The purpose of this project is to find out the Effects of Ultraviolet Light on Tiger Swallowtails. The goal of this project was to find out how UV light would affect the wing span, body length, and black wing coloration of tiger swallowtails (Pterourus glaucus). Two groups of tiger swallowtail pupae were exposed to UV light for 1 minute daily and 5 minutes daily, respectively. Another group received no UV light. After the adult butterflies had hatched they were frozen and mounted. Digital pictures were taken and the computer was used to measure the wing span, body length, and percentage of black wing coloration. There was no significant difference between the groups for any of the factors tested and the data did not support the research hypothesis. It was concluded that neither 1 minute nor 5 minutes of UV exposure affected the body length, wing span, or percent of black wing coloration in tiger swallowtails.