9 spp. in our area(1)
), dozens in the Neotropics
Adult: apex of elytra and abdomen has sharp spine (a distinctive feature)
in our area, e. US (NY-WI to FL-TX) and adjacent Canada(3)(4)
; most diverse in the Neotropics(5)
shallow pools and ponds with cattails (Typha spp.)
spines at the apex of the elytra and abdomen are used to pierce cattails and obtain oxygen without swimming to the surface (Hilsenhoff 1994)
Hilsenhoff W.L. (1994) Dytiscidae and Noteridae of Wisconsin (Coleoptera). V. Distribution, habitat, life cycle, and identification of Hydroporinae, except Hydroporus Clairville sensu lato. Great Lakes Entomologist 26: 275-295.