While the Bagworm moths are usually considered pests, their early stage survival technique is a brilliant example of architectural wonder of nature. The bagworm caterpillar builds a structure for itself to save itself from the predators as soon as it hatches. The caterpillar usually finds objects from the debris around itself, like twigs and leaves, to build its cocoon. The final product looks exceptionally similar to a woodhouse or a “log cabin”. Technically, these are also called cases, giving the Bagworm another name, that is, the “Case Moth”.
A tiny structure which looks like little logs stacked on top of each other, this cocoon is really strong, resilient and looks beautiful due to its symmetry and precision. Lepidopterists observe that these “log cabins” are usually built straight up or in a Fibonacci circle. They are also the perfect camouflage since the raw material is plant-based from their own surroundings.
The Bagworm, showing its incredible strength, is also required to carry their architecture around while it looks for food, or excretes. The little opening at the end helps it for its cause and it may even seal it if it senses danger, later opening another one. As the caterpillar grows, it continues to rebuild its case by adding new “logs” at the top. The adult Bagworm Moth later emerges from the lower opening.
While these shelters are pretty tiny, ranging between 1 cm to 15cm, they are really tough to break open. Females live in these cases almost all their life, only occasionally appearing to mate. Males, on the other hand, fly out of their case as soon as they pupate. They are required to extend their abdomen into the female’s case to mate with them. The females lay their eggs in their old cases and once they hatch the new larvae build their own little “log cabins”.
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