I. fossor Horn, 1880: 295;

Brown, 1937: 174; Daffner, 1989: 302 (lectotype designation); Peck & Cook, 2013: 7 (lectotype seen).

Lectotype male in MCZC (n° 3191), designated in Daffner, 1989 [4 syntypes, males and females, from Detroit and District of Columbia, in original description]. Type (lectotype) locality: District of Columbia, U.S.A.

Distribution: Canada; U.S.A.; (Mexico?: Veracruz State ( uncus)). = I. uncus Wheeler, 1977: 77; Daffner, 1989: 302 syn. (this synonomy is almost certainly in error, Peck & Cook, 2013: 7, type seen). Holotype male in MCZC (n° 32322, in Daffner, 1989). Type locality: Fortin de las Flores, Veracruz State, Mexico.