Although it lacks the majesty of a butterfly being released form its cocoon, the caddisfly may be said to have one of the most interesting life cycles of any known insect. Ten months after being born, the caddisfly larvae will then enter its next stage of development by building itself a cocoon out of literally anything it can find, using a combination of secreted adhesive (as we might describe it) and present building materials to form a cocoon around itself, protecting itself from its surrounding environment while the pupae present within develops into an adult.
Although caddisflies have specific preferences for building materials, depending from species to species, it has been proven in multiple experiments that caddisflies will use different materials when forced out of their shells. One experiment showed that, when ejected from their cases prematurely, the caddisfly larvae will immediately rebuild their cases and do so as rapidly as possible, using whatever material is present (Hansell, 179). Another experiment shows that, oddly enough, caddisflies will actually use different materials for their cases as based on the presence of known predators, choosing stronger materials if needed (Boyero, Rincon, Bosch, 364), while yet another experiment discovered that caddisflies will select materials that will assist with the collection of oxygen (i.e. by having water pass through the case), and will use materials that are best for their specific environments.
Using this information as our stating point, this group decided to create an experiment to test the case-material preferences of caddisflies living within Itasca State Park by ejecting them from their cases, placing them in a enclosed environment, presenting them with various materials, both natural and unnatural, and observing which materials they chose to use. For the purposes of this experiment, our initial hypothesis was that caddisfly choose case-building materials that are most common to their environments (i.e. organic/natural materials), and we predicted that, when given a choice, the caddisflies we used would select to use leaves/dirt more often than the various bits of inorganic/unnatural material we gave them.
Gravel, Leaves, and Candy Bar Wrappers: An Analysis of the Case-Building Behavior of Caddisflies in An Artificial Environment.
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