Raphia frater abrupta

Raphia frater abrupta replaces Raphia frater frater from the central Great Plains eastward to the mid-Atlantic seaboard, and southward to eastern Texas and Florida. It is on average smaller with a more evenly-coloured forewing, a more linear, angulate antemedial band and a fuscous hindwing. Average forewing length is 13.7 mm (n = 9) in males, 15.2 mm in females (n = 9). The thoracic collar is often darker than the dorsal thorax, not concolorous as in Raphia frater frater. The wing facies of subspecies abrupta is in many ways intermediate between Raphia frater piazzi of central and southern Texas and Raphia frater frater to the north, but the exact nature of the interface between abrupta and piazzi in Texas remains unstudied.

Subspecies abrupta occurs south of the range of the aspen species favoured by Raphia frater frater larvae, and its riparian haunts suggest it feeds on eastern cottonwood (Populus deltoides), the only Populus species in much of its range. Swamp cottonwood (Populus heterophylla) and willows (Salix spp.) may also be suitable hosts. This subspecies is apparently rare on the Atlantic seaboard and absent altogether in the Appalachians. We examined only a single historical specimen from New Jersey (Trenton), with records north of there assignable to Raphia frater frater. All Ohio records were attributed to Raphia frater frater by Rings et al. (1992), although specimens with a pale grey forewing and dusky hindwing, traits of the abrupta phenotype, rarely occur as far north as southernmost Ontario (Toronto) and southeastern Minnesota (Fillmore Co.).