North American Range
A common sight in the southeastern states, Horace’s Duskywing becomes rare as its range approaches Vermont. This large, darkly patterned butterfly lacks the two diagnostic ventral hindwing spots of Juvenal’s Duskywing, their palps are often “snowy” white, and though their flight times overlap, Horace’s Duskywing can be seen much later in the season. Males will nectar and puddle. To seek females, they will perch at the ends of twigs on hilltops or slopes about one foot above the ground. Mating has been observed around midday. Females deposit eggs singly on new growth of the host. Caterpillars feed on young leaves and rest in leaf nests. Caterpillars of the last brood overwinter.
Fringes are brown. Upperside of male forewing is dark brown with little contrast and no white overscaling. Upperside of female forewing is light brown with a contrasting pattern and large transparent spots. Underside of hindwing is usually without two spots below the apex. Male has a costal fold containing yellow scent scales; female has a patch of scent scales on the 7th abdominal segment.
There are no known historic records. The first and only record in Vermont was recorded on August 18, 2007 (K. Hemeon). They are double brooded in other parts of the Northeast, flying from April into September.
Distribution and Habitat
A single record reported from a field in Dummerston, Vermont. Favored habitats are open woodlands and edges, wooded swamps, power-line right-of-ways, open fields, and roadsides. Larvae feed on oaks (Quercus). Potential host plants in Vermont include, Northern Red Oak (Quercus velutina), and Scrub Oak (Quercus ilicifolia). Adults will nectar from Observed nectaring on Wild Oregano (Origanum vulgare) in Vermont. Also reported to nectar on dogbane (Apocynum), goldenrod (Salidago) and others.