Mites Don’t Die

By Gabrielle Mendelsohn

A week after arriving at La Selva Biological Station in the Heredia Province of Costa Rica, it was time to start developing our final, independent research projects. After some discussion, my research partner, Gil, and I decided we wanted to focus on questions with pollination. After doing a brief review of the literature, we came up with some preliminary ideas looking to see if the plant community structure surrounding flowering plants impacted pollinator visitation. We brought the idea to our professor, Mauricio, confident he would approve the idea. But after having Mau poke holes in our first few ideas, we quickly learned that this project would be a little bit tricky.

When our first few ideas did not pan out, Mau helped us find a new direction. We settled on investigating the flower preferences in mites by doing choice experiments. We collected old flowers in the afternoon. In the morning we placed half of them in a bag with a cotton ball soaked in acetone for 30 minutes to kill the mites. We also went around in the afternoon to our plants and placed mesh bags over inflorescences that had a few flowers that looked like they would open the following morning. The purpose of this was to prevent hummingbirds from visiting the flowers, as the literature had suggested mites required hummingbirds to travel between inflorescences.

In the morning, we collected our new flowers and killed the mites on the old flowers. We then set up our experiment, expecting that there would be no mites in all flower treatments, allowing us to control the number of mites in each trial so we could count them and determine which flower they chose. One old flower, one new flower, one new flower cut in half, and a water droplet as a control were placed 90 degrees apart in a petri dish. Ten mites were added to each of our 10 identical petri dishes and left for 30 minutes. When counting all the flowers, we quickly realized mites had not, in fact, been excluded. We adjusted our methods again and again: placing the new flower in acetone as well, leaving flowers in acetone for longer, trying a deodorizer to kill the mites. Our first three days of data collection continued in this manner. Each time we made a change we were hopeful, and each time we became increasingly convinced that mites do not die. 

In the end, we altered our experiment to not involve mite exclusion. We were able to come up with a project that answered our initial question of flower preference in mites, albeit slightly altered, which yielded interesting and statistically significant data. The past two weeks have showed me how important it is to be flexible with research, to be willing to roll with the punches, and plan extra time to be extra thorough, because things will certainly go differently than you expect. Above all, I learned that mites will probably outlive us all.