Calocedrus decurrens
Many woody plant species have been reported as hosts for "H. irregulare". Hosts consist of pines and some other conifers and hardwoods, including ponderosa pine ("Pinus ponderosa"), shortleaf pine ("Pinus echinata"), red pine ("Pinus resinosa"), incense-cedar ("Calocedrus decurrens"), western juniper ("Juniperus occidentalis"), and Manzanita ("Arctostaphylos" spp.).