2017 ASHS Annual Conference

Native grasses act as host plants, providing food and shelter for numerous Lepidoptera species during their larval stage. As grassland habitat has diminished because of conversion to agriculture and urban areas, grassland dependent butterflies and moths have also declined. Addition of native species to urban and agriculture landscapes have shown to benefit Lepidoptera communities in various ways. Native grasses have grown in popularity as a landscaping plant due to their low nutrient requirements, drought tolerance, and soil stabilization properties. However, the benefits of native grasses to Lepidoptera are not typically known to many horticulturists, let alone the average consumer. The literature was reviewed for species of Lepidoptera that used dominant Minnesota tallgrass prairie graminoids, especially species that are widely available in the trade and could be planted for restoration or landscape purposes. Records which identified these native grasses as host plants for native Lepidoptera species in the upper Midwest region (ND, SD, MN, IA, WI, MI, IL) were included. The context of the Lepidoptera and host plant associations found in the literature were noted. The native grasses, Schizachyrium scoparium (Michx.) Nash, Bouteloua gracilis Willd. ex Kunth, and Andropogon gerardii Vitman were found to be used by the most Lepidoptera species: 15, 13, and 11, respectively. Twenty of these species belong to the Hesperiinae subfamily, which is made up of grass skippers that mostly feed from shelters constructed from grass and other substrates. Three species belong to the Satyrinae subfamily. A total of 5 moth species were recorded, from the Arctiinae, Cosmopteriginae, Anomologinae, and Noctuinae subfamilies. However, most likely there are more moth species that use these grasses as host plants in the Upper Midwest. Butterfly species are better documented than moth species so although there are many species of moths that feed or are suspected to feed on graminoids, the specific larval habits and host plant species are often unknown. This information can assist horticulturalists, ecologists, landscape planners, land managers, and homeowners in their decisions to buy and plant native grass species. In general, this knowledge provides increased awareness about the larval life stage of butterflies and moths to concerned citizens and green industry and further supports the importance of conserving native prairie to maintain Lepidoptera.