Euphydryas phaeton ozarkae (Masters, 1968)

Euphydryas phaeton ozarkae (Masters, 1968) View in CoL

Prior to the description of ozarkae, W. Hoffmeister (1881) described larvae in Lee County, IA (later determined to be ssp. ozarkae ) feeding on Aureolaria pedicularia . Field (1938) first noted that specimens from Kansas and Missouri differed from phaeton in places such as Pennsylvania, New York, Maine, Wisconsin …” and suggested “Whether this material represents a new subspecies …has not yet been determined.” Masters (1968) described subspecies ozarkae from interior North American populations that inhabit a different habitat type: dry valleys, hillsides, high well-drained hilltops, and thinly wooded ridges; and that feed primarily on Aureolaria grandiflora . His description follows:

“ Male ( Figs. 1, 2). – The same general appearance as nominate E. phaeton ( Figs. 3, 4) but the red coloring is paler and of a more yellow cast. With an expanse of one forewing (base to apex) of 28 to 32 mm it is somewhat larger.

Upperside ( Fig. 1): Marginal red spots are reduced in size. Black lines over veins are wider and the black marginal band invades the red band, resulting in a wider spacing of the red spots. Red spots at apex of the forewing tend to be narrow, in no case are they wider than high. Red spots in forewing cell are not well developed – 75% of specimens have only one poorly defined spot; in the remainder one spot is weakly developed and there is a faint suggestion of the second.

Underside ( Fig. 2): White coloring tends to be “whiter” than on the nominate subspecies. Discal cluster of red spots are more broken and separated by black.

The genitalia (Fig. 9) do not differ from the nominate subspecies.

Female ( Figs. 5, 6). – The same general appearance as nominate phaeton (Figs. 7, 8) but the red coloring is reduced – often wanting altogether on upper surfaces – and is of a paler, yellower cast. Very large size – expanse of one forewing (base to apex) 31 to 38 mm.

Upperside ( Fig. 5): Forewing discal red is not present. Marginal red spots, if present, have a distinctly triangular shape and are reduced in size so that the space between them is as large as the spots themselves. White areas tend to be larger and “whiter” – four white bands are present on the forewing, fusing to three near the anal angle. Outer row of white spots are larger than marginal row of red spots on forewing.

Underside ( Fig. 6): Discal red pattern appears to be more broken because of the wider separation of the spots. White rows tend to be wider and more regular.”

At the time of the description of ozarkae, Masters (1968) gave the range of ozarkae as: Springfield, and vicinity of St. Louis, MO; Brown Co., IL; Lawrence and vic., KS; Ottawa Co., OK; and northern Arkansas. Masters commented: “While Chelone glabra is found throughout the Ozarks, I never found E. phaeton in association with it but rather with Aureolaria .” Dole, et al. (2004) indicate the range of phaeton extending into northeast Texas, and Plantago lanceolata is listed as an additional host for that region. Schlicht et al. (2007) show ozarkae in extreme southeast Iowa. Interestingly, Harris (1972) writes that all Georgia specimens to his knowledge were collected on “hillsides and mountain slopes” with the host unknown and with no evidence of Chelone glabra . This highlights the need for more detailed fieldwork to define the eastern range of ozarkae. Due to phenotypic similarity to schausi from the present analysis, the conclusion is that ozarkae can be more reliably defined by habitat and primary hostplant association. Differentiating populations of ozarkae from schausi in the intervening region of the Ohio River watershed will rely heavily on host and habitat associations rather than phenotype alone.

Literature Treatment 1969-2021

Harris (1972) refers to Georgia populations as nominotypical E. p. phaeton . [Interestingly, all cited reports are from upland habitats, suggestive of eastward influence of ozarkae.]

Irwin & Downey (1973) recognized E. p. phaeton and E. p. ozarkae separately as subspecies, and indicated their separate distributions in Illinois.

Brower (1974) treats Maine populations as E. p. borealis.

Howe (1975) lists E. p. phaeton and E. p. ozarkae at full subspecific rank, but discusses regional variation in E. phaeton with great clarity: “Through the years several names have been proposed for variations among northern, central and southern populations. E. phaeton , described from New York, has the intermediate central coloring and pattern. The name borealis …was given to the northern color variation with larger, redder marginal spots and glossy jet black coloring above. The name schausi …is characterized as being blacker in ground color, with whiter light spots and narrower orange markings. The type locality [ phaeton ] is in a transitional area.” Under the entry for subspecies E. p. phaeton : “If names are desired for these variations phaeton , borealis and schausi are available, but…these names do not represent separate populations, only the two extremes and middle of a cline.”

Opler & Krizek (1984) simply commented: “Several subspecies of uncertain merit have been proposed. The most valid of these seem to be E. phaeton phaeton and E. phaeton ozarkae Masters. These two subspecies may be distinguished on the basis of adult coloration, habitat, and food plant.”

Mather & Mather (1976, 1985) list E. phaëton ozarkae for Mississippi (1976), with a grammatical name correction to phaeton (1985).

