Whites and Sulphurs are among some of our most abundant butterflies.  There are 1,000 species worldwide and about 60 species in North America.  Caterpillars of both tend to be green and cylindrical.  Whites are found in almost every habitat and are avid visitors to flowers.  Caterpillars of most whites feed on mustards or capers.  Sulphurs are also frequent visitors to flowers.  They are usually yellow, orange and in cases  where some females are albinos, white.  Most sulphurs sit with the wings closed so that the pattern on the upperside is seen only through the wing or when in flight.  Most sulphur caterpillars feed on legumes.