Oviposition Preference of Endangered Taylor's Checkerspot Butterflies (Euphydryas editha taylori) Using Native and Non-Native Hosts

Abstract

Abstract The federally endangered Taylor's checkerspot (Euphydryas editha taylori) is an increasingly rare prairie butterfly in the Willamette Valley-Puget Trough-Georgia Basin ecoregional complex. Since the arrival of European settlers, several factors have reduced available native host plants for E. e. taylori larvae. The most common host is now Plantago lanceolata, an exotic species long prevalent in the area. Local biologists have observed that the known native hosts have low available biomass relative to P. lanceolata, and may senesce too early to support the animals throughout their entire larval feeding cycle. Federally threatened Castilleja levisecta, which often grows larger and persists longer than currently-utilized native hosts, may have been important historically but its range does not now overlap with E. e. taylori. Previous work with other E. editha ssp. has shown that oviposition preference is: 1) heritable and may provide clues to which hosts were used historically, and 2) has been corre...