D3406: Survivorship and mortality of immature stages of an endangered butterfly (Euchloe ausonides insulanus, Island Marble) on a novel host plant (Turritis glabra, Tower mustard)

Tuesday, November 11, 2025

9:00 AM - 5:00 PM Pacific

Location: Exhibit Hall A-A1, OCC

Presenting Author(s)

JC

Julie Combs

Washington Department of Fish and Wildlife
Seattle, Washington

Co-Author(s)

KL

Kurt Licence

Washington Department of Fish and Wildlife
Stanwood, Washington
SM

Samantha Martin

Field & Fern Consulting
Orcas Island, Washington
Staci Amburgey (she/her/hers)

Research scientist
Washington Department of Fish and Wildlife
Seattle, Washington
EG

Emma Gashi

Washington Department of Fish and Wildlife
Stanwood, Washington
MV

Melinda Vickers

Washington Department of Fish and Wildlife
Olympia, Washington
AL

Amy Lambert

University of Washington
Bothell, Washington

The island marble butterfly, Euchloe ausonides insulanus Guppy and Shepard 2001(Pieridae) is a federally endangered and is one of the most restricted butterflies in the United States. There is only one, small population located on San Juan Island, WA. Prior research documented three suitable host plants, one native and two non-native mustards. This study examines oviposition rate, larval survival and development of a prospective novel native host plant, Turritis glabra (tower mustard). We show trends in survivorship over the course of the season and discuss mortality factors at the egg and larval stage. We identify plant morphological characteristics that influence survivorship. Our data shows 11% survival to late instar stage which is comparable survivorship documented on the other three host plants. Overall, results suggest that T. glabra can support the development and survival of egg and larvae through late instar stages and therefore is a suitable host plant. We highlight conservation measures for focal species habitat restoration.