F. quadrioculata (Tullberg, 1871)

– Isotoma quadrioculata Tullberg, 1871: 152

AK Weber 1950; Hurd & Lindquist 1958; Bohnsack 1968; Challet & Bohnsack 1968; MacLean et al. 1977; Christiansen & Bellinger 1980, 1998; Danks 1981; Ryan 1981; Toda & Tanno 1983; Skidmore 1995; Babenko & Fjellberg 2006

YT Hammer 1953

NT Weber 1950; Hammer 1953; Danks 1981; Toda & Tanno 1983; Rusek 1994; Skidmore 1995; Babenko & Fjellberg 2006 NU Folsom 1919, 1937; Brown 1932; Davis 1936; Hammer 1938, 1953, 1953a; Mills & Richards 1953; Danks & Byers 1972; Addison 1975, 1977; Ryan 1977; Christiansen & Bellinger 1980, 1998; Fjellberg 1986, 1994; Babenko 1993; Niwranski et al. 2002; Hogg & Hebert 2004; Babenko & Fjellberg 2006

BC Mills & Richards 1953; Cannings 2010

AB McGuffin 1950; Christiansen & Bellinger 1980, 1998; Parsons & Parkinson 1986, 1986a; Skidmore 1995; Lindo 2014 SK Mills & Sinha 1971; Christiansen & Bellinger 1980, 1998; Skidmore 1995

MB McClure 1943; Hammer 1953; Skidmore 1995

ON Folsom 1937; Weber 1950; Christiansen & Bellinger 1980, 1998; Skidmore 1995

QC Skidmore 1995; Huebner et al. 2012

NB Pielou & Verma 1968; Christiansen & Bellinger 1980, 1998; Skidmore 1995

NF Stach 1966; Skidmore 1995

Remarks: Hogg & Hebert (2004) reported a high intraspecific divergence in this species in NT and supposed that this likely reflects the presence of an undescribed sibling species. Two different cryptic lineages (L1 and L2) were also detected for the species in MB (Porco et al. 2014).

General distribution: Holarctic.