Rediscovery of Apantesis eureka (Erebidae: Arctiinae: Arctiini): Contributions to the Distribution and Biology of a Great Basin Endemic

Apantesis Walker (Erebidae: Arctiinae: Arctiini) is a moderately large genus, ca. 45 species, of often colorful moths that is most diverse in the grasslands of North America. The genus was recently expanded to include three other genera, Grammia Rambur, Holarctia Smith and Notarctia Smith (Rönkä et al. 2016). Two additional genus-group names, Mimarctia Neumögen & Dyar and Orodemnias Wallengren, were considered junior subjective synonyms prior to that study (Schmidt 2009), although erroneously stated as new synonyms therein. Many species of Apantesis are common and familiar moths that are readily encountered at lights, whether it be traps, light and sheet, or porch light. However, some species in the genus, such as A. edwardsii (Stretch), A. brillians (Schmidt), A. fergusoni (Schmidt), and A. eureka (Ferguson & Schmidt), are infrequently collected and known to science from very few specimens (Schmidt 2009). We here report new observations of A. eureka, representing the first records of the species in over a century. Apantesis eureka was described by Ferguson and Schmidt (2007) from specimens collected in 1909 and 1910 at the eastern edge of the Great Basin, USA. The specimens in the original description included the male holotype and a male and female paratype from Eureka, Utah, hence the species name. The species was not collected again except for an additional female paratype (Fig. 1a). This specimen was received in the 1950s by Douglas C. Ferguson from Jim Manning, a butterfly collector based in Boise, Idaho. Although the specimen bore no original data, it was assumed that the collection locality was in the vicinity of Boise, Idaho (Ferguson & Schmidt 2007). As such, the northern range of this species is uncertain due to the lack of specimen label data. These four specimens are the only records for A. eureka, and knowledge about the species is extremely limited. Ferguson and Schmidt (2007) speculated that the paucity of A. eureka records was likely a result of the species being diurnal. Relative to similar species, such as Journal of the Lepidopterists’ Society 76(3), 2022, 210–213