Could different types of butterflies breed with one another to make a new species?
Yes, individuals from two separate species occasionally mate and form hybrid offspring. Typically, this occurs between species that are very closely related. A good North American example is a population of swallowtail butterflies in upstate New York that appeared for the first time late in the summer in 1999. Genetic analysis has shown that these butterflies are a hybrid of the Canadian tiger swallowtail and the Eastern tiger swallowtail. Because they emerge late in the season, the new population is reproductively isolated from the parental populations which emerge early in summer. Presently, they can still mate with the parental species and produce healthy offspring in the lab. However, if the reproductive isolation persists for many years, over time the hybrid population will accumulate genetic differences from the two parental species, and possibly become a separate species. – Dr. Naomi Cappuccino
Source: Ording, G.J. et al. 2010. Allochronic isolation and incipient hybrid speciation in tiger swallowtail butterflies. Oecologia 162:523-531