Miller & Brown (1981) listed E. p. phaeton and E. p. ozarkae as subspecies; with schausi and borealis as junior synonyms of ssp. phaeton .

Hodges (1983) listed E. p. phaeton and E. p. ozarkae as subspecies; with schausi and borealis as junior synonyms of ssp. phaeton .

Sedman & Hess (1985) treat west central Illinois populations as subspecies ozarkae.

Scott (1986) recognized only E. p. phaeton and E. p. ozarkae as subspecies.

Vawter & Wright (1986) conducted a study of genetic differentiation between E. p. phaeton and E. p. ozarkae and found a lack of allozyme differentiation between New York and Missouri population samples. They concluded that populations so genetically similar are unlikely to be separate species. The authors erroneously stated that only “two subspecies have been described”.

Heitzman & Heitzman (1987) treat Missouri populations as subspecies ozarkae.

Shull (1987) recognized E. p. phaeton and E. p. ozarkae separately as subspecies, and noted that only nominotypical phaeton has been found in Indiana

Klassen, et al. (1989) suggest that Manitoba populations are nominotypical E. p. phaeton , but state: “The number of Baltimore subspecies is still under investigation.”

Ferris, C. D. (1989) listed E. p. phaeton and E. p. ozarkae as subspecies.

Iftner, et al. (1992) treat Ohio populations as nominotypical E. p. phaeton .

Miller (1992) recognized two subspecies, E. p. phaeton and E. p. ozarkae.

Poole & Gentili (1996) do not recognize subspecies for E. phaeton , and list schausi , borealis and ozarkae as junior synonyms.

Neck (1996) indicates the Texas records are subspecies ozarkae.

Allen (1997) treats West Virginia populations as nominotypical E. p. phaeton . However, the specimens illustrated from Elkins (plate 15, row 5) align with the schausi phenotype.

Layberry, et al. (1998) state that “only the nom nominotypical inate subspecies is found in Canada ” and do not recognize borealis. However, the specimen illustrated from Ottawa (plate 15, no. 28) is clearly borealis.

Bouseman & Sternburg (2001) recognized E. p. phaeton and E. p. ozarkae separately as subspecies, and indicated their separate distributions in Illinois.

Cech & Tudor (2005) treat E. phaeton at species rank and comment: “Baltimores living in dry, upland forest of the Ozark Mountains were formerly considered a separate race…but more recent investigations failed to support this distinction ( Vawter & Wright, 1986). Indeed, “Ozark-like” upland populations are also now known from New England and New York.” [The authors clearly do not recognize phenotypic differences for E. phaeton as qualifying for subspecific status, and no subsequent study has been done on purported dry-habitat phaeton in the northeast other than anecdotal references.]

Schlicht, et al. (2007) recognized E. p. phaeton and E. p. ozarkae separately as subspecies, and indicated their separate distributions in Iowa.

Scott (2008) recognizes only subspecies E. p. phaeton and E. p. ozarkae, then lists borealis as a synonym of E. p. phaeton , and does not recognize schausi .

Belth (2013) recognized E. p. phaeton and E. p. ozarkae separately as subspecies, and noted that only nominotypical phaeton has been found in Indiana, but that ozarkae may eventually be found in southern Indiana.

Spencer (2014) treats Arkansas populations as subspecies ozarkae.

Jeffords, et al. (2014) recognized E. p. phaeton and E. p. ozarkae separately as subspecies, and indicated their separate distributions in Illinois.

Monroe & Wright (2017) recognize Pennsylvania populations as nominotypical subspecies E. p. phaeton .

Pohl, et al. (2018) list only subspecies E. p. phaeton for Canada.

The following authors treat phaeton at species level only, for various states and regions: Acorn & Sheldon (2016); Allard (2013); Allen, et al. (2005); Betros (2008); Blakney (2015); Blakney & Gallagher (2020); Brock & Kaufman (2003); Carmichael & Vance (2003); Cossey (2016, 2017); Covell (1999); Daniels (2003, 2004a, 2004b, 2005); Douglas & Douglas (2005); Ebner (1970); Ely, et al. (1986); Feltwell & Hargreaves (1992); Glassberg (1993, 1999, 2017); Gochfeld & Burger (1997); Grehan, et al. (1995); Hall, et al. (2014); Handfield (2011); Holmes, et al. (1991); Howell & Charny (2010); Jones & Schaeffer (2012); Kiel (2003); Kimball & Jones (1943); Leboeuf & Le Tirant (2012); Mello & Hansen (2004); Nielsen (1999); O’Donnell, et al. (2007); Ogard & Bright (2010); Opler & Malikul (1998); Patterson (2011); Pyle (1981); Riotte (1992); Shapiro (1974); Shapiro & Shapiro (1973); Smith & Domingue (2019); Stichter (2015); Veilleux & Prévost (1976); Venable (2014); Wagner (2005); Weber (2002, 2006); Woodbury (1994).