Basal third of the wing is nearly unmottled, but the apical part is somewhat darkened by irregular black striation.

Ground-colour creamy white, with olive hue, strigulated grey; blackish dots along costa and dorsum; diffuse grey fasciae in distal half of wing, scaled back towards apex.

Pattern often ill-defined, occasionally darker in apical area [than] in middle, or median fascia reduced to a blackish dorsal blotch.

The only Canadian specimen has whitish ground-colour indistinctly but densely strigulated olive-grey, blackish suffusion of wing base, ferruginous, edged black dorsal blotch followed by grey costal mark.

Male genitalia of Canadian specimens: Valva broad basally, then strongly tapering terminad; sacculus broad, rounded ventrally; median part of transtilla very slender, with small apical thorns; aedeagus distinctly bent; cornutus slender, straight.

[8] Throughout North America, P. lavana have been observed from Alberta, Arkansas, British Columbia, California, Colorado, Florida, Illinois, Iowa, Kentucky, Missouri, Nebraska, New Jersey, Ohio, Oklahoma, Pennsylvania, and Quebec.

[8] There are 10 specimen records listed publicly on the Barcode of Life Data System (BOLD), all of which were collected from middle North America.

[5] In 1997, Razowski classified P. lavana under the Phalonidia genus and concluded that the type-locality is Tucson (Arizona, US).