Pyrausta nexalis

Pale-winged Pyrausta

Family: Crambidae · Class: Insecta · Order: Lepidoptera

The pale-winged pyrausta (Pyrausta nexalis) is a small moth in the family Crambidae, subfamily Pyraustinae. Also known as the fulvous-edged pyrausta moth, this species is characterized by distinctive whitish lines on the forewings and fulvous (orange-brown) coloration along the wing bases and costa (BugGuide 2025). The forewings display a pattern of pale lines contrasting with darker ground color, while the hindwings are typically lighter with subtle markings. Pyrausta nexalis occurs across western North America, with its range extending from the Sierra Nevada Mountains of California eastward across much of the United States. In California, the species has been documented from multiple counties including San Bernardino, Fresno, Inyo, Sierra, and Calaveras counties (Moth Photographers Group 2025). Historical records indicate the type locality as the Sierra Nevada Mountains of California, where it was first described by Hulst in 1886 as Botis nexalis. The species inhabits a variety of elevations and habitat types throughout its California range. Records show occurrences from low desert areas to montane environments, with documented sightings at locations such as Kaiser Pass in Fresno County and areas near Bishop Creek Lodge in Inyo County (Lepidopterists' Society 2005). The moth appears to utilize diverse plant communities across this elevational gradient. Adult flight periods vary by location and elevation, with records spanning from spring through fall months. California observations include April records from Calaveras County and June-July activity in the Sierra Nevada region (Lepidopterists' Society 2005). Like other members of the genus Pyrausta, this species likely has multiple generations per year in favorable climates. The larvae presumably feed on herbaceous plants, consistent with the feeding habits of related pyrausta species, though specific host plant relationships for P. nexalis have not been well documented in the literature. Pyrausta nexalis is not federally or state listed, and no specific conservation concerns have been identified for this species. The moth appears to maintain stable populations across its range, with regular observations reported from various California locations. BugGuide notes there are 61 named species of Pyrausta in North America, indicating this is part of a diverse and generally successful genus (BugGuide 2025). However, like many smaller moths, detailed population monitoring and ecological studies are limited. Taxonomically, the species was originally described as Botis nexalis but was later transferred to the genus Pyrausta. It carries Hodges number 5019 in the standard North American moth classification system. The species can be distinguished from related pyrausta moths by its specific wing pattern of whitish lines and fulvous coloration, though definitive identification may require examination by specialists familiar with this taxonomically complex group.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.