The fact that these two butterflies are locked in copulo confirms that they are of the same species, even though they display different coloration. On the right is the typical (and very common)
Clouded Sulphur; paired with him is the so-called "alba" color polymorphism seen in females, in which the yellow is replaced by white. As best I can tell from a quick web search, this reflects homozygosity for a recessive gene, but has no known functional significance.
