Giant Swallowtail, a stunning butterfly
Giant Swallowtail butterflies have a wingspan of 4-6 1/2 inches making them the largest butterflies in the United States. And this one was close to the max so I was truly awed by both it's beauty and exceptional size. Giant Swallowtail butterflies range from the eastern states west to the Rocky Mountains and then across the Southwest then south as far as South America. And in 2012 they were found in Montreal, Canada which is a very surprising northern range expansion thought to be related to warming temperatures according to the Montreal Botanical Garden where they were discovered.
They are less often found in western states such as Colorado so I was fortunate to find this one.
Their black upperwings have contrasting bright yellow diagonal bars while the underwings are mostly yellow. And they have two black 'tails' with yellow in the center which sets them apart from the Schaus' swallowtail butterfly that looks almost like it. Plus they have a small amount of red and blue to highlight their spiffy appearance along with a bright yellow body.
While this species likes citrus plants in areas where they grow (certainly not in Colorado), this Giant Swallowtail flitted from one rabbitbrush plant to the next while I was photographing it. Clearly the plants that provide nectar and that host them will vary according to the location but the National Wildlife Federation has some good information in their 'Attracting Butterflies' webpage.