Lepidoptera of Crater Lake National Park: Results from the 2019 Surveys

Ross, Dana

Crater Lake National Park Lepidoptera (butterflies and moths) were sampled three times between late June and late August 2019 in a second year of field sampling toward a present-day inventory baseline. As in 2015, the diverse habitats of the southern half of the park were targeted, with a somewhat greater emphasis on high elevation habitats and a first look at some west boundary meadows. Unlike the low precipitation winter prior to 2015 sampling, adequate high elevation snowpack provided for good plant growth and greater butterfly abundance in 2019, particularly in the open pumice habitats along East Rim Drive. Diurnal sampling documented a total of 55 species of butterflies, with as many as 23 new species for the study, and two new species for the park: namely, Propertius Duskywing (Erynnis propertius) and Great Spangled Fritillary (Speyeria cybele pugetensis). Two populations of the Sierra Blue (Agriades podarce klamathensis) were located for the first time in several decades and included one that was previously unknown. Two additional populations of Mormon Fritillary were also discovered, increasing the number of known park populations to three. Moths from 45 light trap samples and daytime surveys revealed a total of 270 species. When combined with the updated results from 2015 and with the inclusion of several micro-moths, the checklist stands at 336 species. Additional sampling in the northern half of the park as well as at lower elevation sites along both east and west slopes are needed to better describe the present-day Lepidoptera assemblage. Such coverage would elucidate the broader distributions of many common species and likely document additional uncommon to rare ones.