Flea Fly Fo Fum

This is an image of a small insect found within the dirt of the Stanford engineering quad. After researching existing insects online, I was unable to determine the species of this critter. My initial thought was that it may resemble a termite, but after placing the scale bar on the image, I realized that the insect was too small to be classified as an adult termite (which typically measures 0.25 – 0.5” in length). The insect body was grayish-brown, but translucent under the microscope. It appears to have a shell, which is evident from the striations along the top of the body but was not discernible macroscopically. In addition, its hind legs appear to be longer than the front legs, leading to the possible classification of the insect as an outdoor flea. The view frame appears to contain the abdomen and part of the thorax.

Although I attempted to keep the bug alive when transferring it to the microscope slide, it had an extremely small and fragile body which caused it to squish slightly under the pressure of the tape. I suspect that this pressure produced the bulge visible behind the second pair of legs, although it is possible that this bulge was an existing protrusion from the body.

The mystery insect! I accidentally committed an insecticide, which led me to insecti-sigh.

To create the error bar for the sample images, I first attached the removable PVC 1 mm grid from the Foldscope kit onto a blank microscope slide. After taking a picture of the grid, I opened it in Microsoft Word and inserted a line (under the option “Insert → Shapes”) into the document. I sized this line to match the side length of one of the squares within the 1 mm grid and labeled it with “1 mm.” I then overlaid the scale bar on top of the insect image.

To produce the most accurate scale bar, it is necessary to use the same magnification level for the grid image as the sample image. This is because differences in magnification will change the relative sizes of both the grid and the sample on the captured images. If you need to change the power of your magnification between image samples, be sure to capture an image of the grid at both magnifications. Alternatively, you could place your sample directly on top of the grid; this will ensure that the relative sizes are identical on the captured image.

1 mm of mmagnification.

Please leave comments if you have theories on the identity of this insect!

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