The bright colors of some insects are often the ones that capture our attention. Black can be dull and overlooked. However, black can be a sign of important biological processes. The color we see as black is caused by the absence of reflected photons. Black can indicate an area that is used for converting photons from the sun into heat. The most efficient photon collection areas will absorb the highest fraction of photons and reflect the least photons and the areas will appear black.
Insects that must thermoregulate can have basking behaviors that position their body to get the maximum heat from the sun. Basking replaces energy from stored food with solar energy. Butterfly species with large black areas on their wings may face the sun in the cool morning air to warm their bodies. In the afternoon when temperatures are warmer, the butterfly can adjust its wing position to minimize the heat gain.