Stripes, Sun, and Body Temperature
Monarchs are cold-blooded. A monarch's body temperature matches the temperature of its environment. Larvae can use energy from the sun to adjust their body temperature.

Cool Temperatures, Dark Larvae
This adaptation helps larvae raise their temperature, speed up their metabolism, and increase their rate of development.
Warm Temperatures, Light Larvae
This adaptation helps protect larvae from temperatures that are too high. It also slows their metabolism and their development time.