression of abdominal tergites with very fine punctures similar to those on pronotal disc............................2

- Impression of abdominal tergites with coarse punctures to finer punctures on pronotal disc or impressions glabrous without punctation........................................................................................... 3

2. Pronotum with pubescence directed straight posteriad; hind tarsus subequal in length to hind tibia or longer............................................................................................ Brachyusa Mulsant & Rey

- Pronotum with pubescence directly posteriolaterad from midline; hind tarsus shorter, slightly longer than half the length of hind tibia or shorter....................................................................... Paradilacra Bernhauer

3. Impression of abdominal tergites glabrous without punctation (Figs. 12a, 13a)................................................................................................... Belladonna Klimaszewski and Chandler, gen. n.

- Impressions of abdominal tergites with coarse punctation...................................................... 4

4. Abdomen clavate, at base distinctly narrower than head; tergite III about as long as wide or longer; tergal impressions with median carina.......................................................................... Tachyusa Erichson

- Abdomen at most slightly constricted at base, subequal to or wider than head; tergite III about twice as wide as long or wider; tergal impressions never with median carina................................................................ 5

5. Abdomen at base elongate and moderately constricted, about as wide as head; tergite III at most twice as wide as long; tergal impressions deep and sharply delineated from strongly convex disc......... Dasygnypeta Lohse, (sensu Brunke et al. 2021)

- Abdomen at base almost as wide as elytra or slightly constricted, wider than head; tergite III strongly transverse, ~ 2.5 × wider than long or wider; tergal impressions shallower, gradually sloping to disc at base..................... Gnypeta Thomson