Spatial distribution and habitat assessment of Panoquina errans (Lepidoptera: Hesperiidae) in San Diego County, California

Abstract

Panoquina errans (Skinner, 1892), commonly known as the wandering skipper, is restricted to a narrow band of disjunct salt marsh habitat extending along the west coast of North America from Santa Barbara Co., California to the southern tip of Baja California, Mexico. A determination by the U.S. Fish and Wildlife Service of whether it represents an endangered or threatened species could not be made owing to a paucity of information on its biological vulnerability and threat. Based on a three-year survey (2010-2012) in San Diego Co., California, the species was observed in nine coastal lagoons and a coastal bluff. At all sites within the study area there was a significant correlation between the maximum annual observations of P. errans and the total area occupied by the larval host plant Distichlis spicata (Poaceae). The primary habitat for P. errans is coastal lagoons and coastal bluffs (100% of observations); elevations less than 5 m above mean sea level (98% of observations); within 25 m of patches of D. spicata over 1 m2 (75% of observations); and containing Frankenia, Cakile, or Heliotropium (95% of observations).