School of Natural Resources Seminar\: Louis Nastasi

Abstract

Species in the native plant genus Silphium (Asteraceae\: Heliantheae) have emerged in recent years as desirable oilseed, forage, and biofuel crops. However, the taxonomy of the genus is poorly understood, causing issues for crop breeding, pest management, and related areas; roughly 20 species are recognized by most publications, but preliminary molecular, morphological, and ecological data suggest many species are improperly diagnosed, and that numerous undescribed species are present throughout eastern North America. Phytophagous and parasitic wasp communities associated with these plants are extremely species-rich, with over 50 species identified to date; the extreme host specificity of these wasps suggests that multidimensional taxonomic assessment of the entire system, using wasps as a guide, may provide enormous benefits toward understanding Silphium species identities, thereby enabling crop development for various purposes.

Speaker's Bio

Dr. Nastasi's work focuses on systematics of gall wasps (Hymenoptera\: Cynipidae sensu lato) and their natural enemies (primarily Chalcidoidea), integrating molecular and collections-based methods to elucidate patterns in biodiversity and evolution, delimit and describe new taxa, and produce diagnostic resources such as identification keys. Ongoing projects emphasize the robust herb gall wasps (Aulacideini),slender herb gall wasps (Phanacidini), usurper gall wasps(Ceroptresini), and various gall wasp parasitoids (Eurytomidae and Ormyridae). Emerging projects involve gall wasp pests in crop systems and evaluation of gall wasps' ability to delimit host plant taxa.