Science Buddies: "Ask an Expert"

I'm a high school student currently taking a science research class. I will be testing the effect of greywater on the health of plant consumers (cabbage white butterflies). I will water some plants with tap water and some with greywater. The caterpillars will be eating the foliage of these plants. I plan to measure the number of butterflies that emerge from pupae, and also the butterflies' wingspans. Can anyone recommend any other ways to assess the health of the butterflies? Thank you.

Hi!
There are many ways to assess if butterflies are healthy. I think that the markers you have already are very important, and you might want to think about tracking mortality rates as well. It is also interesting to note that butterflies that are healthier might be able to fly further as well. The following website is also a general guide for creating the healthiest environment for butterflies (some are impossible given space limitations, but nonetheless it is a reminder of conditions that you should try to maximize):

http://www.butterflyboutique.net/pages/ ... -INTRO.pdf

You might want to think about establishing a very set criteria for determining whether or no butterflies are healthy (just like when humans go to the doctor and get a complete physical done). If this seems to be a challenge when it comes to butterflies, you might want to think about refining your project to testing something concrete about the butterflies such as the actual size of the butterfly population (which can be quantified easily). It is also important to keep in mind the many confounding variables which might be affecting your results, so creating an optimal environment (with the greywater) will make your project stronger. Best of luck!!