Conclusions
The purpose 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). It was concluded that neither 1 minute of UV exposure nor 5 minutes of UV exposure affected the butterflies measurements. The research hypothesis, which said that the wing span and body length would decrease and the amount of black would increase, was not supported by this data.
The control group and 1 minute group both had a 75% hatching rate, while the 5 minutes group had a 50% hatching rate. This data suggests that 5 minutes of UV exposure caused a lower percentage of butterflies to hatch, but further study is needed to prove this conclusion.
The results of this study agree with McCloud and Berenbaum (1993), who found that caterpillars developed more slowly after being exposed to UV light and Tyler et. al. (1994), who discovered that there was a higher death rate for UV exposed butterflies. The results do not support the findings of Black (1997), who found that UV light caused darkening in finches.
A problem in this study occurred when approximately one-third of the butterflies had not hatched after 80 days. This resulted in less than eight data points, which violated the assumption of the ANOVA analysis. However, the means between the control and experimental groups are close enough that the results can still be considered valid.
If this experiment were to be repeated, there are several factors that could be improved upon. One improvement would be using more butterfly pupae, to make up for those who do not hatch. Another change in this study would be to add to the UV exposure time, to find the threshold for genetic mutation in tiger swallowtails and get more dramatic results. Also, it is possible that the chrysili in this study acted as barriers for the UV light, so a study could be done exposing the caterpillars to UV light.
Abstract | Introduction | Materials & Methods | Results | Bibliography | Acknowledgements | Awards
