I conducted this project as part of Professor Pringle’s EEB321 class at Princeton University, where we were challenged to use the foldscopes to observe something interesting in our environments. I have recently found my room infested with dozens of small flying creatures who fly into my computer light (and occasionally, into my ear…) – gnats. Needless to say, this can get a bit annoying at times, so I swat them away with vicious karate chops through the air, but somehow managed to get a man down and decided to put it into my foldscope so as to get a better view of my tiny enemy.
A “gnat” is really an umbrella term for several species of small, dark, short-lived, biting or non-biting, two-winged flies that resemble mosquitoes and comprise six of the seven families in the superfamily Sciaroidea. Some people (myself included before doing this research) think that fruit flies are a type of gnat, but the two are very different – fruit flies are sleeker-bodied and of lighter color as opposed to gnats, even though both can be equally bothersome if they are flying around your room at free will. I realized it was gnats that I had in my room instead of fruit flies because of their major distinguishing features from fruit-flies – their bodies are darker and bigger, their wings have a unique Y-shaped vein, and the fact that they seemed to come out of the soil of one of my houseplants which is a typical place to find gnats since they adore their fungal soil.
Well, what I saw through the foldscope gave me a newfound level of appreciation for these complex creatures that transformed my annoyance by them into curiosity. Because my gnat was rather squished and rather big for the foldscope, I could examine its exterior wing and leg structures best.
One of the first things I saw when I focused my lens was the fascinating structure of their wing, and particularly the little hairs on its exterior. These hairs are called macrotrichia and are a regularly-ordered structure common in insect wings broadly, and according to some resources have the function of holding debris for camouflage. Interestingly enough, I also saw these hairs on their legs, but I am not sure what they are called since the macrotrichia are unique to the wings. However, I could find suggestions that their function is to taste and to smell, as well as to help their host retain balance.
Back to the wings – they have a beautiful lacewing structure that covers the whole wing surface which is barely covered by any other structures except the major Y-shaped vein, so I was fascinated by the strength of the appendage – even after I had squished the gnat and taped it to my foldscope slide, it remained one of the few parts of the organism that was relatively unfractured. This made me appreciate the strength of the wing and wonder about the deeper molecular-level structuring of the wing that allowed it to be so strong. It makes sense that this would have to be a rigorous structure that can take on strong winds and air currents, but yet it would have to be flexible so as to navigate the detailed flight patterns of the flies. I am sure the wing structure differs across insect species, but I wonder if it even differs within the same species, particularly between conspecifics in different environments who are exposed to variable environmental properties, like higher humidity or sunlight. I am now definitely much more appreciative of these flying creatures and will welcome them with open arms rather than swat them away.