Mechanical integrity of larval shells synthesized in the presence of NikkomycinZ. Scanning electron microscopy images of shells extracted from NikkomycinZ treated larvae. a. The inner shell surface of a 5 day old larva grown in the presence of 5 μM NikkomycinZ for three days appears brittle along the borders of the flakes. b. Holes were observed in the outer shell surfaces of larvae. Here, one 19 day old example is shown. The shell was extracted after the larva was treated with 10 μM NikkomycinZ from the 8th day on.