I conducted this project as part of Professor Pringle’s EEB321 class at Princeton University.
The plan was to look at a tardigrade under my Foldscope. In high school I learned about the existence of these amazingly hardy creatures and they’ve been one of my favorite animals ever since. Knowing that they can be found on moss, I located a patch of moss outside Guyot Hall and crouched to grab a sample. As I did so, I noticed a molt of an insect, most likely a cicada. I grabbed it as well, hoping to see some cool patterns on it.
I loaded the moss sample into the slide and peered through the lens of my Foldscope. Unfortunately, there was no tardigrade to be found, but the moss looked different from what I had expected.
From afar, moss looks just like a fuzzy carpet, so I expected it to look like grass, with multiple blades leaving from the center. Instead, I saw what looked more like sea kelp. There were multiple blades/leaves attached at different places along a long stem. This observation made me wonder what the advantages and disadvantages are to growing this way instead of growing like grass, with all the blades leaving from a central place at the base of the plant.
With just the right focus, I could barely make out the outlines of what appear to be the individual cells of the moss. It was really cool that I could see down to the cellular level (or close to it) with just a few pieces of folded paper, magnets, and a lens–all combined worth less than a dollar.
Next, in preparation for viewing the cicada molt, I used my tweezers to rip off a small piece of the (mostly intact) molt. To my surprise, there was a little black spot moving in the hollow insides of the molt. It was a winged insect, slightly smaller than a fruit fly. My interest turned to looking at this bug within a bug. I placed the insect in the slide and looked into my Foldscope.
One thing that caught my attention was the amount of hair on this insect that was no wider than a couple strands of my own hair. The antennae, legs, head, and even its wings (!) were all lined with hair. And thinking about it, there are probably cells within the insect that have hair-like cilia as well. This reminded me of how recursive and repeated patterns are not uncommon in the natural world.
Another thing I noticed was that the antennae seemed to be constructed of many little cone-shaped segments put together, similar to stacking a bunch of identical Lego pieces on top of each other. Prior to this observation, I had not thought much about insect antennae and had assumed that each antenna was just one slender hair-like structure, like a whisker. Instead, an antenna had multiple segments and contained little hairs along its length.
Even though I did not manage to find a tardigrade, I still learned new things about moss and insects–and got to experience making and using a Foldscope!