Environmental Entomology, 47(3), 2018, 646–653 doi: 10.1093/ee/nvy033 Advance Access Publication Date: 31 March 2018 Plant–Insect Interactions Research Behavioral Evidence for Host Transitions in Plant, Plant Parasite, and Insect Interactions Dale A. Halbritter,1,2,7 Denis S. Willett,3,4 Johnalyn M. Gordon,5 Lukasz L. Stelinski,3 and Jaret C. Daniels1,6 1Entomology and Nematology Department, University of Florida, 1881 Natural Area Dr, Gainesville, FL 32611, 2Present address: Invasive Plant Research Laboratory, USDA-ARS, 3225 College Avenue, Fort Lauderdale, FL 33314, 3Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, 4Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS, 1600 SW 23rd Dr, Gainesville, FL 32608, 5Fort Lauderdale Research and Education Center, University of Florida, 3205 College Avenue, Davie, FL 33314, 6McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, 3215 Hull Road, Gainesville, FL 32611, and 7Corresponding author, e-mail:
[email protected] Subject Editor: Jared Ali Received 3 November 2017; Editorial decision 26 February 2018 Abstract Specialized herbivorous insects have the ability to transition between host plant taxa, and considering the co-evolutionary history between plants and the organisms utilizing them is important to understanding plant insect interactions. We investigated the role of a pine tree parasite, dwarf mistletoe (Arceuthobium spp.) M. Bieb. Santalales: Viscaceae, in mediating interactions between Neophasia (Lepidoptera: Pieridae) butterflies and pine trees, the butterflies’ larval hosts. Mistletoe is considered the butterflies’ ancestral host, and the evolutionary transition to pine may have occurred recently. In Arizona, United States, we studied six sites in pine forest habitats: three in Neophasia menapia (Felder and R.