A professor visited my lab to discuss teaching a new failure-analysis class. I wanted to show off my equipment, and insects are always interesting to look at in a scanning electron microscope. So I save dead bugs, when I see them, for educational purposes. Figure 1 shows the moth in question after I had broken off one of its outer wings and taped it down to an electrically conductive specimen holder (aluminum) and sputter coated it with palladium to render it electrically conductive.
The moth wing was surprisingly soft when I touched it to break it off. And even such a drab insect, with heavy camouflage, appears beautiful when you look up close. If you zoom in, you can see the individual scales have different colors. There are still-different colors visible through the palladium, even though it turns the entire wing more or less black.
Figures 2-5 show close-up views (obtained at 80-6,000x). Even after this close scrutiny, I can’t tell if the “holes” are empty or have some sort of film between the “lace network” structure. Figure 5 shows an area that looks unusual (white rectangle), but I could not tell if this was responsible for the different colors. I could not even tell if the different stripe patterns were related to the different colors we view in light or if they were a result of the angle of the electrons. But maybe that’s how the light we normally view with creates different colors.
Figure 6 shows the pointed end of the wing, where I pulled it off of the rest of the body. The different shapes of the “feather/scales” are beautiful. Figures 7 and 8 show how the scales are attached to the underlying shell of the insect. They look not so different from leaves. There are only so many shapes available for a living being to use.
As I always tell people who are learning to do failure analysis, you have to know how to look for the things that tell you why something failed. But here I certainly wasn’t looking for the cause of death of the moth. I was exercising my curiosity. Looking at what I saw, I looked more closely at interesting areas, trying to figure out (and failing) what the cause of the color variation was. If I hadn’t had to go back to work, maybe I would have had more clues after sampling more areas.
As for the cause of death of the moth, I found it whole so maybe it simply came to the end of its lifespan. Maybe it came to an early demise if it was stuck inside my office. I’ll never know. But I honor the moth and miraculous world we live in, from which something so complex and multilayered in its “ugly beauty” may emerge.