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Issue link: https://wardsworld.wardsci.com/i/1456686
Page 3 1. Like spiders, caterpillars produce silk through a "spinneret." This tube-like structure is located on the lower side of the caterpillar's mouth. The caterpillar excretes liquid silk from its salivary glands then through the spinneret. When the liquid hits the air, it turns into a solid silk strand. Silk is one of the strongest natural fibers — it's said that pound for pound, silk is stronger than steel. Although, the spider's silk is stronger than not just steel, but also Kevlar!4 If you have a butterfly habitat, you can observe them attach to the roof before forming a chrysalis. The caterpillar uses silk from its spinneret to secure itself and build its chrysalis. 2. Butterflies use complex structures called photonic crystals to scatter light and create that distinctive iridescent look.5 Scientists used powerful x-rays at the Advanced Photon Source at Argonne to get a unique look at the structure of the tiny crystals that make up butterflies' wings. The results show us how the wings get their iridescent, brilliant colors. "We also found tiny crystal irregularities that may enhance light-scattering properties, making the butterfly wings appear brighter." These "defects" grow as a result of the chirality — the left or right-handedness — of the chitin molecules from which butterfly wings are formed," said co-author Ian McNulty, an X-ray physicist with the Center for Nanoscale Materials at Argonne. In addition to being extremely easy to maintain in your classroom, you can use these live critters to: • Demonstrate a full life cycle • Visualize development quickly — most develop between 14 to 26 days • Study habitats and environments 1. Butterfly Conservation: Painted Lady migration secrets revealed 2. Journal of Experimental Biology: Chitin metabolism in insects: structure, function, and regulation of chitin synthases and chitinases, Hans Merzendorfer, Lars Zimoch. 3. The Texas Butterfly Ranch. 4. Everything Silkworm: Silkworm Thread vs. Spider Thread: Strength, Thickness & Future Uses. 5. Argonne National Laboratory: X-rays reveal the photonic crystals in butterfly wings that create color, Louise Lerner. 9 facts you may not know about Painted Lady Butterflies and how to use them in the classroom (continued)