Golden Tortoise Beetle

Golden Tortoise Beetle! How does he change his spots?

The golden tortoise beetle or the Charidotella sexpunctata is an amazing insect! It is a North American beetle that has the ability to change its coloring reversibly from a vibrant metallic gold color to a ladybug like coloring of dull red with black spots. It is able to do this by altering the reflectivity of its cuticle so that the outer layers become clear revealing the spotty red coloring underneath. The beetle will change its coloring when disturbed by stressful external events









So how does the beetle change its coloring? Some research (Vigneron, et al, 2007) has suggested that the gold color displayed is caused by a multilayer reflector that has porous patches in each layer that are kept in a stable state by the presence of humidity. The red color displayed when the animal is threatened, is caused by the liquid that is in the porous patches being expelled therefore destroying the reflector, causing the multilayer to go translucent meaning that the red spotty layer can be seen. When the beetle no longer feels threatened water in the air will refill its pores, bringing back the gold reflective color!