Distribution and phenology of monarch butterfly larvae and their milkweed hosts in the South Central US

South Central US milkweeds (Asclepias) are critical adult nectar and larval food resources for producing the first spring last summer/fall generations of declining eastern migratory monarch butterflies (Danaus plexippus). This study addresses multiple gaps in assessment conservation priorities through analyses host selectivity, phenology, spatial density, as well niche modeled distribution, land cover selectivity important milkweed hosts. Results synthesized to estimate seasonal resource areas. About 70% activity occurred from mid-March mid-July (early season) 30% mid-August late November (late season). Twenty-six wild (Apocynaceae) hosts were mapped, including four new records North America. Important included Asclepias a. ssp. capricornu, A. viridis, oenotheroides, that utilized more frequently during early season, latifolia, season. Landscape was positive viridis capricornu seasons, respectively, negative oenotheroides Milkweed Developed-Open Space Grassland Herbaceous, Cultivated Crops Shrub/Scrub. Seasonal areas densities resolved interior coastal corridors providing functional connectivity fall migrations. A potential gap identified Texas. The novel merging models with informs assessment.