Twenty years of butterfly transect data from southern California with a focus on the threatened Lycaena hermes

The sage scrub vegetation community within coastal southern California has experienced substantial reductions over the last several decades. This habitat loss has resulted in population declines and distributional contractions for many native species, including several butterflies such as Euphydryas editha quino, Euphyes vestris harbisoni, Pyrgus ruralis lagunae. Concerns about the conservation status of Lycaena hermes led to the establishment of transects to conduct Pollard Walks to determine relative population sizes starting in the summer of 2003. Since that time, the foothills around San Diego have experiences large-scale wildfires in fall 2003 and 2007, and a substantial drought. The species was listed by the United State Fish and Wildlife Service as threatened in 2021 and is close to being extirpated from the United States. Butterfly community data were collected along with L. hermes counts along established transects that were monitored several times through the flight season. The community data provides important information on changes in the abundance and distributions of other butterflies. General trends in the butterfly community will be presented. In addition, a more comprehensive description of the impacts of large wildfires and drought on other butterfly species will be discussed.