Characterisation of Natural Silk of Leaf-Rolling Caterpillar, Parotis marginata (Lepidoptera: Crambidae)

Insect silk is a protein that naturally produces semi-crystalline fibres in the air. Insects produce silk to protect themselves from rain, wind, and predator pressure when nesting. Several uses of silk have been identified because of its general strength, stiffness, and biodegradability. While the longevity of threads is well known, the characteristics of biomaterials are still unknown. These features of silk generated by the lepidopteran caterpillar Parotis marginata are shown in this study. We find approximately 60 nests in a single Tagar ( Tabernaemontana divaricata ) plant. When we spread it, we found silk (thickness: 45.0 ± 9.8 µm) on average 100 cm 2 of each nest. We obtain 6000 square centimetres (0.6 square metres) of silk from each tree. The focused mass of the silk, thickness and apparent density show its hydrophobic nature, while the X-ray powder diffraction pattern shows its crystallite sheet structure. The thermal stability and endurance of silk are shown by its thermogravimetric curve. According to Fourier transform infrared analysis, it contains alkanes, alkenes, and alkynes. The energy-dispersive X-ray findings show that the silk is mostly carbon (C), nitrogen (N), and oxygen (O), with tiny quantities of magnesium (Mg), aluminium (Al), sulphur (S), silicon (Si), and potassium (K). To the best of our knowledge, this is the first report about P. marginata properties of silk.