Mechanisms of resistance of poinsettias to the silverleaf whitefly

Ohio is the fifth largest producer of poinsettias in the nation with poinsettias ranking as the nation’s top selling potted ornamental valued at $242 million. The silverleaf whitefly (SLWF) is one of the most prevalent insect pests found attacking poinsettias. During the growing season growers spend millions of dollars trying to manage this insect, be it by making repeated applications of pesticides or because of losses resulting from severe infestations. Therefore, detecting plant traits useful in preventing or reducing whitefly infestations can provide additional tools for its management. Little is known about the physical and chemical traits present in poinsettia cultivars that affect whitefly life history; however, preliminary studies suggest poinsettias with dark colored leaves may be less favorable to the SLWF. Over all, dark colored leaves have lower amino acid concentrations, significantly less whitefly survival and adults settling compared to light colored leaf poinsettias. The goal of this research is to identify those traits that confer resistance. I propose to analyze physical and chemical traits of leaves including hair density, specific leaf area, and the leaf nutritional composition of poinsettias. I will associate these plant characteristics with whitefly life history traits and preference responses. This research has a potential economic impact for the private industry and a potential long term benefit for the environment. Determining the factors influencing host preference of whiteflies in poinsettias could help broaden our knowledge of other plant-insect interactions.